:root {
  color-scheme: dark;
  --bg: #0b1220;
  --panel: #121d2e;
  --panel-2: #17243a;
  --text: #f5f7fb;
  --muted: #aeb9ca;
  --line: rgba(255,255,255,.10);
  --accent: #7cc4ff;
  --accent-2: #9ee6c1;
  --warn: #ffd38a;
  --danger: #ff9c9c;
  --nav-bg: rgba(11,18,32,.96);
  --soft-fill: rgba(255,255,255,.04);
  --feedback-bg: rgba(255,255,255,.05);
  --progress-track: rgba(255,255,255,.07);
  --accent-outline: rgba(124,196,255,.5);
  --medical-text: #f4dfb7;
  --primary-bg: #eaf5ff;
  --primary-text: #07111f;
  --backdrop: rgba(0,0,0,.66);
  --nav-h: 72px;
  --radius: 18px;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; touch-action: pan-x pan-y; overscroll-behavior-x: none; }
html, body { margin: 0; min-height: 100%; background: var(--bg); color: var(--text); }
body { min-height: 100dvh; overflow-x: hidden; overscroll-behavior-x: none; }
button, select, input { -webkit-tap-highlight-color: transparent; touch-action: manipulation; }
.topbar, .bottom-nav, button, .eyebrow, .badge, .field-label, .lesson-counter, .dialog-header {
  -webkit-user-select: none; user-select: none; -webkit-touch-callout: none;
}
button, input, select { font: inherit; }
button { color: inherit; }
.app-shell { min-height: 100dvh; padding-bottom: calc(var(--nav-h) + env(safe-area-inset-bottom)); }
.topbar {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: calc(env(safe-area-inset-top) + 35px) 18px 14px;
  background: var(--bg);
}
.topbar h1 { margin: 2px 0 0; font-size: 1.42rem; letter-spacing: -.02em; }
.eyebrow { color: var(--accent); font-size: .68rem; font-weight: 800; letter-spacing: .12em; }
.main { padding: 8px 16px 28px; max-width: 820px; margin: 0 auto; }
.bottom-nav {
  position: fixed; z-index: 20; left: 0; right: 0; bottom: 0;
  min-height: calc(var(--nav-h) + env(safe-area-inset-bottom));
  padding: 8px 8px env(safe-area-inset-bottom);
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px;
  border-top: 1px solid var(--line); background: var(--nav-bg); backdrop-filter: blur(18px); -webkit-backdrop-filter: blur(18px);
}
.nav-item { border: 0; background: transparent; color: var(--muted); border-radius: 14px; min-height: 54px; font-weight: 750; }
.nav-item.active { background: var(--panel-2); color: var(--text); }
.icon-button { width: 42px; height: 42px; border-radius: 50%; border: 1px solid var(--line); background: var(--panel); font-size: 1.3rem; }
.hero, .card, .lesson-card, .item-card, .practice-card, .notice { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); }
.hero { padding: 18px; margin-bottom: 14px; }
.hero h2 { margin: 0 0 8px; font-size: 1.45rem; }
.hero p { margin: 0; color: var(--muted); line-height: 1.5; }
.stat-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-top: 16px; }
.stat { background: var(--soft-fill); border-radius: 14px; padding: 12px; }
.stat strong { display: block; font-size: 1.15rem; }
.stat span { display: block; color: var(--muted); font-size: .76rem; margin-top: 3px; }
.section-title { margin: 22px 2px 10px; font-size: 1rem; }
.lesson-list { display: grid; gap: 10px; }
.lesson-card { padding: 15px; display: grid; grid-template-columns: 1fr auto; gap: 12px; align-items: center; }
.lesson-card h3 { margin: 0 0 4px; font-size: 1rem; }
.lesson-card p { margin: 0; color: var(--muted); line-height: 1.35; font-size: .88rem; }
.lesson-meta { display: flex; gap: 7px; flex-wrap: wrap; margin-top: 10px; }
.badge { display: inline-flex; align-items: center; min-height: 24px; padding: 3px 8px; border-radius: 999px; background: var(--soft-fill); color: var(--muted); font-size: .7rem; font-weight: 760; }
.badge.active { color: var(--accent-2); }
.badge.medical { color: var(--warn); }
.primary-button, .secondary-button, .chip-button, .danger-button {
  border-radius: 12px; border: 1px solid var(--line); min-height: 42px; padding: 9px 13px; font-weight: 760;
}
.primary-button { background: var(--primary-bg); color: var(--primary-text); border-color: transparent; }
.secondary-button, .chip-button { background: var(--panel-2); }
.danger-button { background: transparent; color: var(--danger); }
.search-row { display: grid; grid-template-columns: 1fr auto; gap: 8px; margin-bottom: 10px; }
.search-input, select { width: 100%; min-height: 44px; border-radius: 12px; border: 1px solid var(--line); background: var(--panel); color: var(--text); padding: 10px 12px; }
.filter-row { display: flex; gap: 8px; overflow-x: auto; padding-bottom: 8px; }
.chip-button { white-space: nowrap; min-height: 36px; padding: 7px 10px; color: var(--muted); }
.chip-button.active { color: var(--text); outline: 1px solid var(--accent-outline); }
.item-list { display: grid; gap: 10px; margin-top: 10px; }
.item-card { padding: 15px; }
.item-top { display: flex; justify-content: space-between; gap: 12px; align-items: start; }
.item-card h3 { font-size: 1.2rem; margin: 0; }
.item-card .meaning { margin: 6px 0 0; color: var(--text); font-weight: 650; }
.item-card .natural { color: var(--muted); margin: 4px 0 0; }
.item-actions { display: flex; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
.detail-grid { display: grid; gap: 10px; margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--line); }
.detail-row { display: grid; grid-template-columns: 110px 1fr; gap: 10px; font-size: .88rem; line-height: 1.45; }
.detail-row dt { color: var(--muted); }
.detail-row dd { margin: 0; }
.notice { padding: 13px 14px; margin: 10px 0; color: var(--muted); line-height: 1.45; }
.notice.medical { border-color: color-mix(in srgb, var(--warn) 35%, transparent); color: var(--medical-text); }
.progress-line { height: 7px; background: var(--progress-track); border-radius: 999px; overflow: hidden; }
.progress-line > div { height: 100%; background: currentColor; color: var(--accent); }
.lesson-view-header { margin-bottom: 14px; }
.lesson-view-header h2 { margin: 4px 0 6px; }
.lesson-counter { color: var(--muted); font-size: .85rem; }
.learn-card { padding: 18px; }
.learn-card .spanish { font-size: 1.65rem; margin: 0 0 8px; }
.learn-card .english { font-size: 1.02rem; margin: 0; }
.learn-card .natural { color: var(--muted); margin-top: 4px; }
.lesson-controls { display: grid; grid-template-columns: auto 1fr auto; gap: 8px; align-items: center; margin-top: 12px; }
.practice-card { padding: 17px; }
.practice-card h2 { margin-top: 0; }
.option-grid { display: grid; gap: 8px; margin-top: 14px; }
.option-button { text-align: left; min-height: 48px; border-radius: 12px; border: 1px solid var(--line); background: var(--panel-2); padding: 11px 12px; }
.option-button.correct { outline: 2px solid var(--accent-2); }
.option-button.wrong { outline: 2px solid var(--danger); }
.feedback { margin-top: 13px; padding: 12px; border-radius: 12px; background: var(--feedback-bg); line-height: 1.45; }
.token-bank, .token-answer { display: flex; gap: 8px; flex-wrap: wrap; min-height: 48px; padding: 9px; border: 1px dashed var(--line); border-radius: 12px; margin-top: 10px; }
.token { border: 1px solid var(--line); border-radius: 10px; background: var(--panel-2); padding: 8px 10px; }
.empty { text-align: center; color: var(--muted); padding: 36px 12px; }
.small { font-size: .82rem; }
.muted { color: var(--muted); }
.settings-dialog { border: 0; background: transparent; padding: 0; width: min(92vw, 520px); }
.settings-dialog::backdrop { background: var(--backdrop); }
.dialog-card { background: var(--panel); color: var(--text); border: 1px solid var(--line); border-radius: 20px; padding: 18px; }
.dialog-header { display: flex; justify-content: space-between; align-items: center; }
.dialog-header h2 { margin: 3px 0 12px; }
.field-label { display: block; font-size: .8rem; color: var(--muted); margin: 14px 0 6px; }
hr { border: 0; border-top: 1px solid var(--line); margin: 18px 0; }
.brand-note { line-height: 1.45; }
::selection { background: var(--accent-outline); }
@media (min-width: 760px) {
  .main { padding-left: 22px; padding-right: 22px; }
  .bottom-nav { left: 50%; transform: translateX(-50%); width: min(720px, 100%); border-left: 1px solid var(--line); border-right: 1px solid var(--line); border-radius: 18px 18px 0 0; }
  .lesson-list { grid-template-columns: repeat(2, minmax(0,1fr)); }
}