:root {
  --bg-deep: #0a0a0f;
  --bg-card: #12121a;
  --bg-hover: #1a1a28;
  --accent-red: #c41e3a;
  --accent-gold: #c9a227;
  --accent-green: #2d6a4f;
  --accent-celadon: #7eb09b;
  --text-primary: #e8e4dc;
  --text-muted: #8a8698;
  --text-dim: #5c5868;
  --border: rgba(201, 162, 39, 0.15);
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "SimSun", serif;
  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  background: var(--bg-deep);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(196, 30, 58, 0.12), transparent),
    radial-gradient(ellipse 60% 40% at 100% 100%, rgba(45, 106, 79, 0.08), transparent),
    radial-gradient(ellipse 50% 30% at 0% 80%, rgba(201, 162, 39, 0.06), transparent);
  pointer-events: none;
  z-index: 0;
}

.noise {
  position: fixed;
  inset: 0;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 0;
}

.app {
  position: relative;
  z-index: 1;
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
  min-height: 100vh;
}

/* Header */
.header {
  text-align: center;
  margin-bottom: 2.5rem;
  animation: fadeDown 0.8s ease;
}

.header-tag {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--accent-gold);
  border: 1px solid var(--border);
  padding: 0.35rem 1rem;
  margin-bottom: 1rem;
}

.header h1 {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 6vw, 3rem);
  font-weight: 700;
  letter-spacing: 0.15em;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-celadon) 50%, var(--accent-gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

.header-sub {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.header-quote {
  margin-top: 1.25rem;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.8;
}

/* Screens */
.screen {
  display: none;
  animation: fadeIn 0.5s ease;
}

.screen.active {
  display: block;
}

/* Start screen */
.start-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 2rem;
  box-shadow: var(--shadow);
}

.start-stats {
  display: flex;
  justify-content: center;
  margin-bottom: 2rem;
}

.stat-item {
  text-align: center;
  padding: 1rem 1.5rem;
  min-width: 8rem;
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 2px;
}

.stat-num {
  font-family: var(--font-serif);
  font-size: 1.75rem;
  color: var(--accent-gold);
  font-weight: 700;
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.start-desc {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
  line-height: 1.8;
}

.mode-select {
  margin-bottom: 1.5rem;
}

.mode-select label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-bottom: 0.5rem;
  letter-spacing: 0.05em;
}

.character-options {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.6rem;
  margin-bottom: 1.25rem;
}

.character-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 0.85rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 2px;
  cursor: pointer;
  text-align: center;
  transition: all 0.2s;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

.character-btn:hover {
  border-color: var(--accent-celadon);
  background: var(--bg-hover);
}

.character-btn.selected {
  border-color: var(--accent-gold);
  background: rgba(201, 162, 39, 0.1);
}

.character-options .character-btn:first-child {
  grid-column: 1 / -1;
}

.difficulty-options {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.6rem;
  margin-bottom: 1.25rem;
}

.difficulty-btn {
  padding: 0.75rem 0.85rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 2px;
  cursor: pointer;
  text-align: center;
  transition: all 0.2s;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

.difficulty-btn:hover {
  border-color: var(--accent-celadon);
  background: var(--bg-hover);
}

.difficulty-btn.selected {
  border-color: var(--accent-gold);
  background: rgba(201, 162, 39, 0.1);
}

.mode-options {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.mode-btn {
  flex: 1;
  min-width: 120px;
  padding: 0.65rem 1rem;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  cursor: pointer;
  border-radius: 2px;
  transition: all 0.2s;
}

.mode-btn:hover {
  border-color: var(--accent-gold);
  color: var(--text-primary);
}

.mode-btn.selected {
  background: rgba(201, 162, 39, 0.12);
  border-color: var(--accent-gold);
  color: var(--accent-gold);
}

.custom-panel {
  margin-bottom: 1.5rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  overflow: hidden;
}

.custom-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 0.85rem 1rem;
  background: rgba(255, 255, 255, 0.02);
  border: none;
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s;
}

.custom-toggle:hover {
  background: var(--bg-hover);
}

.custom-badge {
  min-width: 1.5rem;
  padding: 0.1rem 0.45rem;
  border-radius: 999px;
  background: rgba(201, 162, 39, 0.15);
  color: var(--accent-gold);
  font-size: 0.75rem;
  text-align: center;
}

.custom-body {
  padding: 0 1rem 1rem;
  border-top: 1px solid var(--border);
}

.custom-hint {
  margin: 0.85rem 0 1rem;
  font-size: 0.78rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.custom-form {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.custom-field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.custom-field-full {
  grid-column: 1 / -1;
}

.custom-field span {
  font-size: 0.75rem;
  color: var(--text-dim);
}

.custom-field input,
.custom-field select,
.custom-field textarea {
  width: 100%;
  padding: 0.55rem 0.65rem;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--border);
  border-radius: 2px;
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.85rem;
}

.custom-field textarea {
  resize: vertical;
  min-height: 3rem;
}

.custom-options-grid,
.custom-meta-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.65rem;
}

.custom-error {
  margin: 0;
  font-size: 0.78rem;
  color: #e8a0a0;
}

.btn-custom-add {
  width: 100%;
  padding: 0.7rem 1rem;
  background: rgba(201, 162, 39, 0.12);
  border: 1px solid rgba(201, 162, 39, 0.45);
  color: var(--accent-gold);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  border-radius: 2px;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-custom-add:hover {
  background: rgba(201, 162, 39, 0.2);
}

.custom-list-wrap {
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.custom-list-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.65rem;
  font-size: 0.78rem;
  color: var(--text-dim);
}

.custom-clear-btn,
.custom-refresh-btn {
  background: none;
  border: none;
  color: var(--accent-celadon);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  cursor: pointer;
  padding: 0;
}

.custom-clear-btn:hover,
.custom-refresh-btn:hover {
  color: var(--text-primary);
}

.custom-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-height: 12rem;
  overflow-y: auto;
}

.custom-item {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  padding: 0.6rem 0.65rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border);
  border-radius: 2px;
}

.custom-item-text {
  flex: 1;
  min-width: 0;
}

.custom-item-q {
  display: block;
  font-size: 0.82rem;
  color: var(--text-primary);
  line-height: 1.45;
  word-break: break-word;
}

.custom-item-meta {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.7rem;
  color: var(--text-muted);
}

.custom-delete-btn {
  display: none;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 2rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  border: none;
  border-radius: 2px;
  cursor: pointer;
  transition: all 0.25s;
  width: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-red) 0%, #8b1528 100%);
  color: #fff;
  box-shadow: 0 4px 20px rgba(196, 30, 58, 0.3);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 28px rgba(196, 30, 58, 0.45);
}

.btn-secondary {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-muted);
  margin-top: 0.75rem;
}

.btn-secondary:hover {
  border-color: var(--accent-celadon);
  color: var(--text-primary);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none !important;
}

/* Quiz screen */
.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.quiz-progress-bar {
  height: 3px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 2px;
  margin-bottom: 2rem;
  overflow: hidden;
}

.quiz-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-red), var(--accent-gold));
  border-radius: 2px;
  transition: width 0.4s ease;
  width: 0%;
}

.question-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 2rem;
  box-shadow: var(--shadow);
}

.question-text {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  line-height: 1.7;
  margin-bottom: 1.75rem;
}

.options-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.option-btn {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  width: 100%;
  padding: 1rem 1.25rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 2px;
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  text-align: left;
  cursor: pointer;
  transition: all 0.2s;
  line-height: 1.5;
}

.option-btn:hover:not(:disabled) {
  background: var(--bg-hover);
  border-color: rgba(201, 162, 39, 0.3);
}

.option-btn:disabled {
  cursor: default;
}

.option-letter {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: 2px;
  color: var(--accent-gold);
}

.option-btn.correct {
  background: rgba(45, 106, 79, 0.2);
  border-color: var(--accent-green);
}

.option-btn.correct .option-letter {
  background: var(--accent-green);
  border-color: var(--accent-green);
  color: #fff;
}

.option-btn.wrong {
  background: rgba(196, 30, 58, 0.15);
  border-color: var(--accent-red);
}

.option-btn.wrong .option-letter {
  background: var(--accent-red);
  border-color: var(--accent-red);
  color: #fff;
}

.option-btn.dimmed {
  opacity: 0.35;
}

.explanation-box {
  margin-top: 1.5rem;
  padding: 1rem 1.25rem;
  background: rgba(201, 162, 39, 0.06);
  border-left: 3px solid var(--accent-gold);
  border-radius: 0 2px 2px 0;
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.7;
  display: none;
  animation: fadeIn 0.3s ease;
}

.explanation-box.show {
  display: block;
}

.explanation-box strong {
  color: var(--accent-gold);
  font-weight: 500;
}

.rating-panel {
  margin-top: 1.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
  animation: fadeIn 0.25s ease;
}

.rating-panel[hidden] {
  display: none;
}

.rating-label {
  font-size: 0.9rem;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.rating-options {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.4rem;
}

.rating-btn {
  min-width: 0;
  padding: 0.65rem 0.35rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
  border-radius: 2px;
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 500;
  line-height: 1.25;
  cursor: pointer;
  transition: all 0.15s;
  text-align: center;
}

.rating-btn:hover {
  border-color: var(--accent-gold);
  color: var(--accent-gold);
  background: rgba(201, 162, 39, 0.1);
}

.rating-btn:disabled {
  cursor: default;
  opacity: 0.55;
}

.rating-btn.selected {
  border-color: var(--accent-gold);
  color: var(--accent-gold);
  background: rgba(201, 162, 39, 0.16);
}

.rating-hint {
  margin-top: 0.6rem;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.rating-unsuitable-btn {
  display: block;
  width: fit-content;
  margin: 1.25rem auto 0;
  padding: 0.45rem 1rem;
  background: transparent;
  border: 1px solid rgba(180, 90, 90, 0.45);
  border-radius: 2px;
  color: rgba(220, 140, 140, 0.95);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
}

.rating-unsuitable-btn:hover {
  border-color: rgba(220, 120, 120, 0.8);
  background: rgba(180, 60, 60, 0.12);
  color: #e8a0a0;
}

.rating-unsuitable-btn:disabled {
  cursor: default;
  opacity: 0.55;
}

.rating-unsuitable-btn.selected {
  border-color: rgba(220, 120, 120, 0.9);
  background: rgba(180, 60, 60, 0.18);
  color: #eec0c0;
}

.quiz-actions {
  margin-top: 1.5rem;
}

/* Results */
.results-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 2.5rem 2rem;
  text-align: center;
  box-shadow: var(--shadow);
}

.results-score {
  font-family: var(--font-serif);
  font-size: 4rem;
  font-weight: 700;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.results-score.good {
  color: var(--accent-gold);
}

.results-score.mid {
  color: var(--accent-celadon);
}

.results-score.low {
  color: var(--accent-red);
}

.results-label {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.results-title {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  margin: 1.5rem 0 0.5rem;
}

.results-desc {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.8;
  margin-bottom: 1rem;
}

.results-rank {
  display: inline-block;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.55rem 1rem;
  margin-bottom: 2rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  color: var(--text-muted);
}

.results-rank.loading {
  opacity: 0.7;
}

.results-rank.first {
  color: var(--accent-celadon);
  border-color: rgba(143, 188, 167, 0.35);
}

.results-rank.high {
  color: var(--accent-gold);
  border-color: rgba(212, 175, 95, 0.4);
  background: rgba(212, 175, 95, 0.08);
}

.results-rank.mid {
  color: var(--accent-celadon);
  border-color: rgba(143, 188, 167, 0.35);
}

.results-rank.low {
  color: var(--text-muted);
}

.results-breakdown {
  text-align: left;
  margin-bottom: 2rem;
  max-height: 300px;
  overflow-y: auto;
}

.breakdown-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
  font-size: 0.85rem;
}

.breakdown-icon {
  flex-shrink: 0;
  width: 20px;
  text-align: center;
}

.breakdown-icon.correct {
  color: var(--accent-green);
}

.breakdown-icon.wrong {
  color: var(--accent-red);
}

.breakdown-text {
  color: var(--text-muted);
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.breakdown-diff {
  color: var(--accent-gold);
  font-size: 0.8em;
  margin-left: 0.35rem;
}

.results-actions {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeDown {
  from { opacity: 0; transform: translateY(-12px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 480px) {
  .character-options {
    grid-template-columns: 1fr;
  }

  .difficulty-options {
    grid-template-columns: 1fr;
  }

  .character-options .character-btn:first-child {
    grid-column: auto;
  }

  .question-card {
    padding: 1.5rem;
  }

  .question-text {
    font-size: 1.1rem;
  }

  .rating-options {
    grid-template-columns: repeat(3, 1fr);
  }

  .rating-btn {
    font-size: 0.68rem;
    padding: 0.6rem 0.25rem;
  }
}