:root {
  --bg: #f6f5f0;
  --surface: #ffffff;
  --surface2: #eeece6;
  --border: #d8d5cc;
  --border2: #c4c0b6;
  --accent: #2b5ea7;
  --accent2: #1a3d6d;
  --accent-light: rgba(43, 94, 167, 0.08);
  --good: #1b7d46;
  --good-bg: rgba(27, 125, 70, 0.08);
  --warn: #d4730e;
  --warn-bg: rgba(212, 115, 14, 0.08);
  --bad: #c0392b;
  --bad-bg: rgba(192, 57, 43, 0.08);
  --text: #1b1b1f;
  --text2: #4a4a52;
  --muted: #7a7a85;
  --dim: #a0a0aa;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, rgba(43, 94, 167, 0.12), transparent 32%),
    linear-gradient(180deg, #f6f5f0 0%, #f0ede4 100%);
  color: var(--text);
  font-family: "JetBrains Mono", monospace;
  line-height: 1.6;
}

a {
  color: inherit;
}

nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1.5rem;
  border-bottom: 1px solid var(--border);
  background: rgba(246, 245, 240, 0.94);
  backdrop-filter: blur(12px);
}

nav a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.72rem;
}

.wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(320px, 1fr);
  gap: 1rem;
  align-items: stretch;
}

.hero-card,
.panel,
.card-face,
.topic-grid,
.stats-grid,
.empty-state {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  box-shadow: 0 10px 30px rgba(20, 20, 30, 0.05);
}

.hero-card {
  padding: 1.4rem 1.5rem;
}

.hero-kicker {
  font-size: 0.64rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
}

h1,
h2,
h3 {
  font-family: "Fraunces", serif;
  margin: 0;
  letter-spacing: -0.02em;
}

h1 {
  margin-top: 0.6rem;
  font-size: clamp(2.3rem, 6vw, 4.4rem);
  line-height: 1;
}

.hero-copy {
  margin-top: 0.9rem;
  color: var(--text2);
  font-size: 0.82rem;
  max-width: 60ch;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.7rem;
  padding: 1rem;
}

.stat-card {
  background: var(--surface2);
  border-radius: 4px;
  padding: 0.8rem 0.9rem;
}

.stat-label {
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--dim);
}

.stat-value {
  display: block;
  margin-top: 0.35rem;
  font-family: "Fraunces", serif;
  font-size: 1.6rem;
}

.layout {
  display: grid;
  grid-template-columns: minmax(280px, 360px) minmax(0, 1fr);
  gap: 1rem;
  margin-top: 1rem;
}

.panel {
  padding: 1rem;
}

.panel h2 {
  font-size: 1.2rem;
}

.panel-copy {
  margin: 0.45rem 0 0.9rem;
  color: var(--muted);
  font-size: 0.73rem;
}

.topic-actions,
.mode-pills,
.card-actions,
.card-rating {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

button,
.mode-pill,
.topic-shortcut {
  border: 1px solid var(--border2);
  border-radius: 999px;
  background: transparent;
  color: var(--text2);
  font: inherit;
  font-size: 0.7rem;
  padding: 0.42rem 0.8rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

button:hover,
.mode-pill:hover,
.topic-shortcut:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-light);
}

button.active,
.mode-pill.active,
.topic-shortcut.active {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-light);
}

.topic-grid {
  padding: 0.4rem;
  max-height: 540px;
  overflow: auto;
}

.topic-option {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.7rem;
  align-items: start;
  padding: 0.75rem 0.8rem;
  border-radius: 4px;
}

.topic-option:hover {
  background: var(--surface2);
}

.topic-option input {
  margin-top: 0.25rem;
}

.topic-option-title {
  font-size: 0.76rem;
  color: var(--text);
}

.topic-option-copy {
  font-size: 0.67rem;
  color: var(--muted);
}

.topic-option-count {
  font-size: 0.67rem;
  color: var(--dim);
}

.card-stage {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  font-size: 0.58rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.stage-due,
.stage-review {
  background: var(--accent-light);
  color: var(--accent);
}

.stage-new {
  background: var(--surface2);
  color: var(--muted);
}

.stage-learning {
  background: var(--warn-bg);
  color: var(--warn);
}

.stage-mastered {
  background: var(--good-bg);
  color: var(--good);
}

.stage-weak {
  background: var(--bad-bg);
  color: var(--bad);
}

.session-panel {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.session-bar {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 1rem 1.1rem;
}

.session-progress {
  flex: 1 1 240px;
}

.progress-track {
  height: 8px;
  border-radius: 999px;
  background: var(--surface2);
  overflow: hidden;
  margin-top: 0.55rem;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), #4a83d0);
  transition: width 0.2s ease;
}

.card-face {
  padding: 1.2rem 1.25rem;
}

.card-head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: start;
  margin-bottom: 1rem;
}

.card-topic {
  font-size: 0.64rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--dim);
}

.card-tier {
  margin-top: 0.35rem;
  font-size: 0.8rem;
  color: var(--accent);
}

.card-question {
  min-height: 150px;
  font-size: clamp(1rem, 2.3vw, 1.4rem);
  line-height: 1.55;
  white-space: pre-wrap;
}

.card-answer {
  display: none;
  margin-top: 1rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface2);
  color: var(--text2);
  font-size: 0.82rem;
}

.card-answer.visible {
  display: block;
}

.card-actions {
  margin-top: 1rem;
}

.primary-btn {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

.primary-btn:hover {
  color: #fff;
  opacity: 0.92;
}

.rate-again {
  border-color: rgba(192, 57, 43, 0.3);
  background: var(--bad-bg);
  color: var(--bad);
}

.rate-hard {
  border-color: rgba(212, 115, 14, 0.3);
  background: var(--warn-bg);
  color: var(--warn);
}

.rate-good {
  border-color: rgba(27, 125, 70, 0.3);
  background: var(--good-bg);
  color: var(--good);
}

.empty-state {
  padding: 2rem;
  text-align: center;
}

.empty-state p {
  margin: 0.7rem auto 0;
  max-width: 48ch;
  font-size: 0.78rem;
  color: var(--muted);
}

.stats-page-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
  font-size: 0.74rem;
}

.stats-page-table th,
.stats-page-table td {
  padding: 0.75rem 0.7rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

.stats-page-table th {
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--dim);
}

@media (max-width: 980px) {
  .hero,
  .layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 700px) {
  nav {
    padding: 0.75rem 1rem;
  }

  .wrap {
    padding: 1.25rem 0.8rem 3rem;
  }

  .stats-grid {
    grid-template-columns: 1fr 1fr;
  }
}