:root {
  --bg: #0f172a;
  --surface: #1e293b;
  --surface-2: #334155;
  --text: #f1f5f9;
  --text-dim: #94a3b8;
  --accent: #4f46e5;
  --accent-2: #818cf8;
  --danger: #ef4444;
  --success: #22c55e;
  --radius: 14px;
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", sans-serif;
  -webkit-tap-highlight-color: transparent;
}

body {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  padding-bottom: env(safe-area-inset-bottom);
}

header.topbar {
  padding: calc(env(safe-area-inset-top) + 16px) 20px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

header.topbar h1 {
  font-size: 20px;
  margin: 0;
}

main {
  flex: 1;
  padding: 0 16px 16px;
  max-width: 480px;
  width: 100%;
  margin: 0 auto;
}

.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 18px;
  margin-bottom: 14px;
}

label {
  display: block;
  font-size: 13px;
  color: var(--text-dim);
  margin: 12px 0 6px;
}
label:first-child { margin-top: 0; }

input, textarea {
  width: 100%;
  background: var(--surface-2);
  border: 1px solid transparent;
  border-radius: 10px;
  padding: 12px;
  color: var(--text);
  font-size: 16px;
  font-family: inherit;
}
input:focus, textarea:focus {
  outline: none;
  border-color: var(--accent-2);
}

textarea { resize: vertical; min-height: 60px; }

button {
  font-family: inherit;
  font-size: 15px;
  border: none;
  border-radius: 10px;
  padding: 12px 18px;
  cursor: pointer;
}

.btn-primary {
  background: var(--accent);
  color: white;
  width: 100%;
  font-weight: 600;
  padding: 14px;
  font-size: 16px;
}
.btn-primary:active { background: var(--accent-2); }

.btn-secondary {
  background: var(--surface-2);
  color: var(--text);
}

.btn-danger {
  background: transparent;
  color: var(--danger);
}

.btn-ghost {
  background: transparent;
  color: var(--text-dim);
}

.word-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 0;
  border-bottom: 1px solid var(--surface-2);
  gap: 12px;
}
.word-item:last-child { border-bottom: none; }

.word-item .front { font-weight: 600; }
.word-item .back { color: var(--text-dim); font-size: 14px; }
.word-item .meta { font-size: 12px; color: var(--text-dim); margin-top: 2px; }

.word-actions { display: flex; gap: 8px; flex-shrink: 0; }
.word-actions button { padding: 8px 10px; font-size: 13px; }

nav.tabbar {
  display: flex;
  border-top: 1px solid var(--surface-2);
  background: var(--surface);
  padding-bottom: env(safe-area-inset-bottom);
}
nav.tabbar a {
  flex: 1;
  text-align: center;
  padding: 12px 0;
  color: var(--text-dim);
  text-decoration: none;
  font-size: 12px;
  position: relative;
}
nav.tabbar a .icon { display: block; font-size: 20px; margin-bottom: 2px; }
nav.tabbar a.active { color: var(--accent-2); }

.badge {
  position: absolute;
  top: 6px;
  right: calc(50% - 22px);
  background: var(--danger);
  color: white;
  border-radius: 10px;
  font-size: 10px;
  padding: 1px 6px;
  min-width: 16px;
}

.empty-state {
  text-align: center;
  color: var(--text-dim);
  padding: 60px 20px;
}
.empty-state .emoji { font-size: 40px; display: block; margin-bottom: 12px; }

.review-card {
  min-height: 260px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 32px 20px;
  cursor: pointer;
}
.review-card .front-text { font-size: 26px; font-weight: 700; }
.review-card .back-text { font-size: 20px; color: var(--accent-2); margin-top: 18px; }
.review-card .memo-text { font-size: 14px; color: var(--text-dim); margin-top: 10px; }
.review-card .hint { font-size: 12px; color: var(--text-dim); margin-top: 20px; }

.review-progress {
  text-align: center;
  color: var(--text-dim);
  font-size: 13px;
  margin-bottom: 10px;
}

.review-actions {
  display: flex;
  gap: 10px;
}
.review-actions button {
  flex: 1;
  padding: 16px;
  font-size: 16px;
  font-weight: 600;
}
.btn-forgot { background: var(--surface-2); color: var(--text); }
.btn-remember { background: var(--success); color: white; }

.suggest-item {
  background: var(--surface-2);
  border-radius: 10px;
  padding: 14px;
  margin-top: 12px;
}
.suggest-item .front { font-weight: 700; font-size: 17px; }
.suggest-item .reading { font-weight: 400; font-size: 13px; color: var(--text-dim); }
.suggest-item .back { color: var(--accent-2); font-size: 14px; margin-top: 4px; }
.suggest-item .mnemonic { color: var(--text-dim); font-size: 13px; margin-top: 6px; line-height: 1.5; }
.suggest-item .btn-primary { margin-top: 10px; padding: 10px; font-size: 14px; }

.toast {
  position: fixed;
  bottom: 90px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--surface-2);
  color: var(--text);
  padding: 10px 18px;
  border-radius: 20px;
  font-size: 13px;
  opacity: 0;
  transition: opacity 0.2s;
  pointer-events: none;
  z-index: 20;
}
.toast.show { opacity: 1; }

dialog {
  border: none;
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  padding: 20px;
  width: min(90vw, 420px);
}
dialog::backdrop { background: rgba(0,0,0,0.5); }