:root {
  color-scheme: light;
  --bg: #ecfdf5;
  --surface: rgba(255, 255, 255, 0.9);
  --surface-warm: #f0fdfa;
  --text: #0f172a;
  --muted: #475569;
  --soft: #bae6fd;
  --accent: #0f766e;
  --accent-dark: #134e4a;
  --accent-soft: #ccfbf1;
  --blue: #0284c7;
  --blue-soft: #e0f2fe;
  --green: #10b981;
  --green-soft: #dcfce7;
  --yellow-soft: #fef9c3;
  --shadow: 0 16px 36px rgba(15, 118, 110, 0.08);
  --tab-height: 76px;
}

* {
  box-sizing: border-box;
}

html {
  background:
    linear-gradient(145deg, #ecfdf5 0%, #e0f2fe 52%, #f8fafc 100%);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

body {
  min-width: 320px;
  margin: 0;
  overflow-x: hidden;
}

button,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

a {
  color: inherit;
}

.app-shell {
  width: min(100%, 940px);
  margin: 0 auto;
  padding: 18px 16px calc(var(--tab-height) + 32px);
}

.topbar {
  display: grid;
  gap: 14px;
  padding: 6px 0 16px;
}

.back-link {
  display: inline-flex;
  width: fit-content;
  min-height: 44px;
  align-items: center;
  color: var(--accent-dark);
  font-weight: 760;
  text-decoration: none;
}

.kicker {
  margin: 0 0 8px;
  color: var(--accent-dark);
  font-size: 0.92rem;
  font-weight: 760;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  margin: 0;
  font-size: clamp(2.05rem, 9vw, 4rem);
  line-height: 1.02;
  letter-spacing: 0;
}

.subtitle {
  max-width: 42rem;
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 1.04rem;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 8px 0 16px;
}

.stat-button {
  min-height: 68px;
  border: 1px solid var(--soft);
  border-radius: 20px;
  background: var(--surface);
  color: var(--text);
  padding: 12px;
  text-align: left;
  box-shadow: 0 10px 24px rgba(14, 116, 144, 0.06);
}

.stat-button.is-active {
  border-color: rgba(15, 118, 110, 0.45);
  background: linear-gradient(135deg, #ccfbf1 0%, #e0f2fe 100%);
}

.stat-number {
  display: block;
  font-size: 1.35rem;
  font-weight: 820;
  line-height: 1;
}

.stat-label {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 720;
}

.notice {
  margin: 0 0 14px;
  border-radius: 16px;
  background: var(--yellow-soft);
  color: #3f3a13;
  padding: 12px 14px;
  font-weight: 720;
}

.notice[hidden] {
  display: none;
}

.voice-settings {
  display: grid;
  gap: 12px;
  margin: 0 0 16px;
  border: 1px solid var(--soft);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: 0 10px 24px rgba(14, 116, 144, 0.06);
  padding: 16px;
}

.voice-settings[hidden] {
  display: none;
}

.voice-settings h2 {
  margin: 0;
  font-size: 1.12rem;
  letter-spacing: 0;
}

.voice-grid {
  display: grid;
  gap: 10px;
}

.voice-note {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.view {
  display: grid;
  gap: 14px;
}

.panel,
.phrase-card,
.quiz-card,
.review-card {
  border: 1px solid var(--soft);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.panel {
  padding: 18px;
}

.panel h2,
.panel h3,
.quiz-card h3 {
  margin: 0;
  letter-spacing: 0;
}

.panel h2,
.quiz-card h3 {
  font-size: 1.45rem;
}

.panel h3 {
  font-size: 1.08rem;
}

.muted {
  color: var(--muted);
}

.section-note {
  margin: 8px 0 0;
  color: var(--muted);
}

.today-meta {
  display: grid;
  gap: 10px;
  margin-top: 14px;
}

.meta-pill {
  border-radius: 18px;
  background: var(--surface-warm);
  padding: 12px;
}

.meta-label {
  display: block;
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 760;
}

.meta-text {
  display: block;
  margin-top: 3px;
  font-weight: 740;
}

.card-stack {
  display: grid;
  gap: 12px;
}

.phrase-card {
  display: grid;
  gap: 14px;
  padding: 16px;
}

.phrase-main {
  display: grid;
  gap: 8px;
}

.spanish {
  margin: 0;
  font-size: clamp(1.35rem, 6vw, 2rem);
  line-height: 1.18;
  font-weight: 820;
}

.chinese {
  margin: 0;
  color: var(--text);
  font-size: 1.05rem;
  font-weight: 740;
}

.usage {
  margin: 0;
  color: var(--muted);
}

.tag-row,
.action-row,
.status-row,
.filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  display: inline-flex;
  min-height: 32px;
  align-items: center;
  border-radius: 999px;
  background: var(--surface-warm);
  color: var(--accent-dark);
  padding: 6px 10px;
  font-size: 0.82rem;
  font-weight: 760;
}

.soft-button,
.voice-button,
.status-button,
.finish-button,
.next-button,
.favorite-button {
  min-height: 44px;
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 10px 13px;
  font-weight: 780;
}

.voice-button,
.soft-button,
.favorite-button {
  background: var(--surface-warm);
  color: var(--accent-dark);
}

.favorite-button.is-active {
  background: var(--yellow-soft);
  color: #3f3a13;
}

.status-button {
  background: #f1f5f9;
  color: var(--muted);
}

.status-button.is-active {
  background: var(--green-soft);
  color: var(--green);
  border-color: rgba(16, 185, 129, 0.35);
}

.finish-button,
.next-button {
  width: 100%;
  background: var(--accent);
  color: #ffffff;
}

.finish-button:hover,
.next-button:hover {
  background: #0e7490;
}

.finish-button.is-done {
  background: var(--green);
}

.quiz-card {
  padding: 16px;
}

.vocab-list {
  display: grid;
  gap: 10px;
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
}

.vocab-list li {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  border-radius: 16px;
  background: var(--surface-warm);
  padding: 11px 12px;
}

.plan-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.day-tile {
  min-height: 92px;
  border: 1px solid var(--soft);
  border-radius: 18px;
  background: var(--surface);
  padding: 10px;
  text-align: left;
}

.day-tile.is-done {
  background: var(--green-soft);
  border-color: rgba(16, 185, 129, 0.35);
}

.day-tile.is-active {
  border-color: rgba(14, 116, 144, 0.62);
  background: linear-gradient(135deg, #ccfbf1 0%, #e0f2fe 100%);
  box-shadow: 0 12px 28px rgba(14, 116, 144, 0.12);
}

.day-number {
  display: block;
  color: var(--accent-dark);
  font-size: 0.82rem;
  font-weight: 820;
}

.day-title {
  display: block;
  margin-top: 6px;
  font-size: 0.9rem;
  font-weight: 760;
}

.day-state {
  display: inline-flex;
  min-height: 28px;
  align-items: center;
  margin-top: 9px;
  border-radius: 999px;
  background: rgba(248, 250, 252, 0.72);
  color: var(--muted);
  padding: 4px 8px;
  font-size: 0.76rem;
  font-weight: 780;
}

.day-actions {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.library-tools {
  display: grid;
  gap: 10px;
}

.select-field {
  display: grid;
  gap: 6px;
}

.select-field label {
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 760;
}

select {
  width: 100%;
  min-height: 48px;
  border: 1px solid var(--soft);
  border-radius: 16px;
  background: var(--surface);
  color: var(--text);
  padding: 10px 12px;
}

.review-card {
  display: grid;
  gap: 14px;
  padding: 18px;
}

.bottom-tabs {
  position: fixed;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 10;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 6px;
  min-height: var(--tab-height);
  border-top: 1px solid rgba(19, 78, 74, 0.5);
  background: rgba(15, 23, 42, 0.94);
  padding: 8px 10px calc(8px + env(safe-area-inset-bottom));
  backdrop-filter: blur(18px);
}

.tab-button {
  min-height: 52px;
  border: 0;
  border-radius: 18px;
  background: transparent;
  color: #bae6fd;
  font-size: 0.92rem;
  font-weight: 820;
}

.tab-button.is-active {
  background: linear-gradient(135deg, #0f766e 0%, #0284c7 100%);
  color: #ffffff;
}

button:focus-visible,
a:focus-visible,
select:focus-visible {
  outline: 3px solid rgba(14, 116, 144, 0.28);
  outline-offset: 3px;
}

@media (min-width: 680px) {
  .app-shell {
    padding: 34px 24px calc(var(--tab-height) + 42px);
  }

  .stats-grid {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }

  .today-meta,
  .library-tools,
  .voice-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .card-stack {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .day-actions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .phrase-card:first-child:nth-last-child(1) {
    grid-column: auto;
  }

  .plan-grid {
    grid-template-columns: repeat(7, minmax(0, 1fr));
  }
}