:root {
  --bg: #f6efe2;
  --paper: rgba(255, 250, 243, 0.88);
  --ink: #1f2430;
  --muted: #59606d;
  --line: rgba(60, 44, 27, 0.12);
  --accent: #ca5f32;
  --accent-deep: #8e3a1c;
  --accent-soft: #efd3bb;
  --success: #2c7a58;
  --danger: #b24b52;
  --shadow: 0 16px 40px rgba(78, 55, 33, 0.12);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 12px;
  font-family: "Segoe UI", "PingFang SC", "Hiragino Sans GB", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(202, 95, 50, 0.2), transparent 28%),
    radial-gradient(circle at bottom right, rgba(44, 122, 88, 0.18), transparent 24%),
    linear-gradient(180deg, #f8f1e7 0%, #efe3d1 100%);
}

button {
  font: inherit;
}

.app-shell {
  width: min(960px, 100%);
  margin: 0 auto;
  padding: 24px 16px 48px;
}

.hero,
.panel {
  background: var(--paper);
  backdrop-filter: blur(18px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.hero {
  display: grid;
  gap: 18px;
  padding: 24px;
}

.eyebrow {
  margin: 0 0 8px;
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent-deep);
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  font-size: clamp(2rem, 8vw, 3.8rem);
  line-height: 0.95;
  margin-bottom: 14px;
}

.hero-text,
.section-title p,
.metric p,
.grammar-meta,
.flashcard-hint,
.roadmap-card p {
  color: var(--muted);
}

.hero-stats,
.roadmap,
.progress-cards,
.grammar-list {
  display: grid;
  gap: 14px;
}

.stat-card,
.roadmap-card,
.metric,
.grammar-card,
.kana-tile {
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
}

.stat-card {
  padding: 16px;
  background: rgba(255, 255, 255, 0.55);
}

.stat-card strong {
  display: block;
  font-size: 1.7rem;
}

.roadmap-panel,
.tab-panel {
  margin-top: 18px;
}

.panel {
  padding: 18px;
}

.section-title {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: end;
  margin-bottom: 18px;
}

.roadmap-card {
  padding: 16px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.72), rgba(255, 246, 238, 0.88));
}

.roadmap-card span,
.metric span {
  display: inline-flex;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-deep);
  font-size: 0.85rem;
}

.tabbar {
  position: sticky;
  bottom: 14px;
  z-index: 20;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  padding: 10px;
  margin-top: 18px;
  background: rgba(255, 248, 240, 0.88);
  backdrop-filter: blur(18px);
  border-radius: 999px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.tab,
.chip,
.ghost,
.success,
.danger {
  border: 0;
  cursor: pointer;
}

.tab,
.chip,
.ghost {
  background: transparent;
}

.tab {
  padding: 12px 10px;
  border-radius: 999px;
  color: var(--muted);
}

.tab.active,
.chip.active {
  background: var(--ink);
  color: #fff;
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

.kana-toolbar,
.filter-row,
.review-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.chip,
.ghost,
.success,
.danger {
  border-radius: 999px;
  padding: 12px 16px;
}

.chip {
  border: 1px solid var(--line);
}

.kana-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(74px, 1fr));
  gap: 10px;
  margin-top: 16px;
}

.kana-tile {
  padding: 16px 10px;
  text-align: center;
  background: rgba(255, 255, 255, 0.55);
}

.kana-tile strong {
  display: block;
  font-size: 1.6rem;
  margin-bottom: 6px;
}

.flashcard {
  min-height: 260px;
  margin: 18px 0;
  padding: 24px;
  display: grid;
  align-content: space-between;
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(202, 95, 50, 0.15), rgba(255, 255, 255, 0.75)),
    rgba(255, 255, 255, 0.7);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.flashcard-stage {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: center;
}

.flashcard-stage span {
  padding: 7px 11px;
  border-radius: 999px;
  background: rgba(31, 36, 48, 0.08);
}

.flashcard-face {
  font-size: clamp(2rem, 8vw, 3.2rem);
  line-height: 1.1;
  margin: 24px 0 12px;
}

.flashcard-back {
  font-size: 1.1rem;
}

.ghost {
  background: rgba(31, 36, 48, 0.08);
}

.success {
  background: var(--success);
  color: #fff;
}

.danger {
  background: var(--danger);
  color: #fff;
}

.grammar-card {
  padding: 18px;
  background: rgba(255, 255, 255, 0.58);
}

.grammar-card h3 {
  margin-bottom: 8px;
}

.grammar-meta {
  font-size: 0.95rem;
  margin-bottom: 12px;
}

.progress-cards {
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}

.metric {
  padding: 16px;
  background: rgba(255, 255, 255, 0.58);
}

@media (min-width: 720px) {
  .hero {
    grid-template-columns: 1.6fr 1fr;
    align-items: center;
  }

  .hero-stats,
  .roadmap {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 719px) {
  .section-title {
    flex-direction: column;
    align-items: start;
  }

  .tabbar {
    grid-template-columns: repeat(2, 1fr);
  }
}