:root{
  --bg: #0b1020;
  --bg2: #0f1730;
  --text: #e9eefc;
  --muted: #a9b3d1;
  --card: rgba(255,255,255,0.06);
  --card2: rgba(255,255,255,0.08);
  --border: rgba(255,255,255,0.12);
  --shadow: 0 10px 30px rgba(0,0,0,0.25);
  --accent: #7aa2ff;
  --danger: #ff6b6b;
  --ok: #4ee59a;

  --radius: 16px;
  --radius-sm: 12px;
  --pad: 18px;
  --max: 1000px;
}

html[data-theme="light"]{
  --bg: #f6f8ff;
  --bg2: #ffffff;
  --text: #121a2b;
  --muted: #58627a;
  --card: rgba(10,20,40,0.04);
  --card2: rgba(10,20,40,0.06);
  --border: rgba(10,20,40,0.10);
  --shadow: 0 10px 30px rgba(10,20,40,0.10);
  --accent: #2d62ff;
  --danger: #d93535;
  --ok: #0fa96a;
}

*{ box-sizing: border-box; }
body{
  margin:0;
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 10% 10%, rgba(122,162,255,0.22), transparent 60%),
    radial-gradient(900px 500px at 90% 20%, rgba(88,227,197,0.18), transparent 60%),
    linear-gradient(180deg, var(--bg), var(--bg2));
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  line-height: 1.55;
}

a{ color: var(--accent); text-decoration: none; }
a:hover{ text-decoration: underline; }

.container{
  max-width: var(--max);
  margin: 0 auto;
  padding: 22px;
}

.site-header{
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(10px);
  background: rgba(0,0,0,0.20);
  border-bottom: 1px solid var(--border);
}
html[data-theme="light"] .site-header{
  background: rgba(246,248,255,0.70);
}

.header-inner{
  display:flex;
  align-items:center;
  justify-content: space-between;
  gap: 12px;
}

.brand{
  font-weight: 800;
  letter-spacing: 0.2px;
  color: var(--text);
  text-decoration:none;
}

.nav{
  display:flex;
  align-items:center;
  gap: 12px;
  flex-wrap: wrap;
}
.nav a{
  color: var(--text);
  opacity: 0.9;
}
.nav a:hover{ opacity: 1; text-decoration:none; }

.site-footer{
  border-top: 1px solid var(--border);
  margin-top: 26px;
}
.footer-inner{
  display:flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

h1{ font-size: clamp(1.8rem, 3.5vw, 2.4rem); margin: 10px 0 6px; }
h2{ font-size: 1.2rem; margin: 0 0 12px; }
.small{ font-size: 0.92rem; }
.muted{ color: var(--muted); }
.mt{ margin-top: 12px; }

.page-head{
  display:flex;
  gap: 14px;
  align-items:flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.card{
  background: var(--card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  border-radius: var(--radius);
  padding: var(--pad);
  margin: 14px 0;
}

.grid{
  display:grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  margin: 18px 0 8px;
}

.story-list{
  list-style: none;
  margin: 0;
  padding: 0;
}
.story-list li{
  margin: 8px 0;
}
.story-list a{
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.04);
  text-decoration: none;
  color: var(--text);
}
.story-list a:hover{
  background: rgba(255,255,255,0.08);
}

.week-card{
  display:block;
  padding: 16px;
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--card2), var(--card));
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: transform 120ms ease, border-color 120ms ease;
  color: var(--text);
  text-decoration:none;
}
.week-card:hover{
  transform: translateY(-2px);
  border-color: rgba(122,162,255,0.4);
  text-decoration:none;
}
.week-badge{
  display:inline-block;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(122,162,255,0.15);
  border: 1px solid rgba(122,162,255,0.25);
  font-weight: 700;
  font-size: 0.9rem;
}
.week-title{
  margin-top: 10px;
  font-weight: 800;
  font-size: 1.05rem;
}
.week-sub{
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.95rem;
}

/* Make the special card stand out a bit */
.special-card{
  border-color: rgba(88,227,197,0.40);
}
.special-card .week-badge{
  background: rgba(88,227,197,0.14);
  border-color: rgba(88,227,197,0.28);
}

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap: 8px;
  padding: 10px 14px;
  border-radius: 999px;
  border: 1px solid rgba(122,162,255,0.35);
  background: rgba(122,162,255,0.16);
  color: var(--text);
  cursor:pointer;
  font-weight: 700;
  text-decoration:none;
}
.btn:hover{
  border-color: rgba(122,162,255,0.55);
  background: rgba(122,162,255,0.20);
  text-decoration:none;
}
.btn.ghost{
  background: transparent;
  border-color: var(--border);
}
.btn.ghost:hover{
  background: rgba(255,255,255,0.06);
}

.controls{
  display:flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items:flex-end;
  margin: 10px 0 6px;
}
label{ display:flex; flex-direction: column; gap: 6px; font-weight: 700; font-size: 0.95rem; }
label.inline{ min-width: 120px; }
label.check{
  flex-direction: row;
  align-items:center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.04);
}

select, input[type="number"]{
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.10);
  color: var(--text);
}
html[data-theme="light"] select,
html[data-theme="light"] input[type="number"]{
  background: rgba(10,20,40,0.03);
}

.quiz-area{
  margin-top: 14px;
  border-top: 1px dashed var(--border);
  padding-top: 14px;
}
.quiz-top{
  display:flex;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
}
.pill{
  display:inline-flex;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.04);
  font-weight: 800;
}

.prompt{
  font-size: clamp(1.6rem, 3.3vw, 2.2rem);
  font-weight: 900;
  margin: 14px 0 12px;
  letter-spacing: 0.2px;
}

.options{
  display:grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 10px;
}
.option{
  padding: 12px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.04);
  color: var(--text);
  cursor:pointer;
  font-size: 1.1rem;
  font-weight: 800;
  transition: transform 90ms ease, border-color 90ms ease;
}
.option:hover{ transform: translateY(-1px); border-color: rgba(122,162,255,0.45); }
.option:disabled{ opacity: 0.88; cursor: not-allowed; }
.option.correct{
  border-color: rgba(78,229,154,0.65);
  background: rgba(78,229,154,0.14);
}
.option.wrong{
  border-color: rgba(255,107,107,0.65);
  background: rgba(255,107,107,0.14);
}

.feedback{
  margin-top: 12px;
  font-weight: 900;
}
.nav-row{
  display:flex;
  gap: 10px;
  margin-top: 12px;
  flex-wrap: wrap;
}

.summary{
  cursor: pointer;
  font-weight: 900;
}
.study-table{
  width: 100%;
  border-collapse: collapse;
  margin-top: 12px;
  overflow: hidden;
  border-radius: 14px;
  border: 1px solid var(--border);
}
.study-table th, .study-table td{
  padding: 10px 10px;
  border-bottom: 1px solid var(--border);
}
.study-table th{
  text-align:left;
  background: rgba(255,255,255,0.05);
}
.study-table td.hanzi{
  font-size: 1.15rem;
  font-weight: 900;
}

.reading-head{
  display:flex;
  align-items:flex-start;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.reading-text{
  margin-top: 10px;
  padding: 14px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.08);
}
html[data-theme="light"] .reading-text{ background: rgba(10,20,40,0.03); }

.read-line{
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}
.read-line:last-child{ border-bottom: none; }

.read-line .zh{
  font-size: 1.12rem;
  font-weight: 800;
}
.read-line .en{
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.98rem;
  font-weight: 600;
}
/* Flashcards */
.flash-area{
  margin-top: 12px;
  border-top: 1px dashed var(--border);
  padding-top: 14px;
}

.flashcard{
  width: 100%;
  min-height: 160px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.04);
  color: var(--text);
  cursor: pointer;
  box-shadow: var(--shadow);
  display: grid;
  place-items: center;
  padding: 18px;
  transition: transform 120ms ease, border-color 120ms ease;
}

.flashcard:hover{
  transform: translateY(-1px);
  border-color: rgba(122,162,255,0.45);
}

.flash-face{
  text-align: center;
  font-weight: 900;
  font-size: clamp(1.4rem, 3vw, 2.2rem);
  letter-spacing: 0.2px;
  line-height: 1.25;
  white-space: pre-wrap;
}

.flash-sub{
  margin-top: 10px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--muted);
}

.flashcard.is-back{
  border-color: rgba(78,229,154,0.55);
  background: rgba(78,229,154,0.10);
}

/* Audio buttons */
.audio-btn{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: 50%;
  border: 1px solid rgba(122,162,255,0.35);
  background: rgba(122,162,255,0.12);
  color: var(--text);
  cursor: pointer;
  font-size: 1.2rem;
  transition: all 120ms ease;
}

.audio-btn:hover{
  border-color: rgba(122,162,255,0.55);
  background: rgba(122,162,255,0.20);
  transform: scale(1.05);
}

.audio-btn:active{
  transform: scale(0.95);
}

.prompt-area{
  display: flex;
  align-items: center;
  gap: 12px;
  justify-content: space-between;
  flex-wrap: wrap;
}

.flash-audio{
  display: flex;
  justify-content: center;
  margin-top: 12px;
}

.audio-cell{
  text-align: center;
}

/* Video section */
.video-container{
  margin-top: 12px;
}

.week-video{
  width: 100%;
  max-width: 800px;
  height: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  background: rgba(0,0,0,0.1);
}

.video-info{
  margin-top: 8px;
  text-align: center;
}