@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Nunito:wght@700;800;900&display=swap');

:root {
  --ink: #283449;
  --muted: #707c91;
  --cream: #fbf7f0;
  --paper: #fffdf9;
  --line: #e8e3da;
  --coral: #ef735f;
  --coral-dark: #db5b4a;
  --blue: #5174d8;
  --blue-soft: #edf2ff;
  --green: #62ae87;
  --green-soft: #e9f6ed;
  --yellow: #f8cb61;
  --peach: #fff0ea;
  --shadow: 0 20px 50px rgba(58, 64, 80, .08);
}

* { box-sizing: border-box; }

html { width: 100%; min-height: 100%; overflow-x: hidden; scroll-behavior: smooth; -webkit-text-size-adjust: 100%; touch-action: pan-y; }

body {
  margin: 0;
  width: 100%;
  min-height: 100%;
  overflow-x: hidden;
  color: var(--ink);
  background: var(--cream);
  font-family: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  -webkit-font-smoothing: antialiased;
  touch-action: pan-y;
  overscroll-behavior-x: none;
}

button, input { font: inherit; }
button { cursor: pointer; }
button:focus-visible, input:focus-visible { outline: 4px solid rgba(81, 116, 216, .28); outline-offset: 3px; }

.app-shell { width: min(1120px, calc(100% - 48px)); margin: 0 auto; padding: 26px 0 28px; }

.topbar { display: flex; align-items: center; justify-content: space-between; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); font-size: 17px; font-weight: 800; letter-spacing: -.03em; text-decoration: none; }
.brand em { color: var(--coral); font-style: normal; }
.brand-mark { display: grid; place-items: center; width: 31px; height: 31px; border-radius: 10px; color: white; background: var(--coral); font-family: Nunito, sans-serif; font-size: 24px; font-weight: 900; transform: rotate(-7deg); }
.topbar-actions { display: flex; align-items: center; gap: 18px; }
.session-note { color: var(--muted); font-size: 12px; font-weight: 700; letter-spacing: .04em; text-transform: uppercase; }
.sparkle { color: var(--yellow); margin-right: 5px; font-size: 17px; }
.session-button { display: inline-flex; align-items: center; gap: 7px; padding: 5px 10px 5px 5px; border: 1px solid transparent; border-radius: 30px; color: var(--ink); background: transparent; font-size: 12px; font-weight: 800; transition: border .2s, background .2s; }.session-button:hover { border-color: var(--line); background: var(--paper); }.session-mini-icon { display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; color: #ad7831; background: #fff1cf; font-size: 17px; }
.subject-button { display: inline-flex; align-items: center; gap: 7px; padding: 5px 10px 5px 5px; border: 1px solid transparent; border-radius: 30px; color: var(--ink); background: transparent; font-size: 12px; font-weight: 800; transition: border .2s, background .2s; }
.subject-button:hover { border-color: var(--line); background: var(--paper); }
.subject-mini-icon { display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; color: #3b815d; background: var(--green-soft); font-family: Nunito, sans-serif; font-size: 19px; font-weight: 900; }
.name-button { display: inline-flex; align-items: center; gap: 7px; padding: 5px 9px 5px 5px; border: 1px solid transparent; border-radius: 30px; color: var(--ink); background: transparent; font-size: 12px; font-weight: 800; transition: border .2s, background .2s; }
.name-button:hover { border-color: var(--line); background: var(--paper); }
.name-avatar { display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; color: #4962bd; background: var(--blue-soft); font-family: Nunito, sans-serif; font-size: 14px; font-weight: 900; }
.name-edit { color: #9aa2af; font-size: 13px; }
.icon-button { display: grid; place-items: center; width: 43px; height: 43px; border: 1px solid var(--line); border-radius: 50%; color: var(--ink); background: var(--paper); box-shadow: 0 3px 10px rgba(60, 62, 75, .04); font-size: 18px; transition: transform .2s ease, box-shadow .2s ease; }
.icon-button:hover { transform: translateY(-2px); box-shadow: 0 7px 18px rgba(60, 62, 75, .1); }

.hero { display: grid; grid-template-columns: 1.06fr .94fr; align-items: center; min-height: 310px; padding: 56px 44px 38px; }
.eyebrow, .section-kicker { margin: 0 0 14px; color: var(--coral); font-size: 11px; font-weight: 800; letter-spacing: .14em; }
.dot { display: inline-block; width: 7px; height: 7px; margin: 0 8px 1px 0; border-radius: 50%; background: var(--green); }
h1, h2 { font-family: Nunito, 'DM Sans', sans-serif; letter-spacing: -.045em; }
h1 { margin: 0; font-size: clamp(42px, 5vw, 66px); line-height: .98; font-weight: 900; }
h1 span { color: var(--coral); }
h1 .name-highlight { color: var(--blue); }
.hero-copy > p { max-width: 390px; margin: 19px 0 0; color: var(--muted); font-size: 16px; line-height: 1.55; }
.hero-badges { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.hero-badges span { padding: 8px 12px; border: 1px solid #eee8df; border-radius: 30px; color: #667186; background: rgba(255, 253, 249, .7); font-size: 12px; font-weight: 700; }
.hero-illustration { position: relative; width: min(100%, 380px); height: 230px; margin: 0 auto; }
.shape { position: absolute; display: grid; place-items: center; border-radius: 22px; font-family: Nunito, sans-serif; font-weight: 900; box-shadow: 0 13px 25px rgba(54, 70, 92, .12); }
.shape-a { top: 33px; left: 31px; width: 105px; height: 105px; color: #fff; background: var(--coral); font-size: 58px; transform: rotate(-10deg); }
.shape-b { top: 8px; right: 47px; width: 88px; height: 88px; color: #fff; background: var(--blue); border-radius: 50%; font-size: 50px; transform: rotate(12deg); }
.shape-c { bottom: 18px; left: 113px; width: 82px; height: 82px; color: #5c4d29; background: var(--yellow); font-size: 42px; transform: rotate(8deg); }
.shape-d { right: 4px; bottom: 23px; width: 93px; height: 93px; color: #255c46; background: #9ad2ad; font-size: 47px; transform: rotate(-9deg); }
.shape-e { top: 95px; left: 181px; width: 67px; height: 67px; color: #4e4d8b; background: #b5b5f0; border-radius: 18px; font-size: 36px; transform: rotate(5deg); z-index: 2; }
.orbit { position: absolute; border: 2px dashed #d7d2c5; border-radius: 50%; }
.orbit-one { top: 22px; left: 10px; width: 300px; height: 190px; transform: rotate(-17deg); }
.orbit-two { top: 27px; left: 61px; width: 260px; height: 160px; transform: rotate(37deg); border-color: #e2dfd5; }

.practice-card { padding: 34px 38px 0; overflow: hidden; border: 1px solid #ebe5dc; border-radius: 28px; background: var(--paper); box-shadow: var(--shadow); }
.practice-header, .section-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; }
h2 { margin: 0; font-size: 28px; line-height: 1.1; }
.today-name { color: var(--blue); }
.round-settings { display: flex; flex-direction: column; align-items: flex-end; gap: 6px; margin-top: 1px; }
.round-settings label { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 10px; font-weight: 800; letter-spacing: .07em; }
.round-settings label small { color: #a6adba; font-size: 9px; font-weight: 600; letter-spacing: 0; text-transform: none; }
.length-control { display: flex; align-items: center; gap: 6px; }
.length-control input { width: 61px; height: 37px; padding: 0 5px; border: 1px solid #dfe4f5; border-radius: 10px; color: var(--blue); background: var(--blue-soft); font-family: Nunito, sans-serif; font-size: 20px; font-weight: 900; text-align: center; }
.length-control input::-webkit-inner-spin-button, .length-control input::-webkit-outer-spin-button { opacity: 1; }
.length-apply { height: 37px; padding: 0 11px; border: 1px solid #dfe4f5; border-radius: 10px; color: var(--blue); background: #fff; font-size: 11px; font-weight: 800; transition: background .15s, transform .15s; }
.length-apply:hover { background: var(--blue-soft); transform: translateY(-1px); }
.round-settings.is-error label small { color: var(--coral-dark); }
.round-settings.is-confirmed label small { color: var(--green); }
.mode-tabs { display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; margin-top: 27px; }
.mode-tab { display: grid; grid-template-columns: 42px 1fr 20px; align-items: center; gap: 10px; min-height: 73px; padding: 12px 15px; border: 1.5px solid #ece8e0; border-radius: 15px; color: var(--ink); background: #fff; text-align: left; transition: border .2s, background .2s, transform .2s; }
.mode-tab:hover { transform: translateY(-2px); border-color: #c9d3f2; }
.mode-tab.is-active { border-color: var(--blue); background: var(--blue-soft); }
.tab-icon { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 13px; font-family: Nunito, sans-serif; font-size: 27px; font-weight: 900; }
.multiply-icon { color: #b74f41; background: #ffd7d1; }
.divide-icon { color: #4962bd; background: #d7e0ff; }
.mixed-icon { color: #4e8c6c; background: #d8f0dc; font-size: 21px; }
.arcs-icon { color: #a05d9d; background: #f5ddf1; font-size: 28px; line-height: 1; }
.split-icon { color: #ca8a38; background: #fff0cf; font-size: 29px; line-height: 1; }
.mode-tab strong { display: block; font-size: 14px; }
.mode-tab small { display: block; margin-top: 4px; color: var(--muted); font-size: 10px; font-weight: 500; }
.tab-check { display: grid; place-items: center; width: 18px; height: 18px; border: 1.5px solid #d8dce4; border-radius: 50%; color: transparent; font-size: 12px; font-weight: 900; }
.mode-tab.is-active .tab-check { border-color: var(--blue); color: #fff; background: var(--blue); }
.mode-selector { margin-top: 27px; }
.mode-selector-kicker { margin: 0 0 9px; color: #8b94a4; font-size: 10px; font-weight: 800; letter-spacing: .12em; }
.operation-tabs, .method-tabs { display: grid; gap: 10px; }
.operation-tabs { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.method-menu { margin-top: 16px; padding: 14px; border: 1px solid #ebe5dc; border-radius: 18px; background: #fffdf9; }
.method-menu .mode-selector-kicker { margin-bottom: 9px; }
.method-tabs { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; }
.operation-tab, .method-tab { display: grid; grid-template-columns: 42px 1fr 18px; align-items: center; gap: 10px; min-height: 68px; padding: 10px 12px; border: 1.5px solid #ece8e0; border-radius: 15px; color: var(--ink); background: #fff; text-align: left; transition: border .2s, background .2s, transform .2s; }
.operation-tab:hover, .method-tab:hover { transform: translateY(-2px); border-color: #c9d3f2; }
.operation-tab.is-active { border-color: var(--blue); background: var(--blue-soft); }
.method-tab.is-active { border-color: #a66aa1; background: #fcf4fb; }
.operation-tab strong, .method-tab strong { display: block; font-size: 13px; }
.operation-tab small, .method-tab small { display: block; margin-top: 4px; color: var(--muted); font-size: 10px; font-weight: 500; line-height: 1.2; }
.operation-tab .tab-check, .method-tab .tab-check { flex: 0 0 auto; }
.operation-tab.is-active .tab-check { border-color: var(--blue); color: #fff; background: var(--blue); }
.method-tab.is-active .tab-check { border-color: #a66aa1; color: #fff; background: #a66aa1; }
.method-tab-icon { display: grid; place-items: center; width: 39px; height: 39px; border-radius: 13px; color: #a05d9d; background: #f5ddf1; font-family: Nunito, sans-serif; font-size: 23px; font-weight: 900; }
.split-method-icon { color: #ca8a38; background: #fff0cf; }
.arcs-method-icon { color: #5873c8; background: #e2e8ff; }
.method-menu-hint { margin: 10px 2px 0; color: #8d94a4; font-size: 10px; line-height: 1.4; }
.method-tab[hidden] { display: none; }

.practice-area { display: grid; grid-template-columns: 1.05fr .95fr; gap: 44px; align-items: center; max-width: 850px; margin: 31px auto 27px; }
.question-meta { display: flex; align-items: center; justify-content: space-between; margin-bottom: 10px; color: #8b94a4; font-size: 10px; font-weight: 800; letter-spacing: .12em; }
.streak-label { color: #c4862f; letter-spacing: .02em; text-transform: none; }
.flame { color: #f3ad47; font-size: 15px; }
.progress-track { height: 7px; overflow: hidden; border-radius: 10px; background: #f0eee9; }
.progress-fill { width: 0%; height: 100%; border-radius: inherit; background: linear-gradient(90deg, #758ee2, #9bb0fa); transition: width .35s ease; }
.question-box { min-height: 218px; margin-top: 21px; padding: 31px 24px 24px; border-radius: 21px; background: #f8f7f3; text-align: center; }
.operation { font-family: Nunito, sans-serif; font-size: clamp(45px, 6vw, 65px); font-weight: 900; letter-spacing: -.03em; }
.answer-row { margin-top: 11px; }
.answer-row input { width: 115px; height: 58px; padding: 0 8px; border: 2px solid #d8def5; border-radius: 12px; outline: 0; color: var(--blue); background: #fff; font-family: Nunito, sans-serif; font-size: 42px; font-weight: 900; line-height: 1; text-align: center; box-shadow: 0 3px 8px rgba(40, 52, 73, .04); }
.answer-row input[readonly] { pointer-events: none; cursor: default; }
.answer-row input:focus { border-color: var(--blue); outline: 4px solid rgba(81, 116, 216, .14); }
.answer-row input.is-correct { border-color: var(--green); color: #2f8158; background: var(--green-soft); }
.answer-row input.is-wrong { border-color: var(--coral); color: var(--coral-dark); background: #fff0ec; }
.answer-hint { margin: 15px 0 0; color: #9199a7; font-size: 11px; }
.feedback { margin-top: 12px; padding: 10px 14px; border-radius: 10px; font-size: 13px; font-weight: 700; text-align: center; }
.feedback.correct { color: #2f8158; background: var(--green-soft); }
.feedback.try-again { color: #a56539; background: #fff3df; }
.feedback[hidden] { display: none; }
.simple-answer-action { display: flex; justify-content: center; margin-top: 16px; }
.simple-check-button { width: min(100%, 300px); }
.tip-strip { display: flex; align-items: center; gap: 12px; margin: 0 -38px; padding: 16px 38px; color: #6e737e; background: #fcf4dd; font-size: 12px; line-height: 1.45; }
.tip-icon { font-size: 22px; }
.tip-strip strong { color: #b27031; }
.subject-panel[hidden] { display: none; }
.practice-area[hidden] { display: none; }
.split-practice-area[hidden] { display: none; }
.english-practice-area[hidden] { display: none; }

.english-practice-area { max-width: 700px; margin: 31px auto 27px; }
.english-board { padding: 29px 28px 25px; border: 1px solid #dce9e1; border-radius: 21px; background: #f8fcf8; text-align: center; }
.english-board-heading h3 { margin: 0; font-family: Nunito, sans-serif; font-size: 25px; letter-spacing: -.035em; }
.english-board-heading p:last-child { max-width: 430px; margin: 9px auto 0; color: #819087; font-size: 12px; line-height: 1.45; }
.english-word-card { display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr); align-items: center; gap: 18px; max-width: 580px; margin: 25px auto 0; padding: 18px 20px; border: 1px solid #dbe9dd; border-radius: 18px; background: #fff; }
.english-word-group { display: flex; min-width: 0; flex-direction: column; align-items: center; gap: 7px; }
.english-plural-group { width: 100%; }
.english-word-label { color: #799184; font-size: 9px; font-weight: 800; letter-spacing: .1em; }
.english-word { max-width: 100%; overflow-wrap: anywhere; color: #315743; font-family: Nunito, sans-serif; font-size: clamp(25px, 4vw, 38px); letter-spacing: -.03em; }
.english-word-arrow { flex: 0 0 auto; color: #e0a34c; font-family: Nunito, sans-serif; font-size: 28px; font-weight: 900; line-height: 1; }
.english-answer-input { width: 100%; min-width: 0; height: 52px; padding: 0 9px; border: 2px solid #a9d0b4; border-radius: 12px; color: #2f8158; background: #fbfffc; font-family: Nunito, sans-serif; font-size: 25px; font-weight: 900; text-align: center; outline: 0; }
.english-answer-input:focus { border-color: var(--blue); outline: 4px solid rgba(81, 116, 216, .14); }
.english-answer-input.is-correct { border-color: var(--green); color: #2f8158; background: var(--green-soft); }
.english-answer-input.is-wrong { border-color: var(--coral); color: var(--coral-dark); background: #fff0ec; }
.english-answer-hint { min-height: 18px; margin: 13px 0 12px; color: #819087; font-size: 11px; }
.english-check-button { width: min(100%, 320px); }
.english-rules-panel { margin-top: 18px; padding: 25px 24px 23px; border: 1px solid #e7e1d6; border-radius: 21px; background: #fffdf8; }
.english-rules-heading { text-align: center; }
.english-rules-heading h3 { margin: 0; font-family: Nunito, sans-serif; font-size: 22px; letter-spacing: -.03em; }
.english-rules-heading p:last-child { max-width: 500px; margin: 8px auto 0; color: var(--muted); font-size: 11px; line-height: 1.45; }
.english-rules-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 9px; margin-top: 19px; }
.english-rule-card { display: grid; grid-template-columns: 39px minmax(0, 1fr); align-items: start; gap: 10px; min-height: 94px; padding: 12px 11px; border: 1px solid #eee8dc; border-radius: 14px; background: #fff; }
.english-rule-badge { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 11px; color: #fff; font-family: Nunito, sans-serif; font-size: 15px; font-weight: 900; }
.english-rule-card h4 { margin: 1px 0 5px; color: var(--ink); font-size: 11px; line-height: 1.25; }
.english-rule-card p { margin: 0; color: var(--muted); font-size: 10px; line-height: 1.4; }
.english-rule-card p strong { color: #315743; font-family: Nunito, sans-serif; font-size: 11px; }
.english-rule-s .english-rule-badge { background: #62ae87; }
.english-rule-es .english-rule-badge { background: #e0a34c; }
.english-rule-ies .english-rule-badge { background: #8a70c5; }
.english-rule-ves .english-rule-badge { background: #5f8fc4; }
.english-rule-irregular .english-rule-badge { background: #e27662; }
.english-rule-same .english-rule-badge { background: #819087; }

.split-practice-area { max-width: 820px; margin: 31px auto 27px; }
.split-board { padding: 27px 28px 22px; border: 1px solid #ebe5dc; border-radius: 21px; background: #fffaf0; }
.split-board-heading { text-align: center; }
.split-board-heading .section-kicker { margin-bottom: 8px; color: #c4862f; }
.split-board-heading h3 { margin: 0; font-family: Nunito, sans-serif; font-size: 24px; letter-spacing: -.035em; }
.split-board-heading p:last-child { max-width: 470px; margin: 9px auto 0; color: var(--muted); font-size: 12px; line-height: 1.45; }
.split-main-equation { display: flex; align-items: center; justify-content: center; gap: 12px; min-height: 75px; margin: 20px auto 17px; color: var(--ink); font-family: Nunito, sans-serif; font-size: clamp(36px, 5vw, 56px); font-weight: 900; letter-spacing: -.04em; }
.split-answer-panel { max-width: 620px; margin: 20px auto 17px; padding: 17px 19px 19px; border: 1px solid #dfe3f6; border-radius: 18px; background: #f8f9ff; }
.split-answer-panel[hidden] { display: none; }
.split-answer-heading { margin-bottom: 13px; text-align: center; }.split-answer-heading .section-kicker { margin-bottom: 6px; color: #6474b9; }.split-answer-heading h4 { margin: 0; color: var(--ink); font-family: Nunito, sans-serif; font-size: 18px; letter-spacing: -.025em; }
.split-product-answer[hidden], .split-final-answer[hidden] { display: none; }
.split-product-answer { display: block; }
.split-product-grid { display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr); align-items: center; gap: 10px; }
.split-product-item { display: flex; align-items: center; justify-content: center; gap: 7px; min-width: 0; padding: 8px 9px; border: 1px solid #e1e5f7; border-radius: 12px; background: #fff; cursor: text; }
.split-product-formula, .split-total-formula { color: var(--ink); font-family: Nunito, sans-serif; font-size: 17px; font-weight: 900; white-space: nowrap; }
.split-products-plus { color: #7886bf; font-family: Nunito, sans-serif; font-size: 25px; font-weight: 900; }
.split-product-input { width: 92px; height: 49px; padding: 0 5px; border: 2px solid #c8d2f4; border-radius: 11px; color: var(--blue); background: #fff; font-family: Nunito, sans-serif; font-size: 27px; font-weight: 900; text-align: center; outline: 0; }
.split-product-input:focus, .split-decomposition-input:focus { border-color: var(--blue); outline: 4px solid rgba(81, 116, 216, .14); }
.split-product-input.is-correct, .split-decomposition-input.is-correct { border-color: var(--green); color: #2f8158; background: var(--green-soft); }
.split-product-input.is-wrong, .split-decomposition-input.is-wrong { border-color: var(--coral); color: var(--coral-dark); background: #fff0ec; }
.split-final-answer { display: flex; align-items: center; justify-content: center; gap: 9px; margin-top: 13px; padding-top: 13px; border-top: 1px dashed #cbd3ef; color: #4b966b; }
.split-final-input { width: 92px; height: 49px; padding: 0 5px; border: 2px solid #9fc9ad; border-radius: 11px; color: #2f8158; background: #fbfffc; font-family: Nunito, sans-serif; font-size: 27px; font-weight: 900; text-align: center; outline: 0; }
.split-final-input:focus { border-color: var(--blue); outline: 4px solid rgba(81, 116, 216, .14); }
.split-final-input.is-correct { border-color: var(--green); color: #2f8158; background: var(--green-soft); }
.split-final-input.is-wrong { border-color: var(--coral); color: var(--coral-dark); background: #fff0ec; }
.split-balloon { position: relative; max-width: 620px; margin: 10px auto 17px; padding: 20px 24px 22px; border: 2px solid #efcf8a; border-radius: 28px; background: #fff; box-shadow: 0 8px 18px rgba(117, 93, 37, .08); }
.split-balloon::after { position: absolute; top: -17px; bottom: auto; left: var(--split-tail-left, 42%); width: 27px; height: 27px; border-top: 2px solid #efcf8a; border-left: 2px solid #efcf8a; background: #fff; content: ''; transform: translateX(-50%) rotate(45deg); }
.split-balloon.is-verified { border-color: #9fc9ad; background: #fbfffc; }
.split-balloon.is-verified::after { border-color: #9fc9ad; background: #fbfffc; }
.split-balloon-title { margin: 0 0 14px; color: #9c6d25; font-size: 13px; font-weight: 800; text-align: center; }.split-balloon-title strong { color: var(--ink); font-family: Nunito, sans-serif; font-size: 21px; }
.split-decomposition { display: grid; grid-template-columns: 1fr auto 1fr; align-items: end; gap: 14px; max-width: 430px; margin: 0 auto; }
.split-decomposition.is-many { display: grid; align-items: end; gap: 7px; width: 100%; max-width: 100%; }
.split-decomposition.is-three { grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr) auto minmax(0, 1fr); }
.split-decomposition.is-four { grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr) auto minmax(0, 1fr) auto minmax(0, 1fr); }
.split-decomposition.is-many .split-part-field { min-width: 0; }
.split-decomposition.is-many .split-decomposition-input { width: min(112px, 100%); }
.split-decomposition.is-many .split-part-field > span { max-width: 100%; overflow: hidden; text-align: center; text-overflow: ellipsis; white-space: nowrap; }
.split-decomposition.is-many .split-plus { padding: 0 1px 8px; line-height: 1; text-align: center; }
.split-part-field { display: flex; flex-direction: column; align-items: center; gap: 5px; color: #7e8799; font-size: 9px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.split-decomposition-input { width: 112px; height: 51px; padding: 0 5px; border: 2px solid #ead9ac; border-radius: 12px; color: #a87529; background: #fffdf6; font-family: Nunito, sans-serif; font-size: 28px; font-weight: 900; text-align: center; outline: 0; }
.split-plus { padding-bottom: 8px; color: #d39436; font-family: Nunito, sans-serif; font-size: 29px; font-weight: 900; }
.split-instruction { min-height: 20px; margin: 23px 0 12px; color: #8d8066; font-size: 11px; text-align: center; }
.split-step-action { margin: 16px auto 0; }
.split-step-action[hidden] { display: none; }
.split-action-button { display: block; width: min(100%, 320px); margin: 0 auto; }
.split-balloon.is-verified .split-balloon-title { color: #43835b; }.split-balloon.is-verified .split-decomposition-input { border-color: #9fc9ad; }
.split-part-field[hidden], .split-plus[hidden], .split-product-item[hidden], .split-products-plus[hidden] { display: none; }
.split-product-grid.is-many { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.split-product-grid.is-division { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.arc-practice-area[hidden] { display: none; }
.arc-practice-area { max-width: 960px; margin: 31px auto 27px; }
.arc-mode-tabs { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin-bottom: 22px; }
.arc-mode-tab { display: grid; grid-template-columns: 39px 1fr 18px; align-items: center; gap: 9px; min-height: 64px; padding: 10px 12px; border: 1.5px solid #ece8e0; border-radius: 15px; color: var(--ink); background: #fff; text-align: left; transition: border .2s, background .2s, transform .2s; }
.arc-mode-tab:hover { transform: translateY(-2px); border-color: #d2b5d0; }.arc-mode-tab.is-active { border-color: #a05d9d; background: #fbf0fa; }.arc-mode-tab.is-active .tab-check { border-color: #a05d9d; color: #fff; background: #a05d9d; }
.arc-mode-icon { display: grid; place-items: center; width: 39px; height: 39px; border-radius: 12px; color: #a05d9d; background: #f5ddf1; font-family: Nunito, sans-serif; font-size: 25px; font-weight: 900; }.hard-arc-tab-icon { color: #5d65b8; background: #e0e1ff; font-size: 20px; }
.arc-mode-tab strong { display: block; font-size: 13px; }.arc-mode-tab small { display: block; margin-top: 3px; color: var(--muted); font-size: 9px; font-weight: 500; line-height: 1.25; }
.arc-range-control { margin: -7px 0 0; padding: 12px 14px 11px; border: 1px solid #eee8f0; border-radius: 15px; background: #fffafd; }
.arc-range-heading { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; }
.arc-range-label { color: #5f6678; font-size: 10px; font-weight: 900; letter-spacing: .08em; text-transform: uppercase; }
.arc-range-note { color: #9a9eaa; font-size: 9px; }
.arc-range-options { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; margin-top: 8px; }
.arc-range-option { min-height: 47px; padding: 7px 10px; border: 1px solid #e5e2e9; border-radius: 11px; color: var(--ink); background: #fff; text-align: left; transition: border .15s, background .15s, transform .15s; }
.arc-range-option:hover { transform: translateY(-1px); border-color: #cbb7d0; }.arc-range-option.is-active { border-color: #a05d9d; background: #fbf0fa; box-shadow: inset 0 0 0 1px rgba(160, 93, 157, .12); }.arc-range-option strong { display: block; font-size: 11px; }.arc-range-option small { display: block; margin-top: 3px; color: var(--muted); font-size: 9px; }.arc-range-option.is-active small { color: #8a5488; }
.arc-range-hint { margin: 7px 0 0; color: #8d91a0; font-size: 10px; line-height: 1.35; }
.arc-workspace { display: grid; grid-template-columns: minmax(0, 1.18fr) minmax(265px, .82fr); gap: 24px; align-items: start; margin-top: 22px; }
.arc-board, .arc-check-card, .arc-total-card { border: 1px solid #ebe5dc; border-radius: 21px; background: #fff; }
.arc-board { min-width: 0; padding: 22px 20px 15px; background: #fbfaff; }
.arc-board-heading h3, .arc-check-card h3, .arc-total-card h3 { margin: 0; font-family: Nunito, sans-serif; font-size: 19px; letter-spacing: -.035em; }
.arc-board-heading .section-kicker { margin-bottom: 8px; color: #a05d9d; }
.arc-board-heading > p:last-child { max-width: 470px; margin: 8px 0 0; color: var(--muted); font-size: 11px; line-height: 1.45; }
.arc-canvas { position: relative; min-height: 335px; margin-top: 8px; overflow: hidden; }
.arc-lines { position: absolute; z-index: 1; inset: 0; width: 100%; height: 100%; overflow: visible; pointer-events: none; }
.arc-line { fill: none; stroke-width: 3; stroke-linecap: round; opacity: .72; }
.arc-line-tt { stroke: #7a8fe1; }
.arc-line-tu { stroke: #e88b75; }
.arc-line-ut { stroke: #65ae88; }
.arc-line-uu { stroke: #e0ad4b; }
.arc-equation { position: absolute; z-index: 2; top: 91px; left: 7%; right: 7%; display: flex; align-items: center; justify-content: center; gap: clamp(10px, 2.4vw, 22px); text-align: center; }
.arc-digit, .arc-symbol { font-family: Nunito, sans-serif; font-size: clamp(34px, 5vw, 56px); font-weight: 900; line-height: 1; }
.arc-factor-group { display: inline-flex; gap: 2px; }
.arc-digit { display: grid; place-items: center; width: 46px; height: 58px; border-radius: 14px; color: var(--ink); background: rgba(255, 255, 255, .88); box-shadow: 0 3px 10px rgba(58, 64, 80, .07); }
.arc-symbol { color: var(--coral); }
.arc-field { position: absolute; z-index: 3; display: flex; flex-direction: column; align-items: center; width: 137px; padding: 7px 7px 8px; border: 1px solid rgba(208, 211, 229, .85); border-radius: 13px; background: rgba(255, 255, 255, .96); box-shadow: 0 4px 12px rgba(58, 64, 80, .07); }
.arc-field-tt { top: 1px; left: 1%; border-top: 3px solid #7a8fe1; }.arc-field-tu { top: 1px; right: 1%; border-top: 3px solid #e88b75; }.arc-field-ut { bottom: 0; left: 17%; border-top: 3px solid #65ae88; }.arc-field-uu { right: 1%; bottom: 0; border-top: 3px solid #e0ad4b; }
.arc-field-label { color: #778196; font-size: 8px; font-weight: 800; letter-spacing: .02em; text-align: center; text-transform: uppercase; }
.arc-field-formula { margin-top: 2px; color: var(--ink); font-family: Nunito, sans-serif; font-size: 12px; font-weight: 900; }
.arc-practice-area.is-hard-mode .arc-field-label, .arc-practice-area.is-hard-mode .arc-field-formula { visibility: hidden; }
.arc-input, .arc-total-input { border: 2px solid #d8def5; border-radius: 9px; color: var(--blue); background: #fbfcff; font-family: Nunito, sans-serif; font-weight: 900; text-align: center; outline: 0; }
.arc-input { width: 92px; height: 39px; margin-top: 5px; font-size: 23px; }
.arc-input::placeholder, .arc-total-input::placeholder { color: #aeb8d9; opacity: 1; }
.arc-input:focus, .arc-input.is-selected, .arc-total-input:focus, .arc-total-input.is-selected { border-color: var(--blue); outline: 4px solid rgba(81, 116, 216, .14); }
.arc-input.is-correct, .arc-total-input.is-correct { border-color: var(--green); color: #2f8158; background: var(--green-soft); }
.arc-input.is-wrong, .arc-total-input.is-wrong { border-color: var(--coral); color: var(--coral-dark); background: #fff0ec; }
.arc-accessibility-note { margin: 8px 0 0; color: #8a91a1; font-size: 10px; text-align: center; }.arc-accessibility-note span { margin-right: 4px; color: #a05d9d; font-size: 14px; }
.arc-answer-panel { display: grid; gap: 12px; }
.arc-check-card, .arc-total-card { padding: 22px 20px 19px; }
.arc-check-card { background: #fffdf8; }.arc-total-card { background: #f8f9ff; transition: opacity .2s, border .2s; }.arc-total-card[aria-disabled="true"] { opacity: .64; }.arc-total-card.is-enabled { border-color: #bdc9f4; opacity: 1; }
.arc-check-card .section-kicker, .arc-total-card .section-kicker { margin-bottom: 8px; color: #a05d9d; }
.arc-check-card > p:not(.section-kicker), .arc-total-card > p:not(.section-kicker) { margin: 9px 0 15px; color: var(--muted); font-size: 11px; line-height: 1.5; }
.arc-action-button { width: 100%; }
.arc-total-card h3 { color: #465da8; }.arc-sum-preview { margin: 14px 0 7px; color: #6474b9; font-family: Nunito, sans-serif; font-size: 18px; font-weight: 900; letter-spacing: -.02em; text-align: center; }
.arc-total-input { display: block; width: 116px; height: 49px; margin: 0 auto; font-size: 29px; }
.arc-total-hint { min-height: 32px; margin-bottom: 10px !important; text-align: center; }

.geo-exercise-tabs { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin-top: 27px; }
.geo-exercise-tab { display: grid; grid-template-columns: 42px 1fr 20px; align-items: center; gap: 10px; min-height: 73px; padding: 12px 15px; border: 1.5px solid #ece8e0; border-radius: 15px; color: var(--ink); background: #fff; text-align: left; transition: border .2s, background .2s, transform .2s; }
.geo-exercise-tab:hover { transform: translateY(-2px); border-color: #c9d3f2; }
.geo-exercise-tab.is-active { border-color: var(--blue); background: var(--blue-soft); }
.geo-exercise-icon { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 13px; color: #5873c8; background: #e2e8ff; font-family: Nunito, sans-serif; font-size: 24px; font-weight: 900; }
.arrange-exercise-icon { color: #a05d9d; background: #f3def2; }
.geo-exercise-tab strong { display: block; font-size: 14px; }.geo-exercise-tab small { display: block; margin-top: 4px; color: var(--muted); font-size: 10px; font-weight: 500; }.geo-exercise-tab.is-active .tab-check { border-color: var(--blue); color: #fff; background: var(--blue); }
.geo-mode-tabs { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin-top: 13px; }
.geo-mode-tab { display: grid; grid-template-columns: 42px 1fr 20px; align-items: center; gap: 10px; min-height: 73px; padding: 12px 15px; border: 1.5px solid #ece8e0; border-radius: 15px; color: var(--ink); background: #fff; text-align: left; transition: border .2s, background .2s, transform .2s; }
.geo-mode-tab:hover { transform: translateY(-2px); border-color: #c9d3f2; }
.geo-mode-tab.is-active { border-color: var(--green); background: var(--green-soft); }
.geo-tab-icon { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 13px; color: #3f8d61; background: #ccebd6; font-family: Nunito, sans-serif; font-size: 19px; font-weight: 900; }
.hard-tab-icon { color: #5d65b8; background: #e0e1ff; font-size: 22px; }
.geo-mode-tab strong { display: block; font-size: 14px; }.geo-mode-tab small { display: block; margin-top: 4px; color: var(--muted); font-size: 10px; font-weight: 500; }
.geo-mode-tab.is-active .tab-check { border-color: var(--green); color: #fff; background: var(--green); }
.geo-practice-area { display: grid; grid-template-columns: .85fr 1.15fr; gap: 34px; align-items: center; max-width: 850px; margin: 31px auto 27px; }
.geo-question-column { min-width: 0; }.geo-question-box { margin-top: 21px; padding: 28px 18px 24px; border-radius: 21px; background: #f5faf5; text-align: center; }.geo-operation { font-family: Nunito, sans-serif; font-size: clamp(27px, 3vw, 38px); font-weight: 900; letter-spacing: -.035em; }.geo-question-box p { margin: 12px auto 0; color: #819087; font-size: 11px; line-height: 1.45; }.geo-identify-board, .geo-arrange-board { min-width: 0; }.geo-identify-board[hidden], .geo-arrange-board[hidden] { display: none; }
.compass-wrap { display: flex; flex-direction: column; align-items: center; }.compass-rose { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); grid-template-rows: repeat(3, minmax(0, 1fr)); gap: 9px; width: min(100%, 350px); aspect-ratio: 1; padding: 13px; border: 1px solid #e4eee4; border-radius: 50%; background: radial-gradient(circle at center, #fbfdfb 0 23%, #f0f8f0 24% 67%, #e6f2e7 68% 100%); box-shadow: inset 0 0 0 8px rgba(255, 255, 255, .62), 0 9px 20px rgba(64, 112, 76, .08); }
.direction-button { display: flex; flex-direction: column; align-items: center; justify-content: center; min-width: 0; min-height: 0; padding: 5px; border: 1px solid #dfe8df; border-radius: 17px; color: #315743; background: rgba(255, 255, 255, .9); box-shadow: 0 3px 6px rgba(49, 87, 67, .07); font-weight: 800; touch-action: manipulation; transition: transform .15s, border .15s, background .15s, box-shadow .15s; }.direction-button:hover { transform: translateY(-2px); border-color: #79b38b; background: #fff; box-shadow: 0 6px 12px rgba(49, 87, 67, .12); }.direction-button:active { transform: scale(.96); }.direction-button.is-correct { border: 3px solid var(--green); color: #28764b; background: #dff5e5; box-shadow: 0 0 0 4px rgba(98, 174, 135, .18); }.direction-button.is-wrong { border-color: var(--coral); color: #bd5a4c; background: #fff0ec; }
.direction-arrow { font-size: clamp(27px, 4vw, 36px); line-height: .9; }.direction-label { margin-top: 5px; font-family: Nunito, sans-serif; font-size: 12px; font-weight: 900; letter-spacing: .03em; }.compass-rose.is-hard-mode .direction-label { visibility: hidden; }.compass-center { display: grid; grid-area: 2 / 2; place-items: center; width: 64px; height: 64px; align-self: center; justify-self: center; border: 7px solid rgba(255, 255, 255, .8); border-radius: 50%; color: #efaa42; background: var(--yellow); box-shadow: 0 3px 10px rgba(117, 93, 37, .14); font-size: 24px; }
.direction-n { grid-area: 1 / 2; }.direction-ne { grid-area: 1 / 3; }.direction-e { grid-area: 2 / 3; }.direction-se { grid-area: 3 / 3; }.direction-s { grid-area: 3 / 2; }.direction-sw { grid-area: 3 / 1; }.direction-w { grid-area: 2 / 1; }.direction-nw { grid-area: 1 / 1; }.compass-help { margin: 13px 0 0; color: #83928a; font-size: 11px; text-align: center; }
.geo-arrange-board { display: flex; flex-direction: column; align-items: center; gap: 13px; width: 100%; }.geo-arrange-heading { text-align: center; }.geo-arrange-heading .section-kicker { margin-bottom: 7px; color: #a05d9d; }.geo-arrange-heading h3 { margin: 0; font-family: Nunito, sans-serif; font-size: 20px; letter-spacing: -.03em; }.geo-arrange-heading > p:last-child { max-width: 330px; margin: 7px auto 0; color: var(--muted); font-size: 11px; line-height: 1.4; }
.geo-arrange-compass { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); grid-template-rows: repeat(3, minmax(0, 1fr)); gap: 8px; width: min(100%, 350px); aspect-ratio: 1; padding: 13px; border: 1px solid #dce8de; border-radius: 50%; background: radial-gradient(circle at center, #fbfdfb 0 23%, #f0f8f0 24% 67%, #e6f2e7 68% 100%); box-shadow: inset 0 0 0 8px rgba(255, 255, 255, .62), 0 9px 20px rgba(64, 112, 76, .08); }
.direction-slot { display: flex; flex-direction: column; align-items: center; justify-content: center; min-width: 0; min-height: 0; padding: 5px; border: 2px dashed #a8c9b0; border-radius: 16px; color: #4b8060; background: rgba(255, 255, 255, .78); font-weight: 800; touch-action: manipulation; transition: transform .15s, border .15s, background .15s, box-shadow .15s; }.direction-slot:hover, .direction-slot.is-target { transform: translateY(-1px); border-color: var(--blue); background: #f6f8ff; box-shadow: 0 0 0 4px rgba(81, 116, 216, .1); }.direction-slot:active { transform: scale(.97); }.direction-slot.is-filled { border-style: solid; border-color: var(--green); color: #28764b; background: var(--green-soft); box-shadow: 0 0 0 4px rgba(98, 174, 135, .14); }.direction-slot.is-wrong { border-color: var(--coral); color: var(--coral-dark); background: #fff0ec; }.direction-slot-label { font-family: Nunito, sans-serif; font-size: clamp(14px, 2vw, 20px); font-weight: 900; line-height: 1; }.direction-slot-help { margin-top: 4px; color: #87938b; font-size: 8px; font-weight: 700; letter-spacing: .03em; text-transform: uppercase; }.geo-arrange-compass.is-hard-mode .direction-slot-label, .geo-arrange-board.is-hard-mode .direction-tile-label { visibility: hidden; }
.geo-arrange-center { display: grid; grid-area: 2 / 2; place-items: center; width: 58px; height: 58px; align-self: center; justify-self: center; border: 6px solid rgba(255, 255, 255, .8); border-radius: 50%; color: #efaa42; background: var(--yellow); box-shadow: 0 3px 10px rgba(117, 93, 37, .14); font-size: 23px; }.direction-slot-n { grid-area: 1 / 2; }.direction-slot-ne { grid-area: 1 / 3; }.direction-slot-e { grid-area: 2 / 3; }.direction-slot-se { grid-area: 3 / 3; }.direction-slot-s { grid-area: 3 / 2; }.direction-slot-sw { grid-area: 3 / 1; }.direction-slot-w { grid-area: 2 / 1; }.direction-slot-nw { grid-area: 1 / 1; }.direction-slot-arrow { color: #3f8d61; font-size: 27px; line-height: .9; }
.geo-arrange-status { min-height: 18px; margin: 0; color: #6d7d73; font-size: 11px; font-weight: 800; text-align: center; }.direction-tile-bank { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 8px; width: min(100%, 350px); }.direction-tile { display: flex; flex-direction: column; align-items: center; justify-content: center; min-width: 0; min-height: 66px; padding: 6px 4px; border: 1.5px solid #e5e2e9; border-radius: 14px; color: var(--ink); background: #fff; box-shadow: 0 3px 8px rgba(58, 64, 80, .06); cursor: grab; touch-action: none; user-select: none; transition: transform .15s, border .15s, background .15s, opacity .15s, box-shadow .15s; }.direction-tile:hover { transform: translateY(-2px); border-color: #aab9ed; box-shadow: 0 6px 13px rgba(58, 64, 80, .11); }.direction-tile:active { cursor: grabbing; }.direction-tile.is-selected { border-color: var(--blue); background: var(--blue-soft); box-shadow: 0 0 0 4px rgba(81, 116, 216, .12); }.direction-tile.is-dragging { opacity: .25; }.direction-tile[hidden] { display: none; }.direction-tile-arrow { color: #5873c8; font-size: 28px; line-height: .9; }.direction-tile-label { margin-top: 5px; color: #68748e; font-family: Nunito, sans-serif; font-size: 11px; font-weight: 900; }.geo-drag-ghost { position: fixed; z-index: 40; width: 68px; height: 62px; margin: 0; pointer-events: none; opacity: .94; transform: translate(-50%, -50%) rotate(3deg); box-shadow: 0 12px 25px rgba(58, 64, 80, .2); }

.direction-slot-label, .direction-slot-help { display: none; }
.geo-arrange-board.is-hard-mode .direction-tile-arrow { display: none; }
.geo-arrange-board.is-hard-mode .direction-tile-label { visibility: visible; }
.direction-tile { transform: translate(var(--tile-offset-x, 0), var(--tile-offset-y, 0)) rotate(var(--tile-rotation, 0deg)); }
.direction-tile:hover { transform: translate(var(--tile-offset-x, 0), calc(var(--tile-offset-y, 0) - 2px)) rotate(var(--tile-rotation, 0deg)); }

.today-section { padding: 45px 38px 0; }
.calendar-badge { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 11px; color: #7087d8; background: var(--blue-soft); font-size: 18px; }
.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 21px; }
.stat-card { display: flex; align-items: center; gap: 13px; min-height: 79px; padding: 14px 17px; border-radius: 16px; }
.blue-stat { background: var(--blue-soft); }.peach-stat { background: var(--peach); }.green-stat { background: var(--green-soft); }
.stat-icon { display: grid; place-items: center; width: 37px; height: 37px; border-radius: 12px; font-size: 19px; font-weight: 900; }
.blue-stat .stat-icon { color: var(--blue); background: #dbe4ff; }.peach-stat .stat-icon { color: #dc7959; background: #ffd9cc; }.green-stat .stat-icon { color: #3c9566; background: #ccebd6; }
.stat-card strong { display: block; font-family: Nunito, sans-serif; font-size: 26px; line-height: 1; }.stat-card span:not(.stat-icon) { display: block; margin-top: 5px; color: var(--muted); font-size: 11px; font-weight: 600; }
.footer-note { margin: 41px 0 0; color: #9299a5; font-size: 11px; text-align: center; }.footer-note span { margin-right: 5px; color: var(--yellow); font-size: 16px; }

.challenge-status { display: flex; align-items: center; justify-content: center; gap: 18px; width: fit-content; margin: 4px auto -7px; padding: 7px 12px; border: 1px solid #f1e3bd; border-radius: 30px; color: #8d7a51; background: #fff9e9; font-size: 11px; font-weight: 700; }.challenge-status strong { color: #bb7d27; font-family: Nunito, sans-serif; font-size: 14px; }.challenge-status[hidden] { display: none; }

.subject-overlay, .math-setup-overlay, .welcome-overlay, .pause-overlay, .completion-overlay { position: fixed; z-index: 10; inset: 0; display: grid; place-items: center; padding: 20px; background: rgba(39, 47, 64, .32); backdrop-filter: blur(4px); }.subject-overlay[hidden], .math-setup-overlay[hidden], .welcome-overlay[hidden], .pause-overlay[hidden], .completion-overlay[hidden] { display: none; }
.subject-overlay, .session-overlay, .welcome-overlay, .pause-overlay, .completion-overlay { position: fixed; z-index: 10; inset: 0; display: grid; place-items: center; padding: 20px; background: rgba(39, 47, 64, .32); backdrop-filter: blur(4px); }
.subject-overlay[hidden], .math-setup-overlay[hidden], .session-overlay[hidden], .welcome-overlay[hidden], .pause-overlay[hidden], .completion-overlay[hidden] { display: none; }
.subject-card, .math-setup-card, .session-card, .welcome-card, .pause-card, .completion-card { position: relative; width: min(100%, 470px); padding: 44px 42px 38px; border: 1px solid #eae4da; border-radius: 25px; background: var(--paper); box-shadow: 0 24px 70px rgba(35, 42, 59, .2); text-align: center; animation: pop .22s ease-out; }
.subject-card { width: min(100%, 760px); padding-right: 46px; padding-left: 46px; }
.subject-emoji { margin-bottom: 13px; font-size: 44px; }.subject-card h2 { font-size: 33px; }.subject-card > p:not(.section-kicker) { max-width: 335px; margin: 13px auto 22px; color: var(--muted); font-size: 14px; line-height: 1.55; }.subject-options { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; }.subject-option { display: grid; grid-template-columns: 40px 1fr 17px; align-items: center; gap: 9px; min-height: 76px; padding: 10px; border: 1.5px solid #e7e4dd; border-radius: 15px; color: var(--ink); background: #fff; text-align: left; transition: transform .15s, border .15s, background .15s; }.subject-option:hover { transform: translateY(-2px); border-color: #aab9ed; background: #fbfcff; }.subject-option-icon { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px; font-family: Nunito, sans-serif; font-size: 25px; font-weight: 900; }.math-option .subject-option-icon { color: #b74f41; background: #ffd7d1; }.geography-option .subject-option-icon { color: #3d8b60; background: #d8f0dc; font-size: 21px; }.english-option .subject-option-icon { color: #5873c8; background: #e2e8ff; font-size: 22px; }.subject-option strong { display: block; font-size: 13px; }.subject-option small { display: block; margin-top: 4px; color: var(--muted); font-size: 9px; line-height: 1.25; }.subject-arrow { color: #9ba4b2; font-size: 18px; }
.subject-option { grid-template-columns: 46px minmax(0, 1fr) 21px; gap: 11px; min-height: 88px; padding: 12px; }
.subject-option-icon { width: 46px; height: 46px; }
.subject-option strong { font-size: 14px; }
.subject-option small { font-size: 10px; }
.session-card > p:not(.section-kicker) { max-width: 340px; margin: 13px auto 22px; color: var(--muted); font-size: 14px; line-height: 1.55; }.session-emoji { margin-bottom: 13px; font-size: 44px; }.session-card h2 { font-size: 33px; }.session-options { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }.session-option { display: grid; grid-template-columns: 40px 1fr 17px; align-items: center; gap: 9px; min-height: 76px; padding: 10px; border: 1.5px solid #e7e4dd; border-radius: 15px; color: var(--ink); background: #fff; text-align: left; transition: transform .15s, border .15s, background .15s; }.session-option:hover { transform: translateY(-2px); border-color: #e5bf76; background: #fffdf7; }.session-option-icon { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px; background: #fff1cf; font-size: 21px; }.session-option strong { display: block; font-size: 13px; }.session-option small { display: block; margin-top: 4px; color: var(--muted); font-size: 9px; line-height: 1.25; }
.back-button { display: inline-flex; align-items: center; justify-content: center; min-height: 42px; margin-top: 18px; padding: 8px 12px; border: 0; border-radius: 11px; color: #75809a; background: transparent; font-size: 12px; font-weight: 800; transition: color .15s, background .15s; }.back-button:hover { color: var(--blue); background: #f3f6ff; }.back-button[hidden] { display: none; }
.math-setup-card { width: min(100%, 640px); max-height: min(92vh, 760px); overflow-y: auto; }
.math-setup-card > p:not(.section-kicker):not(.flow-choice-hint) { max-width: 430px; margin: 13px auto 18px; color: var(--muted); font-size: 14px; line-height: 1.5; }
.flow-choice-group { margin-top: 16px; text-align: left; }.flow-choice-kicker { margin: 0 0 8px; color: #8b94a4; font-size: 10px; font-weight: 800; letter-spacing: .12em; }.flow-choice-list { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; }.flow-choice { display: grid; grid-template-columns: 39px 1fr 18px; align-items: center; gap: 8px; min-height: 64px; padding: 9px 10px; border: 1.5px solid #ece8e0; border-radius: 14px; color: var(--ink); background: #fff; text-align: left; transition: border .2s, background .2s, transform .2s; }.flow-choice:hover { transform: translateY(-2px); border-color: #c9d3f2; }.flow-choice.is-active { border-color: var(--blue); background: var(--blue-soft); }.flow-method-choice.is-active { border-color: #a66aa1; background: #fcf4fb; }.flow-choice strong { display: block; font-size: 12px; }.flow-choice small { display: block; margin-top: 3px; color: var(--muted); font-size: 9px; line-height: 1.2; }.flow-method-choice.is-active .tab-check { border-color: #a66aa1; color: #fff; background: #a66aa1; }.flow-choice.is-active .tab-check { border-color: var(--blue); color: #fff; background: var(--blue); }.flow-method-choice.is-active .tab-check { border-color: #a66aa1; }.flow-choice[hidden] { display: none; }.flow-choice-hint { margin: 8px 2px 0; color: #8d94a4; font-size: 10px; line-height: 1.35; }.flow-continue-button { width: 100%; margin-top: 21px; }
.welcome-emoji { margin-bottom: 13px; font-size: 44px; }.welcome-card h2 { font-size: 33px; }.welcome-card > p:not(.section-kicker):not(.name-error) { max-width: 335px; margin: 13px auto 22px; color: var(--muted); font-size: 14px; line-height: 1.55; }
.name-label { display: block; margin: 0 0 7px; color: var(--ink); font-size: 11px; font-weight: 800; text-align: left; }.name-input { width: 100%; height: 48px; padding: 0 14px; border: 1.5px solid #dfe4f5; border-radius: 12px; color: var(--ink); background: #fbfcff; font-size: 16px; text-align: left; }.name-input::placeholder { color: #b3bac7; }.name-input:focus { border-color: var(--blue); outline: 4px solid rgba(81, 116, 216, .15); }.name-error { margin: 8px 0 0; color: var(--coral-dark); font-size: 11px; font-weight: 700; text-align: left; }.welcome-card .primary-button { width: 100%; margin-top: 20px; }
.pause-card, .completion-card { position: relative; width: min(100%, 470px); padding: 44px 42px 38px; border: 1px solid #eae4da; border-radius: 25px; background: var(--paper); box-shadow: 0 24px 70px rgba(35, 42, 59, .2); text-align: center; animation: pop .22s ease-out; }
.close-button { position: absolute; top: 15px; right: 17px; width: 31px; height: 31px; border: 0; border-radius: 50%; color: #8690a0; background: #f4f2ee; font-size: 22px; line-height: 1; }.close-button:hover { color: var(--ink); }
.pause-emoji, .completion-emoji { margin-bottom: 15px; font-size: 44px; }.pause-card h2, .completion-card h2 { font-size: 33px; }.pause-card p:not(.section-kicker), .completion-card p:not(.section-kicker) { margin: 14px auto 24px; max-width: 335px; color: var(--muted); font-size: 14px; line-height: 1.55; }
.primary-button, .secondary-button { min-height: 45px; padding: 0 20px; border-radius: 12px; font-size: 13px; font-weight: 800; transition: transform .15s, box-shadow .15s; }.primary-button { border: 0; color: #fff; background: var(--coral); box-shadow: 0 8px 14px rgba(239, 115, 95, .2); }.primary-button:hover { background: var(--coral-dark); transform: translateY(-2px); }.secondary-button { border: 1px solid #e1ddd4; color: var(--ink); background: #fff; }.secondary-button:hover { background: #faf8f4; }
.primary-button.is-success, .secondary-button.is-success { border-color: var(--green); color: #fff; background: var(--green); box-shadow: 0 8px 14px rgba(98, 174, 135, .24); }
.primary-button.is-success:hover, .secondary-button.is-success:hover { background: #4f9b73; }
.primary-button:disabled.is-success, .secondary-button:disabled.is-success { cursor: default; opacity: 1; }
.confetti-layer { position: fixed; z-index: 20; inset: 0; overflow: hidden; pointer-events: none; }
.confetti-piece { position: absolute; top: 0; left: 0; width: 8px; height: 12px; border-radius: 2px; opacity: 0; background: var(--confetti-color); animation: confetti-fountain 1.5s linear forwards; animation-delay: var(--confetti-delay); }
@keyframes confetti-fountain {
  0% { opacity: 0; transform: translate3d(var(--confetti-start-x), var(--confetti-start-y), 0) rotate(0deg) scale(.55); }
  10% { opacity: 1; transform: translate3d(var(--confetti-start-x), var(--confetti-start-y), 0) rotate(35deg) scale(.8); }
  42% { opacity: 1; transform: translate3d(var(--confetti-mid-x), var(--confetti-mid-y), 0) rotate(260deg) scale(1); }
  100% { opacity: 0; transform: translate3d(var(--confetti-end-x), var(--confetti-end-y), 0) rotate(var(--confetti-rotation)) scale(1); }
}
@media (prefers-reduced-motion: reduce) {
  .confetti-piece { animation-duration: .01ms; animation-delay: 0ms; }
}
.confetti { margin-bottom: -5px; color: var(--yellow); font-size: 22px; }.completion-score { display: inline-flex; align-items: center; gap: 9px; margin-bottom: 27px; padding: 9px 14px; border-radius: 12px; background: #f7f4ee; }.completion-score strong { color: var(--blue); font-family: Nunito, sans-serif; font-size: 25px; }.completion-score span { color: var(--muted); font-size: 11px; font-weight: 700; }.completion-actions { display: flex; justify-content: center; gap: 9px; }.completion-actions .primary-button, .completion-actions .secondary-button { flex: 1; }
.challenge-summary { display: grid; grid-template-columns: repeat(3, 1fr); gap: 7px; margin: -11px auto 25px; max-width: 360px; }.challenge-summary[hidden] { display: none; }.challenge-summary > div { padding: 9px 5px; border-radius: 11px; background: #fff8e7; }.challenge-summary strong { display: block; color: #bd7d27; font-family: Nunito, sans-serif; font-size: 20px; }.challenge-summary small { display: block; margin-top: 3px; color: var(--muted); font-size: 9px; font-weight: 700; }
.step-stats { margin: -10px auto 24px; max-width: 390px; }.step-stats[hidden] { display: none; }.step-stats-title { margin: 0 0 8px; color: #8c93a3; font-size: 10px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }.step-stats-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 7px; }.step-stat { padding: 8px 4px 9px; border-radius: 11px; background: #f7f5fb; }.step-stat[hidden] { display: none; }.step-stat strong { display: block; color: #7d6199; font-family: Nunito, sans-serif; font-size: 18px; }.step-stat small { display: block; margin-top: 3px; color: var(--muted); font-size: 8px; font-weight: 700; line-height: 1.2; }
@keyframes pop { from { opacity: 0; transform: translateY(10px) scale(.98); } to { opacity: 1; transform: translateY(0) scale(1); } }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }

@media (max-width: 800px) {
  .app-shell { width: min(100% - 28px, 650px); padding-top: 18px; }
  .hero { grid-template-columns: 1fr; min-height: auto; padding: 44px 12px 30px; }.hero-illustration { height: 190px; margin-top: 20px; transform: scale(.86); }
  .practice-card { padding: 27px 20px 0; border-radius: 22px; }.mode-tabs { grid-template-columns: 1fr; gap: 8px; }.mode-tab { min-height: 63px; grid-template-columns: 39px 1fr 20px; }.tab-icon { width: 39px; height: 39px; }.mode-selector { margin-top: 22px; }.operation-tabs, .method-tabs, .flow-choice-list { grid-template-columns: 1fr; gap: 8px; }.operation-tab, .method-tab { min-height: 63px; grid-template-columns: 39px 1fr 20px; }.math-setup-card { max-height: 90vh; padding: 32px 22px 25px; }.flow-choice { min-height: 60px; }.round-settings { align-items: flex-start; }.round-settings label { flex-direction: column; align-items: flex-start; gap: 2px; }
  .practice-area, .geo-practice-area { grid-template-columns: 1fr; gap: 24px; margin-top: 25px; }.split-practice-area, .english-practice-area { margin-top: 25px; }.question-box { min-height: 190px; }.compass-rose, .geo-arrange-compass { width: min(100%, 335px); }.geo-exercise-tabs { gap: 8px; }.geo-exercise-tab { grid-template-columns: 37px 1fr 18px; gap: 8px; min-height: 66px; padding: 10px; }.geo-exercise-icon { width: 37px; height: 37px; }.geo-exercise-tab strong { font-size: 12px; }.geo-exercise-tab small { font-size: 9px; }.geo-arrange-board { order: 2; }.direction-tile-bank { width: min(100%, 335px); }.english-board { padding: 22px 15px 20px; }.english-word-card { gap: 7px; padding: 15px 10px; }.english-word-label { font-size: 8px; }.english-word { font-size: 28px; }.english-answer-input { height: 48px; font-size: 22px; }.english-rules-panel { padding: 22px 15px 18px; }.english-rules-grid { grid-template-columns: 1fr; }
  .split-board { padding: 22px 15px 18px; }.split-board-heading h3 { font-size: 21px; }.split-main-equation { flex-wrap: wrap; gap: 6px; margin-top: 17px; font-size: clamp(30px, 8.5vw, 40px); }.split-product-answer { flex-basis: 100%; justify-content: center; gap: 5px; }.split-product-input { width: 74px; height: 44px; font-size: 22px; }.split-final-answer { flex-basis: 100%; justify-content: center; text-align: center; }.split-final-input { width: 74px; height: 44px; font-size: 22px; }.split-balloon { padding: 18px 13px 20px; }.split-decomposition { gap: 9px; }.split-decomposition-input { width: 96px; height: 48px; font-size: 25px; }.split-decomposition.is-many { width: 100%; max-width: 100%; gap: 3px; }.split-decomposition.is-many .split-decomposition-input { width: 100%; height: 45px; font-size: 22px; }.split-decomposition.is-many .split-part-field > span { min-width: 0; font-size: 7px; letter-spacing: .03em; }
  .arc-workspace { grid-template-columns: 1fr; gap: 18px; }.arc-board { padding: 20px 15px 14px; }
  .arc-canvas { display: block; height: 390px; min-height: 390px; overflow: hidden; }
  .arc-lines { top: 0; right: 0; bottom: 0; left: 0; width: 100%; height: 100%; }
  .arc-equation { position: absolute; top: 164px; right: 5%; left: 5%; min-height: 0; }
  .arc-field { position: absolute; width: calc(50% - 8px); min-height: 112px; }
  .arc-field-tt { top: 0; right: auto; bottom: auto; left: 0; }
  .arc-field-tu { top: 0; right: 0; bottom: auto; left: auto; }
  .arc-field-ut { top: auto; right: auto; bottom: 0; left: 0; }
  .arc-field-uu { top: auto; right: 0; bottom: 0; left: auto; }
  .tip-strip { margin: 0 -20px; padding: 15px 20px; }.today-section { padding: 36px 0 0; }.stats-grid { grid-template-columns: 1fr; gap: 9px; }.stat-card { min-height: 67px; }.footer-note { margin-top: 31px; }
}

@media (max-width: 430px) {
  .session-note { display: none; }.session-button, .subject-button { padding-right: 4px; }.session-button #sessionName, .subject-button #subjectName { max-width: 74px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }.name-button { padding-right: 4px; }.name-button #headerName { max-width: 70px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }.hero { padding-top: 38px; }.hero-illustration { margin-left: -7px; }.hero-copy > p { font-size: 14px; }.practice-header h2 { font-size: 25px; }.round-settings label small { display: none; }.subject-options, .session-options { grid-template-columns: 1fr; }.subject-card, .session-card, .completion-card, .pause-card, .welcome-card { padding: 36px 22px 27px; }.challenge-status { gap: 10px; font-size: 10px; }.challenge-status strong { font-size: 12px; }.completion-actions { flex-direction: column-reverse; }.completion-actions button { width: 100%; }.back-button { width: 100%; }.arc-mode-tabs { grid-template-columns: 1fr; margin-bottom: 18px; }.arc-board-heading h3 { font-size: 18px; }.arc-canvas { height: 390px; min-height: 390px; }.arc-field { width: calc(50% - 8px); min-height: 112px; padding-left: 4px; padding-right: 4px; }.arc-field-label { font-size: 7px; }.arc-field-formula { font-size: 11px; }.arc-input { width: 84px; height: 37px; font-size: 21px; }.split-board { padding-left: 10px; padding-right: 10px; }.split-board-heading h3 { font-size: 19px; }.split-main-equation { gap: 4px; font-size: clamp(29px, 8vw, 35px); }.split-product-answer { gap: 4px; }.split-product-input { width: 69px; height: 42px; font-size: 20px; }.split-balloon { border-radius: 23px; }.split-balloon-title { font-size: 12px; }.split-balloon-title strong { font-size: 19px; }.split-decomposition-input { width: 86px; height: 45px; font-size: 23px; }.split-decomposition.is-many .split-decomposition-input { width: 100%; height: 42px; font-size: 20px; }.split-decomposition.is-many .split-part-field > span { min-width: 0; font-size: 6.5px; letter-spacing: .01em; }.split-part-field { font-size: 8px; }
}

@media (hover: none) {
  .direction-button:hover { transform: none; box-shadow: 0 2px 3px rgba(40, 52, 73, .025); }
  .direction-button:active { transform: none; }
}

@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; transition-duration: .01ms !important; } }

@media (max-width: 430px) {
  .arc-range-control { margin-top: -8px; padding-right: 10px; padding-left: 10px; }
  .arc-range-option { padding-right: 8px; padding-left: 8px; }
  .split-answer-panel { margin-top: 17px; margin-right: 0; margin-left: 0; padding: 15px 10px 16px; }
  .split-product-grid { grid-template-columns: 1fr; gap: 7px; }
  .split-product-item { justify-content: space-between; padding: 7px 8px; }
  .split-product-formula, .split-total-formula { font-size: 15px; }
  .split-products-plus { line-height: .8; }
  .split-final-answer { flex-wrap: wrap; gap: 6px; }
}