:root {
  color-scheme: light;
  --ink: #17233d;
  --ink-soft: #5f6980;
  --navy: #17233d;
  --navy-2: #22345b;
  --accent: #f3a63b;
  --accent-soft: #fff0d8;
  --mint: #3aa98f;
  --mint-soft: #dff4ed;
  --blue: #5374c7;
  --blue-soft: #e7ecfb;
  --danger: #c9505c;
  --danger-soft: #fde8eb;
  --surface: #ffffff;
  --surface-2: #f7f8fb;
  --surface-3: #eef1f7;
  --border: #dfe4ee;
  --shadow: 0 18px 55px rgba(25, 36, 62, 0.09);
  --shadow-soft: 0 8px 28px rgba(25, 36, 62, 0.07);
  --radius-xl: 28px;
  --radius-lg: 20px;
  --radius-md: 14px;
  --sidebar: 260px;
  font-family: 'DM Sans', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

:root[data-theme='dark'] {
  color-scheme: dark;
  --ink: #f1f4fb;
  --ink-soft: #aab4c9;
  --navy: #10192c;
  --navy-2: #1b2a49;
  --accent: #ffb84e;
  --accent-soft: #3a2e1f;
  --mint: #64c8ad;
  --mint-soft: #173a35;
  --blue: #8ba8f1;
  --blue-soft: #222f50;
  --danger: #f17b86;
  --danger-soft: #40242a;
  --surface: #172238;
  --surface-2: #111a2c;
  --surface-3: #22304a;
  --border: #2c3b57;
  --shadow: 0 18px 55px rgba(0, 0, 0, 0.28);
  --shadow-soft: 0 8px 28px rgba(0, 0, 0, 0.2);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  background: var(--surface-2);
  color: var(--ink);
  line-height: 1.55;
}

button, input, select { font: inherit; }
button { color: inherit; }
button:focus-visible, input:focus-visible, select:focus-visible, [tabindex]:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent), transparent 45%);
  outline-offset: 2px;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 10px;
  left: 10px;
  transform: translateY(-150%);
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--surface);
  color: var(--ink);
}
.skip-link:focus { transform: none; }

.app-shell {
  display: grid;
  grid-template-columns: var(--sidebar) minmax(0, 1fr);
  grid-template-rows: 78px minmax(calc(100vh - 78px), auto);
  min-height: 100vh;
}

.sidebar {
  position: fixed;
  z-index: 40;
  inset: 0 auto 0 0;
  width: var(--sidebar);
  display: flex;
  flex-direction: column;
  padding: 26px 20px 22px;
  background:
    radial-gradient(circle at 25% 92%, rgba(243, 166, 59, 0.13), transparent 28%),
    linear-gradient(165deg, var(--navy-2), var(--navy));
  color: #f6f8fd;
}

.brand { display: flex; align-items: center; gap: 12px; margin: 0 8px 34px; }
.brand-mark {
  display: grid;
  width: 45px;
  height: 45px;
  place-items: center;
  border-radius: 14px;
  background: linear-gradient(140deg, #ffc562, #ef9657);
  color: #17233d;
  font-weight: 800;
  letter-spacing: -0.04em;
  box-shadow: 0 10px 25px rgba(243, 166, 59, 0.24);
}
.brand strong { display: block; font-size: 1.02rem; }
.brand span { display: block; color: #aeb9ce; font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.1em; }

.nav-list { display: grid; gap: 7px; }
.nav-item {
  display: flex;
  align-items: center;
  gap: 13px;
  width: 100%;
  min-height: 47px;
  padding: 0 14px;
  border: 0;
  border-radius: 13px;
  background: transparent;
  color: #bfc8d9;
  text-align: left;
  cursor: pointer;
  transition: 160ms ease;
}
.nav-item > span:first-child { width: 25px; font-size: 1.04rem; font-weight: 700; text-align: center; }
.nav-item:hover { background: rgba(255,255,255,0.07); color: #fff; }
.nav-item.is-active { background: rgba(255,255,255,0.12); color: #fff; box-shadow: inset 3px 0 var(--accent); }

.sidebar-card { margin-top: auto; padding: 16px; border: 1px solid rgba(255,255,255,0.1); border-radius: 17px; background: rgba(255,255,255,0.06); }
.sidebar-card-top { display: flex; justify-content: space-between; gap: 10px; font-size: 0.83rem; }
.sidebar-card-top strong { color: var(--accent); }
.sidebar-card small { display: block; margin-top: 10px; color: #aeb9ce; line-height: 1.45; }
.progress-track { height: 7px; margin-top: 10px; overflow: hidden; border-radius: 20px; background: rgba(255,255,255,0.12); }
.progress-track span { display: block; width: 0; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--accent), #ffd280); transition: width 300ms ease; }
.sidebar-source { margin: 18px 4px 0; color: #8996ad; font-size: 0.68rem; line-height: 1.45; }

.topbar {
  position: sticky;
  z-index: 30;
  top: 0;
  grid-column: 2;
  grid-row: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(22px, 4vw, 54px);
  border-bottom: 1px solid color-mix(in srgb, var(--border), transparent 25%);
  background: color-mix(in srgb, var(--surface-2), transparent 8%);
  backdrop-filter: blur(16px);
}
.topbar-title span { display: block; color: var(--ink-soft); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.12em; }
.topbar-title strong { display: block; font-size: 1.1rem; }
.topbar-actions { display: flex; align-items: center; gap: 9px; }
.icon-button, .secondary-button, .primary-button, .ghost-button {
  border: 0;
  cursor: pointer;
  transition: transform 150ms ease, background 150ms ease, border-color 150ms ease;
}
.icon-button:hover, .secondary-button:hover, .primary-button:hover, .ghost-button:hover { transform: translateY(-1px); }
.icon-button { display: grid; width: 42px; height: 42px; place-items: center; border: 1px solid var(--border); border-radius: 13px; background: var(--surface); }
.secondary-button, .primary-button, .ghost-button { min-height: 42px; padding: 0 16px; border-radius: 12px; font-weight: 700; }
.secondary-button { border: 1px solid var(--border); background: var(--surface); }
.primary-button { background: var(--ink); color: var(--surface); box-shadow: var(--shadow-soft); }
:root[data-theme='dark'] .primary-button { background: var(--accent); color: #19233a; }
.ghost-button { background: var(--surface-3); }
.mobile-menu { display: none; }

main { grid-column: 2; grid-row: 2; min-width: 0; }
.view { display: none; width: min(1450px, 100%); margin: 0 auto; padding: 34px clamp(22px, 4vw, 54px) 80px; }
.view.is-visible { display: block; animation: fade-in 180ms ease; }
@keyframes fade-in { from { opacity: 0; transform: translateY(4px); } }

.page-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; margin-bottom: 25px; }
.page-heading h1, .hero h1 { margin: 0; font-family: 'Fraunces', Georgia, serif; line-height: 1.08; letter-spacing: -0.035em; }
.page-heading h1 { font-size: clamp(2rem, 3.8vw, 3rem); }
.page-heading p { max-width: 700px; margin: 9px 0 0; color: var(--ink-soft); }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; margin-bottom: 8px; color: var(--blue); font-size: 0.75rem; font-weight: 800; text-transform: uppercase; letter-spacing: 0.1em; }
.eyebrow::before { content: ''; width: 20px; height: 2px; background: currentColor; }

.hero {
  position: relative;
  overflow: hidden;
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(250px, 0.6fr);
  min-height: 280px;
  padding: clamp(28px, 5vw, 56px);
  border-radius: var(--radius-xl);
  background:
    radial-gradient(circle at 88% 18%, rgba(255, 193, 91, 0.28), transparent 25%),
    radial-gradient(circle at 72% 92%, rgba(94, 187, 164, 0.19), transparent 25%),
    linear-gradient(145deg, #1d2c4c, #131d32);
  color: #fff;
  box-shadow: var(--shadow);
}
.hero::after { content: '∑'; position: absolute; right: 7%; bottom: -32%; color: rgba(255,255,255,0.035); font: 400 320px/1 Georgia, serif; }
.hero-content { position: relative; z-index: 1; }
.hero .eyebrow { color: #ffc45e; }
.hero h1 { max-width: 670px; font-size: clamp(2.35rem, 5vw, 4.3rem); }
.hero p { max-width: 640px; margin: 18px 0 26px; color: #c5cede; font-size: 1.02rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.hero .primary-button { background: var(--accent); color: #17233d; }
.hero .ghost-button { background: rgba(255,255,255,.1); color: #fff; }
.hero-visual { position: relative; z-index: 1; display: grid; align-content: center; gap: 10px; }
.hero-mini-card { display: grid; grid-template-columns: 48px 1fr; gap: 12px; align-items: center; padding: 15px; border: 1px solid rgba(255,255,255,.11); border-radius: 16px; background: rgba(255,255,255,.07); backdrop-filter: blur(12px); }
.hero-mini-card:nth-child(2) { transform: translateX(22px); }
.hero-mini-card strong { display: block; font-size: 1.25rem; }
.hero-mini-card span { color: #bfc8d9; font-size: 0.78rem; }
.hero-mini-icon { display: grid; width: 48px; height: 48px; place-items: center; border-radius: 14px; background: rgba(243,166,59,.17); color: #ffc45e; font-size: 1.15rem; font-weight: 800; }

.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 15px; margin: 20px 0; }
.stat-card { position: relative; overflow: hidden; padding: 21px; border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--surface); box-shadow: var(--shadow-soft); }
.stat-card::after { content: ''; position: absolute; width: 66px; height: 66px; right: -20px; top: -20px; border-radius: 50%; background: var(--card-tint, var(--blue-soft)); }
.stat-label { color: var(--ink-soft); font-size: 0.78rem; font-weight: 700; text-transform: uppercase; letter-spacing: .07em; }
.stat-value { display: block; margin-top: 5px; font: 650 clamp(1.8rem, 3vw, 2.6rem)/1.1 'Fraunces', serif; }
.stat-card small { display: block; margin-top: 7px; color: var(--ink-soft); }

.dashboard-grid { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(300px, .65fr); gap: 20px; }
.panel { padding: 24px; border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--surface); box-shadow: var(--shadow-soft); }
.panel-head { display: flex; justify-content: space-between; align-items: center; gap: 15px; margin-bottom: 18px; }
.panel-head h2, .panel-head h3 { margin: 0; font-size: 1.05rem; }
.panel-head p { margin: 4px 0 0; color: var(--ink-soft); font-size: .84rem; }

.plan-progress-list { display: grid; gap: 16px; }
.plan-progress-row { display: grid; grid-template-columns: minmax(170px, 1fr) minmax(130px, 1.3fr) 45px; gap: 14px; align-items: center; }
.plan-progress-row strong { font-size: .88rem; }
.plan-progress-row small { color: var(--ink-soft); text-align: right; }
.light-track { height: 8px; overflow: hidden; border-radius: 20px; background: var(--surface-3); }
.light-track span { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--blue), #93a8dc); }

.continue-card { padding: 22px; border-radius: 18px; background: linear-gradient(145deg, var(--accent-soft), color-mix(in srgb, var(--surface), var(--accent-soft) 30%)); }
.continue-card .tag { margin-bottom: 10px; }
.continue-card h3 { margin: 0; font-size: 1.15rem; }
.continue-card p { margin: 8px 0 17px; color: var(--ink-soft); font-size: .9rem; }

.tag { display: inline-flex; align-items: center; min-height: 27px; padding: 0 10px; border-radius: 999px; background: var(--blue-soft); color: var(--blue); font-size: .7rem; font-weight: 800; text-transform: uppercase; letter-spacing: .06em; }
.tag.is-essential { background: var(--accent-soft); color: color-mix(in srgb, var(--accent), #6b3e00 48%); }
.tag.is-success { background: var(--mint-soft); color: var(--mint); }
.tag.is-danger { background: var(--danger-soft); color: var(--danger); }

.control-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.search-field { position: relative; flex: 1; min-width: 220px; }
.search-field input { width: 100%; height: 44px; padding: 0 14px 0 42px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); color: var(--ink); }
.search-field::before { content: '⌕'; position: absolute; z-index: 1; left: 15px; top: 9px; color: var(--ink-soft); font-size: 1.1rem; }
.select-field { height: 44px; min-width: 170px; padding: 0 38px 0 13px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); color: var(--ink); }

.course-layout { display: grid; grid-template-columns: minmax(255px, 0.36fr) minmax(0, 1fr); gap: 20px; align-items: start; }
.course-catalog { position: sticky; top: 100px; max-height: calc(100vh - 130px); overflow: auto; padding: 14px; scrollbar-width: thin; }
.catalog-summary { display: flex; justify-content: space-between; align-items: center; padding: 5px 5px 15px; border-bottom: 1px solid var(--border); }
.catalog-summary strong { font-size: .88rem; }
.catalog-summary span { color: var(--ink-soft); font-size: .75rem; }
.catalog-part { margin-top: 12px; }
.catalog-part-title { width: 100%; padding: 11px 10px; border: 0; border-radius: 10px; background: var(--surface-3); text-align: left; font-weight: 800; cursor: pointer; }
.catalog-section-title { margin: 13px 8px 6px; color: var(--ink-soft); font-size: .72rem; font-weight: 800; text-transform: uppercase; letter-spacing: .04em; }
.catalog-topic { width: 100%; padding: 9px 10px; border: 0; border-left: 2px solid var(--border); background: transparent; color: var(--ink-soft); text-align: left; font-size: .81rem; cursor: pointer; }
.catalog-topic:hover { color: var(--ink); background: var(--surface-2); }
.catalog-topic.is-active { border-left-color: var(--accent); background: var(--accent-soft); color: var(--ink); font-weight: 700; }

.course-reader { min-width: 0; }
.reader-header { padding: clamp(22px, 4vw, 34px); }
.reader-breadcrumb { color: var(--ink-soft); font-size: .76rem; }
.reader-header h2 { margin: 9px 0 10px; font: 650 clamp(1.65rem, 3vw, 2.5rem)/1.15 'Fraunces', serif; }
.reader-header p { margin: 0; color: var(--ink-soft); }
.audio-player { display: grid; grid-template-columns: auto minmax(150px, 1fr) auto; gap: 12px; align-items: center; margin-top: 22px; padding: 14px; border-radius: 15px; background: var(--surface-2); }
.audio-buttons { display: flex; gap: 6px; }
.audio-buttons button { width: 38px; height: 38px; border: 0; border-radius: 11px; background: var(--surface); cursor: pointer; }
.audio-options { display: flex; gap: 8px; }
.audio-options select { min-width: 0; max-width: 230px; height: 36px; border: 1px solid var(--border); border-radius: 9px; background: var(--surface); font-size: .78rem; }
.audio-status { color: var(--ink-soft); font-size: .75rem; text-align: right; }

.lesson-card { margin-top: 16px; padding: clamp(22px, 4vw, 36px); }
.lesson-card-head { display: flex; justify-content: space-between; gap: 20px; align-items: flex-start; padding-bottom: 18px; border-bottom: 1px solid var(--border); }
.lesson-card h3 { max-width: 800px; margin: 7px 0 0; font: 650 clamp(1.25rem, 2.5vw, 1.75rem)/1.25 'Fraunces', serif; }
.complete-button { white-space: nowrap; }
.lesson-content { margin-top: 23px; color: color-mix(in srgb, var(--ink), var(--ink-soft) 15%); font-family: Georgia, 'Times New Roman', serif; font-size: 1.02rem; line-height: 1.8; white-space: pre-line; }
.lesson-content::first-line { color: var(--ink); }
.lesson-navigation { display: flex; justify-content: space-between; gap: 12px; margin-top: 18px; }

.formula-toolbar, .glossary-toolbar { margin-bottom: 20px; }
.formula-count-banner { display: flex; align-items: center; gap: 20px; margin-bottom: 20px; padding: 20px 24px; border: 1px solid color-mix(in srgb, var(--accent), var(--border) 55%); border-radius: var(--radius-lg); background: var(--accent-soft); }
.formula-count-banner strong { font: 650 2.5rem/1 'Fraunces', serif; }
.formula-count-banner p { margin: 0; color: var(--ink-soft); }
.formula-count-banner b { color: var(--ink); }
.formula-tabs { display: inline-flex; max-width: 100%; margin-bottom: 20px; padding: 4px; border: 1px solid var(--border); border-radius: 14px; background: var(--surface-3); }
.formula-tab { min-height: 41px; padding: 0 16px; border: 0; border-radius: 10px; background: transparent; color: var(--ink-soft); font-weight: 750; cursor: pointer; }
.formula-tab.is-active { background: var(--surface); color: var(--ink); box-shadow: var(--shadow-soft); }
.formula-groups { display: grid; gap: 24px; }
.formula-group-head { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.formula-group-head h2 { margin: 0; font-size: 1.1rem; }
.formula-group-head span { display: grid; min-width: 31px; height: 31px; padding: 0 8px; place-items: center; border-radius: 9px; background: var(--surface-3); color: var(--ink-soft); font-size: .75rem; font-weight: 800; }
.formula-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.formula-card { padding: 21px; border: 1px solid var(--border); border-radius: 17px; background: var(--surface); box-shadow: var(--shadow-soft); }
.formula-card-top { display: flex; justify-content: space-between; gap: 10px; }
.formula-card h3 { margin: 0; font-size: .95rem; }
.formula-expression { margin-top: 15px; padding: 15px; overflow-wrap: anywhere; border-radius: 12px; background: var(--surface-2); color: var(--ink); font: 600 1rem/1.6 'DM Sans', sans-serif; }
.formula-detail-label { display: block; margin-top: 15px; color: var(--blue); font-size: .7rem; font-weight: 800; text-transform: uppercase; letter-spacing: .08em; }
.formula-detail .formula-expression { margin-top: 6px; }
.formula-expression.is-expanded { border-left: 4px solid var(--accent); font-size: .95rem; }
.formula-terms { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 12px; }
.formula-terms span { padding: 6px 9px; border-radius: 999px; background: var(--blue-soft); color: var(--blue); font-size: .72rem; font-weight: 700; }
.formula-detail p { margin: 13px 2px 0; color: var(--ink-soft); font-size: .85rem; line-height: 1.65; }
.formula-path { margin-top: 12px; color: var(--ink-soft); font-size: .72rem; }

.glossary-layout { display: grid; grid-template-columns: minmax(0, .9fr) minmax(310px, .62fr); gap: 20px; align-items: start; }
.flashcard-panel { position: sticky; top: 100px; }
.flashcard-meta { display: flex; justify-content: space-between; color: var(--ink-soft); font-size: .8rem; }
.flashcard { width: 100%; min-height: 330px; margin-top: 14px; padding: 0; border: 0; background: transparent; perspective: 1000px; cursor: pointer; }
.flashcard-inner { position: relative; display: block; width: 100%; min-height: 330px; transition: transform 430ms cubic-bezier(.2,.7,.2,1); transform-style: preserve-3d; }
.flashcard.is-flipped .flashcard-inner { transform: rotateY(180deg); }
.flashcard-face { position: absolute; inset: 0; display: grid; align-content: center; justify-items: center; padding: clamp(28px, 5vw, 52px); border: 1px solid var(--border); border-radius: 24px; background: var(--surface); box-shadow: var(--shadow); backface-visibility: hidden; }
.flashcard-face.is-back { transform: rotateY(180deg); background: linear-gradient(145deg, var(--navy-2), var(--navy)); color: #fff; }
.flashcard-face small { color: var(--ink-soft); text-transform: uppercase; letter-spacing: .1em; }
.flashcard-face.is-back small { color: #b8c2d6; }
.flashcard-face h2 { max-width: 620px; margin: 20px 0; font: 650 clamp(1.8rem, 4vw, 3rem)/1.2 'Fraunces', serif; text-align: center; }
.flashcard-face p { max-width: 680px; margin: 20px 0; color: #ecf0f8; font-size: 1.03rem; text-align: center; }
.flashcard-controls { display: grid; grid-template-columns: 1fr auto auto 1fr; gap: 8px; margin-top: 14px; }
.flashcard-controls button:first-child { justify-self: start; }
.flashcard-controls button:last-child { justify-self: end; }

.glossary-results { min-height: 500px; }
.definition-list { display: grid; gap: 9px; max-height: 760px; overflow: auto; padding-right: 5px; scrollbar-width: thin; }
.definition-row { padding: 14px 15px; border: 1px solid var(--border); border-radius: 13px; background: var(--surface); cursor: pointer; }
.definition-row:hover { border-color: var(--blue); }
.definition-row.is-active { border-color: var(--accent); background: var(--accent-soft); }
.definition-row strong { display: block; font-size: .88rem; }
.definition-row p { display: -webkit-box; margin: 5px 0 0; overflow: hidden; color: var(--ink-soft); font-size: .78rem; -webkit-box-orient: vertical; -webkit-line-clamp: 2; }

.training-setup { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 13px; }
.mode-card { position: relative; min-height: 150px; padding: 20px; border: 1px solid var(--border); border-radius: 18px; background: var(--surface); text-align: left; cursor: pointer; transition: 160ms ease; }
.mode-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-soft); }
.mode-card.is-selected { border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent), transparent 76%); }
.mode-icon { display: grid; width: 40px; height: 40px; place-items: center; margin-bottom: 15px; border-radius: 12px; background: var(--blue-soft); color: var(--blue); font-weight: 800; }
.mode-card h3 { margin: 0; font-size: .95rem; }
.mode-card p { margin: 6px 0 0; color: var(--ink-soft); font-size: .78rem; }
.training-options { display: flex; flex-wrap: wrap; align-items: end; gap: 12px; margin-top: 18px; padding: 18px; border-radius: 17px; background: var(--surface); border: 1px solid var(--border); }
.field-group { display: grid; gap: 6px; }
.field-group label { color: var(--ink-soft); font-size: .74rem; font-weight: 700; }
.field-group select { height: 42px; min-width: 155px; padding: 0 12px; border: 1px solid var(--border); border-radius: 11px; background: var(--surface-2); color: var(--ink); }
.training-options .primary-button { margin-left: auto; }

.quiz-shell { max-width: 900px; margin: 0 auto; }
.quiz-top { display: grid; grid-template-columns: auto 1fr auto; gap: 14px; align-items: center; margin-bottom: 18px; }
.quiz-top strong { font-size: .82rem; }
.quiz-top span { color: var(--ink-soft); font-size: .8rem; }
.quiz-card { padding: clamp(24px, 5vw, 44px); }
.quiz-label { color: var(--blue); font-size: .73rem; font-weight: 800; text-transform: uppercase; letter-spacing: .1em; }
.quiz-question { margin: 13px 0 24px; font: 650 clamp(1.35rem, 3vw, 2rem)/1.35 'Fraunces', serif; }
.quiz-question.is-definition { font-family: 'DM Sans', sans-serif; font-size: clamp(1.05rem, 2.3vw, 1.35rem); font-weight: 600; }
.answer-grid { display: grid; gap: 10px; }
.answer-option { width: 100%; padding: 15px 17px; border: 1px solid var(--border); border-radius: 13px; background: var(--surface-2); text-align: left; cursor: pointer; }
.answer-option:hover:not(:disabled) { border-color: var(--blue); background: var(--blue-soft); }
.answer-option.is-correct { border-color: var(--mint); background: var(--mint-soft); }
.answer-option.is-wrong { border-color: var(--danger); background: var(--danger-soft); }
.feedback-box { display: none; margin-top: 17px; padding: 16px; border-radius: 13px; }
.feedback-box.is-visible { display: block; }
.feedback-box.is-correct { background: var(--mint-soft); }
.feedback-box.is-wrong { background: var(--danger-soft); }
.feedback-box strong { display: block; }
.feedback-box p { margin: 5px 0 0; }
.quiz-actions { display: flex; justify-content: flex-end; gap: 9px; margin-top: 18px; }

.cloze-text { padding: 22px; border-radius: 16px; background: var(--surface-2); font-size: 1.07rem; line-height: 2.1; }
.blank-slot { display: inline-flex; min-width: 100px; min-height: 36px; padding: 2px 10px; align-items: center; justify-content: center; border: 2px dashed var(--blue); border-radius: 9px; color: var(--blue); font-size: .87rem; font-weight: 700; vertical-align: middle; }
.blank-slot.is-filled { border-style: solid; background: var(--blue-soft); }
.blank-slot.is-correct { border-color: var(--mint); background: var(--mint-soft); color: var(--mint); }
.blank-slot.is-wrong { border-color: var(--danger); background: var(--danger-soft); color: var(--danger); }
.blank-input { width: clamp(120px, 28vw, 230px); min-height: 38px; padding: 4px 10px; border: 2px solid var(--blue); border-radius: 9px; background: var(--surface); color: var(--ink); font-size: .87rem; font-weight: 700; vertical-align: middle; }
.blank-input.is-correct { border-color: var(--mint); background: var(--mint-soft); color: var(--mint); }
.blank-input.is-wrong { border-color: var(--danger); background: var(--danger-soft); color: var(--danger); }
.cloze-free-hint { margin: 13px 2px 0; color: var(--ink-soft); font-size: .8rem; }
.word-bank { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 17px; }
.word-chip { padding: 9px 13px; border: 1px solid var(--border); border-radius: 999px; background: var(--surface); cursor: pointer; }
.word-chip:hover:not(:disabled) { border-color: var(--blue); }
.word-chip:disabled { opacity: .42; cursor: not-allowed; }

.recall-card { display: grid; }
.recall-input, .recall-textarea { width: 100%; padding: 14px 16px; border: 1px solid var(--border); border-radius: 13px; background: var(--surface-2); color: var(--ink); line-height: 1.6; resize: vertical; }
.recall-input { min-height: 48px; }
.recall-textarea { min-height: 180px; }
.dictation-controls { display: flex; align-items: center; gap: 12px; margin-bottom: 13px; padding: 13px; border-radius: 13px; background: var(--blue-soft); }
.dictation-controls span { color: var(--ink-soft); font-size: .78rem; }

.empty-state { padding: 50px 24px; color: var(--ink-soft); text-align: center; }
.empty-state strong { display: block; color: var(--ink); font-size: 1.1rem; }
.results-card { max-width: 640px; margin: 40px auto; padding: 42px; text-align: center; }
.results-score { display: grid; width: 130px; height: 130px; margin: 0 auto 22px; place-items: center; border-radius: 50%; background: var(--mint-soft); color: var(--mint); font: 650 2.5rem/1 'Fraunces', serif; }
.results-card h2 { font: 650 2rem/1.2 'Fraunces', serif; }
.results-card p { color: var(--ink-soft); }

.mobile-nav { display: none; }
.field-label { font-weight: 700; }
.automatic-question-count { display: flex; align-items: baseline; gap: 9px; min-height: 44px; padding: 9px 12px; border: 1px solid var(--border); border-radius: 11px; background: var(--surface); }
.automatic-question-count strong { color: var(--accent); font-size: 1.35rem; line-height: 1; }
.automatic-question-count span { color: var(--ink-soft); }
.field-group small { color: var(--ink-soft); font-size: .78rem; }
.toast-region { position: fixed; z-index: 100; right: 20px; bottom: 20px; display: grid; gap: 8px; }
.toast { max-width: 360px; padding: 13px 16px; border: 1px solid var(--border); border-radius: 13px; background: var(--surface); box-shadow: var(--shadow); animation: toast-in 200ms ease; }
@keyframes toast-in { from { transform: translateY(8px); opacity: 0; } }

@media (max-width: 1050px) {
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .dashboard-grid { grid-template-columns: 1fr; }
  .formula-grid { grid-template-columns: 1fr; }
  .training-setup { grid-template-columns: repeat(2, 1fr); }
  .glossary-layout { grid-template-columns: 1fr; }
  .flashcard-panel { position: static; }
  .definition-list { max-height: 500px; }
}

@media (max-width: 800px) {
  .app-shell { display: block; padding-bottom: 72px; }
  .sidebar { transform: translateX(-105%); transition: transform 220ms ease; box-shadow: 25px 0 70px rgba(0,0,0,.26); }
  .sidebar { visibility: hidden; pointer-events: none; }
  .sidebar.is-open { visibility: visible; pointer-events: auto; transform: none; }
  .topbar { position: sticky; height: 68px; padding: 0 16px; }
  .mobile-menu { display: grid; }
  .topbar-title { flex: 1; margin-left: 12px; }
  .topbar-title span { display: none; }
  .topbar-title strong { font-size: .95rem; }
  .install-button { display: none !important; }
  main { min-height: calc(100vh - 68px); }
  .view { padding: 24px 16px 36px; }
  .mobile-nav { position: fixed; z-index: 35; inset: auto 0 0; display: grid; grid-template-columns: repeat(5, 1fr); padding: 7px 5px calc(7px + env(safe-area-inset-bottom)); border-top: 1px solid var(--border); background: color-mix(in srgb, var(--surface), transparent 3%); backdrop-filter: blur(16px); }
  .mobile-nav button { display: grid; justify-items: center; gap: 1px; padding: 3px 0; border: 0; background: transparent; color: var(--ink-soft); }
  .mobile-nav button span { font-weight: 800; }
  .mobile-nav button small { font-size: .62rem; }
  .mobile-nav button.is-active { color: var(--accent); }
  .hero { grid-template-columns: 1fr; padding: 32px 26px; }
  .hero-visual { display: none; }
  .page-heading { display: block; }
  .page-heading .control-row { margin-top: 16px; }
  .course-layout { grid-template-columns: 1fr; }
  .course-catalog { position: static; max-height: 370px; }
  .audio-player { grid-template-columns: auto 1fr; }
  .audio-options { grid-column: 1 / -1; }
  .audio-status { text-align: left; }
}

@media (max-width: 560px) {
  .stats-grid { grid-template-columns: 1fr 1fr; gap: 9px; }
  .stat-card { padding: 16px; }
  .stat-value { font-size: 1.85rem; }
  .plan-progress-row { grid-template-columns: 1fr auto; }
  .plan-progress-row .light-track { grid-column: 1 / -1; grid-row: 2; }
  .plan-progress-row small { grid-column: 2; grid-row: 1; }
  .training-setup { grid-template-columns: 1fr; }
  .training-options { display: grid; }
  .training-options .primary-button { width: 100%; margin: 0; }
  .field-group select { width: 100%; }
  .flashcard { min-height: 390px; }
  .flashcard-inner { min-height: 390px; }
  .flashcard-controls { grid-template-columns: 1fr 1fr; }
  .flashcard-controls button { width: 100%; }
  .flashcard-controls button:first-child, .flashcard-controls button:last-child { justify-self: stretch; }
  .lesson-card-head { display: block; }
  .complete-button { width: 100%; margin-top: 15px; }
  .formula-count-banner { align-items: flex-start; }
  .formula-tabs { display: grid; width: 100%; }
  .formula-tab { width: 100%; }
  .quiz-card { padding: 22px 18px; }
  .dictation-controls { align-items: stretch; flex-direction: column; }
  .dictation-controls button { width: 100%; }
  .quiz-top { grid-template-columns: auto 1fr; }
  .quiz-top span { grid-column: 1 / -1; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}