/* ============================================================
   韩谷 (Hangugo) — 韩语教学静态站
   ============================================================ */

:root {
  --primary: #2d4b8f;
  --primary-light: #4a7bc4;
  --accent: #e67e22;
  --bg: #f5f7fa;
  --card-bg: #ffffff;
  --text: #2c3e50;
  --text-light: #7f8c8d;
  --border: #e0e4e8;
  --success: #27ae60;
  --radius: 12px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans KR', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

/* Header */
header {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: white;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

header h1 {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

header h1 span { color: #ffd700; }

header nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

header nav a {
  color: rgba(255,255,255,0.9);
  text-decoration: none;
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.2s;
}

header nav a:hover,
header nav a.active {
  background: rgba(255,255,255,0.2);
  color: white;
}

/* Level tabs */
.level-tabs {
  display: flex;
  gap: 4px;
  padding: 12px 24px;
  background: white;
  border-bottom: 1px solid var(--border);
  overflow-x: auto;
}

.level-tab {
  padding: 6px 16px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: transparent;
  color: var(--text-light);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.level-tab:hover { border-color: var(--primary-light); color: var(--primary); }

.level-tab.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* Main content */
main {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px 24px 80px;
}

.page-title {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--primary);
}

/* Stats bar */
.stats-bar {
  display: flex;
  gap: 16px;
  margin-bottom: 16px;
  font-size: 13px;
  color: var(--text-light);
}

.stats-bar span strong { color: var(--text); }

/* Vocab cards */
.vocab-list { display: flex; flex-direction: column; gap: 6px; }

.vocab-card {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all 0.15s;
}

.vocab-card:hover {
  border-color: var(--primary-light);
  box-shadow: 0 2px 8px rgba(45,75,143,0.08);
}

.vocab-card .target {
  font-size: 18px;
  font-weight: 600;
  min-width: 80px;
  color: var(--text);
}

.vocab-card .roman {
  font-size: 13px;
  color: var(--text-light);
  min-width: 90px;
  font-family: 'Segoe UI', sans-serif;
}

.vocab-card .meaning {
  flex: 1;
  font-size: 14px;
  color: var(--text);
}

.vocab-card .pos {
  font-size: 11px;
  color: var(--text-light);
  background: #eef2f7;
  padding: 2px 8px;
  border-radius: 10px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.vocab-card .play-btn {
  width: 36px;
  height: 36px;
  border: none;
  border-radius: 50%;
  background: var(--primary);
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  transition: all 0.2s;
  flex-shrink: 0;
}

.vocab-card .play-btn:hover { background: var(--primary-light); transform: scale(1.05); }
.vocab-card .play-btn:active { transform: scale(0.95); }
.vocab-card .play-btn.playing { background: var(--success); }

/* Small play button for grammar examples */
.play-btn-sm {
  width: 22px;
  height: 22px;
  border: none;
  border-radius: 50%;
  background: var(--primary-light);
  color: white;
  cursor: pointer;
  font-size: 10px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  vertical-align: middle;
  margin-left: 6px;
  transition: all 0.2s;
}
.play-btn-sm:hover { background: var(--primary); }
.play-btn-sm.playing { background: var(--success); }

/* Frequency stars */
.freq {
  color: #f1c40f;
  font-size: 11px;
  letter-spacing: 1px;
  flex-shrink: 0;
}

/* Grammar cards */
.grammar-list { display: flex; flex-direction: column; gap: 12px; }

.grammar-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
}

.grammar-card .point {
  font-size: 16px;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 6px;
}

.grammar-card .explanation {
  font-size: 14px;
  color: var(--text);
  margin-bottom: 10px;
  line-height: 1.7;
}

.grammar-card .examples {
  background: #f8f9fb;
  border-radius: 8px;
  padding: 10px 14px;
}

.grammar-card .examples .ex {
  font-size: 14px;
  padding: 4px 0;
}

.grammar-card .examples .ex .ko { font-weight: 500; }
.grammar-card .examples .ex .zh { color: var(--text-light); font-size: 13px; }

/* Search */
.search-box {
  margin-bottom: 16px;
  display: flex;
  gap: 8px;
}

.search-box input {
  flex: 1;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s;
}

.search-box input:focus { border-color: var(--primary-light); }

.search-box input::placeholder { color: #bbb; }

/* Loading / empty states */
.loading, .empty {
  text-align: center;
  padding: 48px 24px;
  color: var(--text-light);
}

.loading::before {
  content: '';
  display: block;
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 12px;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* Footer */
footer {
  text-align: center;
  padding: 24px;
  color: var(--text-light);
  font-size: 12px;
}

/* Responsive */
@media (max-width: 600px) {
  header { flex-direction: column; gap: 8px; padding: 12px 16px; }
  header h1 { font-size: 18px; }
  header nav a { font-size: 12px; padding: 4px 10px; }
  main { padding: 12px 12px 60px; }
  .vocab-card { padding: 10px 12px; gap: 8px; }
  .vocab-card .target { min-width: 60px; font-size: 16px; }
  .vocab-card .roman { min-width: 70px; font-size: 12px; }
}