:root {
  --bg: #eef1f5;
  --surface: #ffffff;
  --surface-2: #f6f7f9;
  --ink: #1d2635;
  --muted: #687386;
  --brand: #24324a;
  --brand-2: #364b70;
  --accent: #d99b33;
  --success: #2e7d5b;
  --danger: #a63d43;
  --border: #d8dde6;
  --shadow: 0 14px 35px rgba(32, 45, 67, 0.12);
  --radius: 18px;
}

* { box-sizing: border-box; }
html { background: var(--bg); }
body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 20% 0%, rgba(217,155,51,.12), transparent 24rem),
    var(--bg);
}
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { opacity: .5; cursor: not-allowed; }

.app-shell { max-width: 920px; margin: 0 auto; min-height: 100vh; padding-bottom: 92px; }
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 22px 20px 12px;
}
.eyebrow { color: var(--muted); font-size: .75rem; font-weight: 800; letter-spacing: .09em; text-transform: uppercase; }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 0; font-size: 1.8rem; letter-spacing: -.03em; }
h2 { margin-bottom: 0; letter-spacing: -.025em; }
h3 { margin-bottom: 12px; }
main { padding: 8px 16px 24px; }
.view { display: none; }
.view.active { display: block; animation: fade .18s ease; }
@keyframes fade { from { opacity: .35; transform: translateY(3px); } }

.card-panel, .trainer-card, .stat-card, .item-card {
  background: var(--surface); border: 1px solid rgba(216,221,230,.85); box-shadow: var(--shadow);
}
.card-panel { border-radius: var(--radius); padding: 16px; }
.practice-toolbar { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)) auto; gap: 12px; align-items: end; }
.field { display: grid; gap: 7px; }
.field span, .field label, .field > label { font-weight: 750; font-size: .88rem; }
.field.compact label { font-size: .76rem; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; }
input, select, textarea {
  width: 100%; border: 1px solid var(--border); border-radius: 12px; padding: 12px 13px;
  background: #fff; color: var(--ink); outline: none;
}
input:focus, select:focus, textarea:focus { border-color: var(--brand-2); box-shadow: 0 0 0 3px rgba(54,75,112,.12); }

.primary-btn, .secondary-btn, .ghost-btn, .danger-btn, .success-btn, .danger-outline-btn, .link-btn, .icon-btn {
  border: 0; border-radius: 12px; min-height: 44px; padding: 11px 15px; font-weight: 800;
}
.primary-btn { background: var(--brand); color: white; }
.secondary-btn { background: #e8ecf3; color: var(--brand); }
.ghost-btn { background: transparent; color: var(--brand); border: 1px solid var(--border); }
.danger-btn { background: var(--danger); color: white; }
.success-btn { background: var(--success); color: white; }
.danger-outline-btn { color: var(--danger); background: transparent; border: 1px solid rgba(166,61,67,.4); }
.link-btn { min-height: auto; padding: 4px; background: transparent; color: var(--brand-2); }
.icon-btn { min-width: 44px; padding: 8px; background: var(--surface-2); }
.full-width { width: 100%; }

.session-strip { display: flex; justify-content: center; gap: 18px; flex-wrap: wrap; color: var(--muted); font-size: .9rem; padding: 14px 8px 10px; }
.session-strip strong { color: var(--ink); }
.trainer-card {
  max-width: 650px; margin: 0 auto; border-radius: 26px; padding: 22px;
  min-height: 430px; display: flex; flex-direction: column;
}
.card-meta { display: flex; justify-content: space-between; gap: 8px; }
.badge { display: inline-flex; align-items: center; padding: 7px 10px; border-radius: 99px; background: #e7edf7; color: var(--brand); font-size: .78rem; font-weight: 850; }
.badge.muted { background: var(--surface-2); color: var(--muted); }
.task-block { display: flex; flex: 1; flex-direction: column; align-items: center; justify-content: center; text-align: center; padding: 30px 0 20px; }
.translation { color: var(--muted); margin-bottom: 7px; font-size: 1.02rem; }
.task-block h2 { font-size: clamp(2.5rem, 11vw, 4.5rem); line-height: 1; margin-bottom: 18px; }
.person-prompt { display: flex; align-items: center; gap: 10px; font-size: 1.25rem; font-weight: 850; margin-bottom: 26px; }
.person-prompt .arrow { color: var(--accent); }
.answer-area { width: min(100%, 430px); display: grid; grid-template-columns: 1fr auto; gap: 10px; }
.answer-area input { text-align: center; font-size: 1.15rem; }
.answer-area:has(#revealBtn) { display: block; }
.instruction { color: var(--muted); max-width: 430px; }
.choice-grid { width: min(100%, 520px); display: grid; grid-template-columns: repeat(3,1fr); gap: 9px; margin: 8px 0 18px; }
.choice-btn { border: 1px solid var(--border); border-radius: 12px; background: #fff; padding: 11px 8px; color: var(--ink); font-weight: 800; }
.choice-btn.selected { background: var(--brand); color: white; border-color: var(--brand); }
.choice-btn.correct { background: rgba(46,125,91,.14); color: var(--success); border-color: rgba(46,125,91,.45); }
.choice-btn.wrong { background: rgba(166,61,67,.12); color: var(--danger); border-color: rgba(166,61,67,.4); }
.feedback { border-top: 1px solid var(--border); padding-top: 16px; display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.feedback-label { display: block; font-size: .8rem; font-weight: 900; text-transform: uppercase; letter-spacing: .07em; color: var(--muted); }
.correct-answer { display: block; font-size: 1.35rem; margin-top: 2px; }
.feedback-note { color: var(--muted); margin: 5px 0 0; font-size: .9rem; }
.feedback.good .feedback-label { color: var(--success); }
.feedback.bad .feedback-label { color: var(--danger); }
.grade-buttons { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 14px; }

.section-heading { display: flex; justify-content: space-between; align-items: end; margin: 4px 0 16px; }
.section-note { color: var(--muted); }
.search-row { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 10px; margin-bottom: 13px; }
.count-pill { padding: 8px 10px; border-radius: 99px; background: #dde3ed; font-weight: 800; color: var(--brand); }
.item-list { display: grid; gap: 10px; }
.item-card { border-radius: 16px; padding: 15px; display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.item-card button { text-align: left; background: transparent; border: 0; padding: 0; flex: 1; color: inherit; }
.item-card strong { display: block; font-size: 1.1rem; }
.item-card small { color: var(--muted); }
.chevron { color: var(--muted); font-size: 1.3rem; }

.stats-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 10px; margin-bottom: 14px; }
.stat-card { border-radius: 16px; padding: 16px; }
.stat-card span { display: block; color: var(--muted); font-size: .82rem; }
.stat-card strong { font-size: 1.8rem; }
.settings-panel, .data-panel { margin-top: 14px; }
.switch-row { display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 14px 0; border-top: 1px solid var(--border); }
.switch-row:first-of-type { border-top: 0; }
.switch-row strong, .switch-row small { display: block; }
.switch-row small { color: var(--muted); margin-top: 4px; }
.switch-row input { width: 22px; height: 22px; flex: none; }
.button-stack { display: grid; gap: 10px; }
.file-label { display: flex; align-items: center; justify-content: center; cursor: pointer; }
.file-label input { display: none; }

.bottom-nav {
  position: fixed; z-index: 20; left: 50%; bottom: 0; transform: translateX(-50%);
  width: min(920px,100%); display: grid; grid-template-columns: repeat(4,1fr); gap: 2px;
  background: rgba(255,255,255,.94); backdrop-filter: blur(14px); border-top: 1px solid var(--border);
  padding: 8px 8px calc(8px + env(safe-area-inset-bottom));
}
.nav-btn { border: 0; border-radius: 12px; background: transparent; color: var(--muted); padding: 7px 3px; font-size: .72rem; font-weight: 800; }
.nav-btn span { display: block; font-size: 1.2rem; margin-bottom: 2px; }
.nav-btn.active { background: #e7ebf2; color: var(--brand); }

.app-dialog { border: 0; padding: 0; background: transparent; width: min(680px, calc(100% - 20px)); max-height: calc(100vh - 28px); }
.app-dialog::backdrop { background: rgba(17,25,39,.54); backdrop-filter: blur(3px); }
.wide-dialog { width: min(840px, calc(100% - 20px)); }
.dialog-card { background: var(--surface); border-radius: 22px; padding: 20px; max-height: calc(100vh - 28px); overflow: auto; box-shadow: 0 30px 80px rgba(0,0,0,.26); }
.dialog-heading { display: flex; justify-content: space-between; align-items: start; gap: 15px; margin-bottom: 16px; }
.dialog-actions { display: flex; justify-content: space-between; gap: 10px; margin-top: 18px; }
.dialog-actions .primary-btn { margin-left: auto; }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.hint { color: var(--muted); font-size: .86rem; margin: 8px 0 0; }
.forms-editor { display: grid; gap: 14px; margin-top: 18px; }
.tense-editor { border: 1px solid var(--border); border-radius: 16px; padding: 14px; }
.tense-editor h3 { margin-bottom: 10px; }
.person-form-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 9px; }
.person-form-grid label { display: grid; gap: 4px; color: var(--muted); font-size: .78rem; font-weight: 750; }
.person-form-grid input { padding: 10px; }
.filter-actions { display: flex; gap: 15px; margin-bottom: 14px; }
.check-list { display: grid; gap: 8px; margin-bottom: 18px; }
.check-list.two-col { grid-template-columns: 1fr 1fr; }
.check-row { display: flex; align-items: center; gap: 9px; padding: 9px 10px; background: var(--surface-2); border-radius: 11px; }
.check-row input { width: 19px; height: 19px; flex: none; }
.verb-check-list { max-height: 260px; overflow: auto; padding-right: 3px; }
.empty-state { text-align: center; color: var(--muted); padding: 30px 15px; }
.toast { position: fixed; z-index: 100; left: 50%; bottom: 94px; transform: translateX(-50%); max-width: calc(100% - 28px); padding: 12px 16px; border-radius: 12px; background: var(--ink); color: #fff; box-shadow: var(--shadow); }
.hidden { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; }

@media (max-width: 700px) {
  .practice-toolbar { grid-template-columns: 1fr 1fr; }
  .practice-toolbar > button { grid-column: 1 / -1; }
  .trainer-card { min-height: 450px; padding: 18px; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .person-form-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 430px) {
  .topbar { padding-left: 16px; padding-right: 16px; }
  main { padding-left: 10px; padding-right: 10px; }
  .practice-toolbar { grid-template-columns: 1fr; }
  .practice-toolbar > button { grid-column: auto; }
  .answer-area { grid-template-columns: 1fr; }
  .choice-grid { grid-template-columns: repeat(2,1fr); }
  .form-grid, .check-list.two-col { grid-template-columns: 1fr; }
  .person-form-grid { grid-template-columns: 1fr; }
  .dialog-card { padding: 16px; }
  .nav-btn { font-size: .64rem; }
}