:root {
  --taxi-yellow: #f8c72e;
  --taxi-gold: #c88718;
  --ink: #17130b;
  --deep-green: #153d36;
  --cream: #fff8e5;
  --paper: #fffdf5;
  --line: rgba(23, 19, 11, 0.16);
  --muted: #6e6048;
  --danger: #b63827;
  --success: #17754f;
  --shadow: 0 24px 70px rgba(23, 19, 11, 0.18);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "Noto Serif TC", "Source Han Serif TC", "PMingLiU", serif;
  min-height: 100vh;
  background:
    radial-gradient(circle at 18% 12%, rgba(248, 199, 46, 0.72), transparent 28rem),
    radial-gradient(circle at 88% 8%, rgba(21, 61, 54, 0.2), transparent 24rem),
    linear-gradient(135deg, #fff6cf 0%, #f5e3b5 42%, #e8c77e 100%);
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  content: "";
  background-image:
    linear-gradient(45deg, rgba(23, 19, 11, 0.05) 25%, transparent 25%),
    linear-gradient(-45deg, rgba(23, 19, 11, 0.05) 25%, transparent 25%);
  background-position: 0 0, 0 12px;
  background-size: 24px 24px;
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.35), transparent 72%);
}

#app {
  width: min(1080px, calc(100% - 24px));
  margin: 0 auto;
  padding: 20px 0 90px;
}

#install-banner {
  position: sticky;
  top: 0;
  z-index: 80;
  margin-bottom: 14px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--cream);
  background: linear-gradient(120deg, var(--ink), var(--deep-green));
  display: flex;
  gap: 8px;
  align-items: center;
  justify-content: flex-end;
  box-shadow: var(--shadow);
}

.hidden {
  display: none !important;
}

#install-btn,
#dismiss-btn {
  min-height: 38px;
  border-radius: 999px;
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-weight: 800;
  cursor: pointer;
}

#install-btn {
  padding: 0 16px;
  border: 0;
  color: var(--ink);
  background: var(--taxi-yellow);
}

#dismiss-btn {
  padding: 0 14px;
  border: 1px solid rgba(255, 248, 229, 0.5);
  color: var(--cream);
  background: transparent;
}

header,
.hero,
.question-container,
.exam-header,
.wrong-item,
.manage-item,
#wrong-page > h2,
#manage-page > h2 {
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  backdrop-filter: blur(12px);
}

header {
  position: sticky;
  top: 0;
  z-index: 70;
  margin-bottom: 18px;
  padding: 20px;
  border-radius: 28px;
  background: rgba(255, 253, 245, 0.9);
}

header h1 {
  margin: 0 0 14px;
  font-size: clamp(1.4rem, 4vw, 2.1rem);
  letter-spacing: -0.04em;
}

nav {
  display: flex;
  gap: 10px;
  overflow-x: auto;
}

.nav-btn {
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid rgba(23, 19, 11, 0.2);
  border-radius: 999px;
  color: var(--ink);
  background: rgba(255, 248, 229, 0.78);
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-size: 0.9rem;
  font-weight: 800;
  white-space: nowrap;
  cursor: pointer;
}

.nav-btn.active {
  border-color: transparent;
  background: var(--taxi-yellow);
}

.page {
  display: none;
}

.page.active {
  display: block;
  animation: rise-in 320ms ease both;
}

.hero {
  margin-bottom: 18px;
  padding: clamp(22px, 5vw, 40px);
  border-radius: 30px;
  background:
    linear-gradient(115deg, rgba(255, 253, 245, 0.92), rgba(255, 248, 229, 0.72)),
    repeating-linear-gradient(90deg, transparent 0 18px, rgba(248, 199, 46, 0.16) 18px 36px);
}

.hero h2 {
  margin: 0 0 12px;
  font-size: clamp(1.5rem, 4vw, 2.2rem);
}

.hero p {
  margin: 6px 0;
  color: var(--muted);
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}

.action-cards {
  display: grid;
  gap: 12px;
  grid-template-columns: 1fr;
}

.card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 22px;
  color: var(--ink);
  background: rgba(255, 253, 245, 0.85);
  text-align: left;
  cursor: pointer;
}

.card .icon {
  display: inline-grid;
  width: 42px;
  height: 42px;
  place-items: center;
  margin-bottom: 8px;
  border-radius: 50%;
  color: var(--cream);
  background: var(--deep-green);
  font-size: 18px;
}

.card h3 {
  margin: 0 0 4px;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}

.install-card {
  border-color: rgba(76, 175, 80, 0.4);
}

.install-card .icon {
  background: var(--taxi-gold);
}

.question-container,
.exam-header,
.wrong-item,
.manage-item {
  border-radius: 26px;
  background: rgba(255, 253, 245, 0.9);
}

.question-container {
  padding: 22px;
}

.progress-bar span,
.exam-progress,
#wrong-list-info,
.manage-item .meta,
.wrong-item .category {
  color: var(--muted);
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}

.bar {
  height: 10px;
  border-radius: 999px;
  background: rgba(23, 19, 11, 0.12);
  overflow: hidden;
}

#progress-fill {
  height: 100%;
  width: 0;
  background: var(--deep-green);
}

.category-tag {
  display: inline-block;
  margin-bottom: 12px;
  padding: 6px 12px;
  border-radius: 999px;
  color: var(--cream);
  background: var(--ink);
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-size: 0.78rem;
  font-weight: 800;
}

.question-text {
  margin-bottom: 16px;
  font-size: 1.08rem;
  line-height: 1.8;
}

.options {
  display: grid;
  gap: 10px;
}

.option {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 13px 14px;
  border: 1px solid var(--line);
  border-radius: 16px;
  color: var(--ink);
  background: rgba(255, 248, 229, 0.58);
  text-align: left;
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  cursor: pointer;
}

.option-label {
  flex: 0 0 30px;
  display: inline-grid;
  place-items: center;
  min-height: 30px;
  border-radius: 999px;
  color: var(--cream);
  background: var(--deep-green);
  font-size: 0.9rem;
  font-weight: 900;
  line-height: 1;
}

.option-text {
  flex: 1;
  min-width: 0;
  line-height: 1.6;
}

.option:hover,
.option.selected {
  border-color: rgba(21, 61, 54, 0.48);
  background: rgba(248, 199, 46, 0.22);
}

.option.correct {
  border-color: rgba(23, 117, 79, 0.58);
  background: rgba(214, 246, 225, 0.8);
}

.option.wrong {
  border-color: rgba(182, 56, 39, 0.54);
  background: rgba(255, 225, 215, 0.8);
}

.option.disabled {
  opacity: 0.75;
  pointer-events: none;
}

.feedback {
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: 14px;
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-weight: 800;
}

.feedback-title,
.explanation-main,
.explanation-source {
  margin: 0 0 8px;
}

.explanation-main,
.explanation-source {
  color: var(--ink);
  font-weight: 500;
  line-height: 1.7;
}

.explanation-source {
  color: var(--muted);
  font-size: 0.95rem;
}

.feedback.correct {
  color: var(--success);
  background: rgba(23, 117, 79, 0.1);
}

.feedback.wrong {
  color: var(--danger);
  background: rgba(182, 56, 39, 0.1);
}

.explanation-list {
  margin: 10px 0 0;
  padding-left: 18px;
  color: var(--ink);
  font-weight: 500;
  line-height: 1.6;
}

.explanation-list li {
  margin-bottom: 6px;
}

.actions,
.manage-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.actions {
  justify-content: flex-end;
}

.btn {
  min-height: 46px;
  padding: 0 20px;
  border-radius: 999px;
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-size: 0.92rem;
  font-weight: 900;
  border: 1px solid rgba(23, 19, 11, 0.2);
  cursor: pointer;
}

.btn.primary,
.btn.success {
  border-color: transparent;
  color: var(--ink);
  background: var(--taxi-yellow);
}

.btn.secondary {
  color: var(--ink);
  background: rgba(255, 253, 245, 0.92);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.exam-header {
  display: flex;
  gap: 14px;
  justify-content: space-between;
  margin-bottom: 14px;
  padding: 16px;
}

.exam-rule {
  margin: 0 0 12px;
  color: var(--muted);
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-size: 0.95rem;
}

.timer {
  display: flex;
  gap: 8px;
  align-items: center;
  color: var(--deep-green);
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-size: 1.1rem;
  font-weight: 900;
}

.timer.warning {
  color: var(--danger);
  animation: pulse 1s infinite;
}

.wrong-list,
.question-list {
  display: grid;
  gap: 10px;
  margin: 14px 0;
}

.wrong-item,
.manage-item {
  padding: 14px;
}

.review-item {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 14px;
  margin-bottom: 12px;
  background: rgba(255, 248, 229, 0.52);
}

.wrong-item .question,
.manage-item h4 {
  margin: 0 0 6px;
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.55; }
}

.manage-item .meta {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
}

.btn-delete {
  margin-left: auto;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 1px solid rgba(182, 56, 39, 0.4);
  color: var(--danger);
  background: transparent;
  font-size: 0.85rem;
  line-height: 1;
  cursor: pointer;
  flex-shrink: 0;
}

.btn-delete:hover {
  background: rgba(182, 56, 39, 0.12);
}

@media (min-width: 860px) {
  .action-cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .question-container {
    padding: 28px;
  }
}

@media (max-width: 640px) {
  #app {
    width: min(100% - 14px, 1080px);
  }

  header,
  .hero,
  .question-container,
  .exam-header {
    border-radius: 20px;
  }

  .exam-header {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    width: 100%;
  }
}

.site-footer {
  margin-top: 40px;
  padding: 20px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-size: 0.85rem;
  text-align: center;
  line-height: 1.8;
}

.site-footer a {
  color: var(--deep-green);
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}