/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #0f172a;
  --bg2: #1e293b;
  --bg3: #273548;
  --border: #334155;
  --text: #f1f5f9;
  --text2: #94a3b8;
  --text3: #64748b;
  --blue: #3b82f6;
  --blue-dark: #2563eb;
  --green: #22c55e;
  --green-dark: #16a34a;
  --red: #ef4444;
  --red-dark: #dc2626;
  --purple: #a855f7;
  --purple-dark: #9333ea;
  --yellow: #eab308;
  --radius: 10px;
  --shadow: 0 4px 24px rgba(0,0,0,0.4);
}

html, body { height: 100%; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang TC', 'Microsoft JhengHei', sans-serif;
  font-size: 15px;
  line-height: 1.6;
  min-height: 100vh;
}

#app { min-height: 100vh; display: flex; flex-direction: column; }

/* ===== Layout ===== */
.page { display: none; flex: 1; }
.page.active { display: flex; flex-direction: column; }

.container { max-width: 680px; width: 100%; margin: 0 auto; padding: 0 16px; }

/* ===== Navbar ===== */
.navbar {
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
  padding: 0 16px;
  position: sticky;
  top: 0;
  z-index: 100;
}
.navbar-inner {
  max-width: 680px;
  margin: 0 auto;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.navbar-brand { font-size: 18px; font-weight: 700; color: var(--text); text-decoration: none; cursor: pointer; }
.navbar-brand span { color: var(--blue); }
.navbar-actions { display: flex; gap: 8px; align-items: center; }
.nav-user { color: var(--text2); font-size: 13px; }
.nav-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text2);
  padding: 5px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  transition: all 0.15s;
}
.nav-btn:hover { border-color: var(--blue); color: var(--text); }

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  transition: all 0.15s;
  text-decoration: none;
}
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-primary { background: var(--blue); color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--blue-dark); }
.btn-success { background: var(--green); color: #fff; }
.btn-success:hover:not(:disabled) { background: var(--green-dark); }
.btn-danger { background: var(--red); color: #fff; }
.btn-danger:hover:not(:disabled) { background: var(--red-dark); }
.btn-purple { background: var(--purple); color: #fff; }
.btn-purple:hover:not(:disabled) { background: var(--purple-dark); }
.btn-ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text2);
}
.btn-ghost:hover:not(:disabled) { border-color: var(--blue); color: var(--text); }
.btn-full { width: 100%; }
.btn-sm { padding: 6px 12px; font-size: 13px; }

/* ===== Cards ===== */
.card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}
.card-sm { padding: 14px 16px; }

/* ===== Forms ===== */
.form-group { margin-bottom: 16px; }
.form-label { display: block; font-size: 13px; color: var(--text2); margin-bottom: 6px; font-weight: 500; }
.form-input, .form-textarea, .form-select {
  width: 100%;
  background: var(--bg3);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  padding: 10px 14px;
  font-size: 14px;
  font-family: inherit;
  transition: border-color 0.15s;
  outline: none;
}
.form-input:focus, .form-textarea:focus, .form-select:focus {
  border-color: var(--blue);
}
.form-input::placeholder, .form-textarea::placeholder { color: var(--text3); }
.form-textarea { resize: vertical; min-height: 160px; font-size: 13px; line-height: 1.7; }
.form-hint { font-size: 12px; color: var(--text3); margin-top: 5px; }
.form-error { font-size: 12px; color: var(--red); margin-top: 5px; }

/* ===== Auth Page ===== */
#page-auth {
  justify-content: center;
  align-items: center;
  padding: 24px 16px;
  min-height: 100vh;
}
.auth-box { width: 100%; max-width: 400px; }
.auth-logo { text-align: center; margin-bottom: 28px; }
.auth-logo h1 { font-size: 26px; font-weight: 800; }
.auth-logo h1 span { color: var(--blue); }
.auth-logo p { color: var(--text2); font-size: 13px; margin-top: 4px; }
.auth-tabs { display: flex; margin-bottom: 20px; border-radius: 8px; overflow: hidden; border: 1px solid var(--border); }
.auth-tab {
  flex: 1; padding: 10px; text-align: center; cursor: pointer;
  background: transparent; color: var(--text2); font-size: 14px; font-weight: 600;
  border: none; transition: all 0.15s;
}
.auth-tab.active { background: var(--blue); color: #fff; }
.auth-msg {
  text-align: center; padding: 10px; border-radius: 8px;
  font-size: 13px; margin-bottom: 12px; display: none;
}
.auth-msg.error { background: rgba(239,68,68,0.15); color: #fca5a5; border: 1px solid rgba(239,68,68,0.3); display: block; }
.auth-msg.success { background: rgba(34,197,94,0.15); color: #86efac; border: 1px solid rgba(34,197,94,0.3); display: block; }

/* ===== Home Page ===== */
#page-home { padding: 24px 0; }
.home-hero {
  text-align: center;
  padding: 32px 16px 24px;
}
.home-hero h2 { font-size: 28px; font-weight: 800; margin-bottom: 8px; }
.home-hero p { color: var(--text2); font-size: 15px; }
.home-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 20px 16px; }
.stat-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s;
}
.stat-card:hover { border-color: var(--blue); }
.stat-num { font-size: 32px; font-weight: 800; color: var(--blue); }
.stat-label { font-size: 13px; color: var(--text2); margin-top: 4px; }
.home-actions { display: flex; flex-direction: column; gap: 10px; padding: 0 16px 24px; }

/* ===== Banks Page ===== */
#page-banks { padding: 20px 0; }
.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  margin-bottom: 20px;
}
.page-title { font-size: 20px; font-weight: 700; }
.bank-list { display: flex; flex-direction: column; gap: 10px; padding: 0 16px; }
.bank-card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
}
.bank-card-top { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 6px; }
.bank-name { font-size: 16px; font-weight: 600; }
.bank-meta { font-size: 12px; color: var(--text3); margin-bottom: 4px; display: flex; align-items: center; gap: 6px; }
.bank-preview { font-size: 12px; color: var(--text2); margin-bottom: 10px; }
.bank-actions { display: flex; gap: 8px; }

/* ===== Create Bank Page ===== */
#page-create-bank, #page-edit-bank { padding: 20px 0; }
.bank-counter { text-align: right; font-size: 12px; color: var(--text3); margin-bottom: 4px; }

/* ===== Setup Page ===== */
#page-setup { padding: 24px 0; }
.bank-option {
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  cursor: pointer;
  margin-bottom: 10px;
  transition: border-color 0.15s;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.bank-option:hover { border-color: var(--blue); }
.bank-option.selected { border-color: var(--blue); background: rgba(59,130,246,0.08); }
.bank-option-left { display: flex; align-items: center; gap: 10px; }
.bank-option-radio {
  width: 18px; height: 18px; border-radius: 50%;
  border: 2px solid var(--border); flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
}
.bank-option.selected .bank-option-radio { border-color: var(--blue); }
.bank-option.selected .bank-option-radio::after {
  content: ''; width: 9px; height: 9px;
  background: var(--blue); border-radius: 50%;
}
.bank-option-name { font-size: 14px; font-weight: 600; }
.bank-option-count { font-size: 12px; color: var(--text3); }
.num-input-row { display: flex; align-items: center; gap: 12px; }
.num-input-row .form-input { flex: 1; }

/* ===== Quiz Page ===== */
#page-quiz { padding: 20px 0; }
.quiz-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  margin-bottom: 20px;
}
.quiz-progress-text { font-size: 15px; font-weight: 600; color: var(--text2); }
.quiz-score { display: flex; align-items: center; gap: 5px; font-size: 15px; font-weight: 600; color: var(--yellow); }
.quiz-progress-bar {
  height: 4px;
  background: var(--bg3);
  border-radius: 2px;
  margin: 0 16px 20px;
  overflow: hidden;
}
.quiz-progress-fill { height: 100%; background: var(--blue); border-radius: 2px; transition: width 0.3s; }
.quiz-card { margin: 0 16px 16px; }
.quiz-chinese { font-size: 28px; font-weight: 800; margin-bottom: 8px; text-align: center; }
.quiz-hint { font-size: 14px; color: var(--blue); text-align: center; margin-bottom: 20px; }
.quiz-inputs { display: flex; flex-direction: column; gap: 12px; margin-bottom: 16px; }
.quiz-input-group { position: relative; }
.quiz-input-label { font-size: 12px; color: var(--text3); margin-bottom: 4px; }
.quiz-input {
  width: 100%; background: var(--bg3); border: 1.5px solid var(--border);
  border-radius: 8px; color: var(--text); padding: 12px 14px;
  font-size: 15px; font-family: inherit; outline: none; transition: border-color 0.15s;
}
.quiz-input:focus { border-color: var(--blue); }
.quiz-input.correct { border-color: var(--green); background: rgba(34,197,94,0.08); }
.quiz-input.wrong { border-color: var(--red); background: rgba(239,68,68,0.08); }
.quiz-answer-hint { font-size: 12px; margin-top: 4px; }
.quiz-answer-hint.correct { color: var(--green); }
.quiz-answer-hint.wrong { color: var(--red); }

/* ===== Results Page ===== */
#page-results { padding: 24px 0; }
.results-score-big {
  text-align: center; padding: 28px 16px 20px;
}
.results-score-big .score-num { font-size: 64px; font-weight: 900; color: var(--blue); line-height: 1; }
.results-score-big .score-label { color: var(--text2); font-size: 15px; margin-top: 8px; }
.results-list { padding: 0 16px; margin-bottom: 20px; }
.result-item {
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: 8px; padding: 12px 14px; margin-bottom: 8px;
}
.result-item.correct { border-left: 3px solid var(--green); }
.result-item.wrong { border-left: 3px solid var(--red); }
.result-item-chinese { font-size: 16px; font-weight: 700; margin-bottom: 4px; }
.result-item-forms { font-size: 13px; color: var(--text2); }
.result-item-forms span { color: var(--text); font-family: monospace; }
.result-item-wrong-detail { font-size: 12px; color: var(--red); margin-top: 4px; }
.results-actions { display: flex; flex-direction: column; gap: 10px; padding: 0 16px 24px; }

/* ===== Wrong Answers Page ===== */
#page-wrong { padding: 20px 0; }
.wrong-item {
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: 8px; padding: 12px 14px;
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 8px;
}
.wrong-item-left {}
.wrong-item-chinese { font-size: 15px; font-weight: 600; }
.wrong-item-forms { font-size: 12px; color: var(--text2); font-family: monospace; margin-top: 2px; }
.wrong-item-right { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.wrong-count-badge {
  background: rgba(239,68,68,0.2); color: #fca5a5;
  border: 1px solid rgba(239,68,68,0.3);
  border-radius: 12px; padding: 2px 8px; font-size: 11px; font-weight: 600;
}
.empty-state {
  text-align: center; padding: 48px 16px; color: var(--text3);
}
.empty-state .empty-icon { font-size: 48px; margin-bottom: 12px; }
.empty-state p { font-size: 15px; }

/* ===== Settings Page ===== */
#page-settings { padding: 24px 0; }
.settings-section { margin: 0 16px 24px; }
.settings-title { font-size: 13px; font-weight: 700; color: var(--text3); text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 10px; }
.settings-msg {
  padding: 10px 14px; border-radius: 8px; font-size: 13px; margin-bottom: 12px; display: none;
}
.settings-msg.error { background: rgba(239,68,68,0.15); color: #fca5a5; border: 1px solid rgba(239,68,68,0.3); display: block; }
.settings-msg.success { background: rgba(34,197,94,0.15); color: #86efac; border: 1px solid rgba(34,197,94,0.3); display: block; }

/* ===== Toast ===== */
#toast {
  position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%) translateY(80px);
  background: var(--bg2); border: 1px solid var(--border);
  color: var(--text); padding: 12px 20px; border-radius: 10px;
  font-size: 14px; font-weight: 500; z-index: 1000;
  transition: transform 0.3s ease; box-shadow: var(--shadow);
  white-space: nowrap; pointer-events: none;
}
#toast.show { transform: translateX(-50%) translateY(0); }
#toast.success { border-color: var(--green); color: var(--green); }
#toast.error { border-color: var(--red); color: var(--red); }

/* ===== Modal ===== */
.modal-overlay {
  position: fixed; inset: 0; background: rgba(0,0,0,0.6);
  display: none; align-items: center; justify-content: center;
  z-index: 200; padding: 16px;
}
.modal-overlay.show { display: flex; }
.modal-box {
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: 14px; padding: 24px; width: 100%; max-width: 400px;
  box-shadow: var(--shadow);
}
.modal-title { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.modal-text { color: var(--text2); font-size: 14px; margin-bottom: 20px; }
.modal-actions { display: flex; gap: 10px; }
.modal-actions .btn { flex: 1; }

/* ===== Loading ===== */
.loading-spinner {
  display: flex; align-items: center; justify-content: center;
  padding: 48px; color: var(--text3); gap: 10px;
}
.spinner {
  width: 20px; height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--blue);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ===== Badges ===== */
.badge {
  display: inline-block; padding: 2px 8px; border-radius: 12px;
  font-size: 11px; font-weight: 600;
}
.badge-blue { background: rgba(59,130,246,0.2); color: #93c5fd; border: 1px solid rgba(59,130,246,0.3); }
.badge-green { background: rgba(34,197,94,0.2); color: #86efac; border: 1px solid rgba(34,197,94,0.3); }

/* ===== Section title ===== */
.section-title {
  font-size: 14px; font-weight: 700; color: var(--text2);
  margin-bottom: 10px; padding: 0 16px;
  display: flex; align-items: center; gap: 6px;
}
.section-title .count-badge {
  background: var(--blue); color: #fff;
  border-radius: 12px; padding: 0 7px; font-size: 12px;
}

/* ===== Responsive ===== */
@media (max-width: 480px) {
  .home-grid { grid-template-columns: 1fr 1fr; gap: 8px; }
  .quiz-chinese { font-size: 24px; }
  .bank-actions { flex-wrap: wrap; }
  .bank-actions .btn { flex: 1; min-width: 80px; }
}