/* ==========================================================================
   政治理论排坑速练 — 苹果风 / 极简扁平 / 色彩克制
   ========================================================================== */

:root {
  --bg: #f5f5f7;
  --bg-elevated: #ffffff;
  --card: #ffffff;
  --text: #1d1d1f;
  --text-2: #6e6e73;
  --text-3: #8e8e93;
  --line: rgba(0, 0, 0, 0.08);
  --line-strong: rgba(0, 0, 0, 0.14);

  --accent: #0071e3;
  --accent-soft: rgba(0, 113, 227, 0.10);
  --green: #34c759;
  --green-soft: rgba(52, 199, 89, 0.12);
  --red: #ff3b30;
  --red-soft: rgba(255, 59, 48, 0.12);
  --orange: #ff9f0a;
  --orange-soft: rgba(255, 159, 10, 0.14);

  --radius: 20px;
  --radius-md: 14px;
  --radius-sm: 10px;
  --shadow-1: 0 1px 2px rgba(0, 0, 0, 0.04), 0 6px 20px rgba(0, 0, 0, 0.05);
  --shadow-2: 0 2px 6px rgba(0, 0, 0, 0.06), 0 14px 40px rgba(0, 0, 0, 0.09);

  --font: -apple-system, BlinkMacSystemFont, "SF Pro SC", "SF Pro Text",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue",
    Helvetica, Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --bg-elevated: #1c1c1e;
    --card: #1c1c1e;
    --text: #f5f5f7;
    --text-2: #a1a1a6;
    --text-3: #8e8e93;
    --line: rgba(255, 255, 255, 0.10);
    --line-strong: rgba(255, 255, 255, 0.18);
    --accent: #0a84ff;
    --accent-soft: rgba(10, 132, 255, 0.16);
    --green: #30d158;
    --green-soft: rgba(48, 209, 88, 0.16);
    --red: #ff453a;
    --red-soft: rgba(255, 69, 58, 0.16);
    --orange: #ffd60a;
    --orange-soft: rgba(255, 214, 10, 0.16);
    --shadow-1: none;
    --shadow-2: 0 2px 10px rgba(0, 0, 0, 0.5);
  }
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-size-adjust: 100%;
}

button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
svg { display: block; }

.app {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 22px 72px;
  min-height: 100vh;
}

.view { display: none; }
.view.is-active { display: block; animation: fade-in 0.28s ease both; }

@keyframes fade-in {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: none; }
}

/* ---------------------------------------------------------------- 首页 Hero */
.hero { padding: 16px 2px 4px; }

.hero-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
}
.hero-heading { min-width: 0; }

.hero-title {
  margin: 0;
  font-size: 34px;
  line-height: 1.16;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(120deg, var(--text) 30%, var(--text-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-sub {
  margin: 10px 0 0;
  font-size: 15px;
  color: var(--text-2);
  letter-spacing: 0.01em;
}

.hero-stats {
  margin-top: 16px;
  font-size: 13px;
  color: var(--text-3);
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
}
.hero-stats b { color: var(--text-2); font-weight: 600; }

/* ------------------------------------------------------- 题库切换下拉列表 */
.bank-switch {
  position: relative;
  flex: none;
  display: flex;
  align-items: center;
  gap: 8px;
}
/* display:flex 会盖掉 [hidden] 的 display:none，这里补回来 */
.bank-switch[hidden] { display: none; }

.bank-switch-hint {
  font-size: 13px;
  color: var(--text-3);
  letter-spacing: 0.01em;
  white-space: nowrap;
  user-select: none;
}

.bank-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px 8px 14px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 980px;
  box-shadow: var(--shadow-1);
  white-space: nowrap;
  transition: background 0.18s, border-color 0.18s, color 0.18s, transform 0.18s;
}
.bank-btn:hover { border-color: var(--line-strong); }
.bank-btn:active { transform: scale(0.97); }
.bank-btn.is-open {
  color: var(--accent);
  background: var(--accent-soft);
  border-color: transparent;
}
.bank-btn-label {
  max-width: 108px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.bank-caret {
  width: 15px; height: 15px; flex: none;
  opacity: 0.55;
  transition: transform 0.22s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.bank-btn.is-open .bank-caret { transform: rotate(180deg); opacity: 1; }

.bank-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 40;
  width: min(288px, calc(100vw - 40px));
  padding: 6px;
  background: var(--bg-elevated);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.14), 0 2px 8px rgba(0, 0, 0, 0.05);
  transform-origin: top right;
  animation: menu-in 0.2s cubic-bezier(0.2, 0.9, 0.2, 1) both;
}
.bank-menu[hidden] { display: none; }

@keyframes menu-in {
  from { opacity: 0; transform: translateY(-6px) scale(0.97); }
  to { opacity: 1; transform: none; }
}

.bank-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 11px 12px;
  text-align: left;
  border-radius: 11px;
  transition: background 0.16s;
}
.bank-item:hover { background: var(--bg); }

.bank-item-main {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.bank-item-name {
  display: block;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.35;
}
.bank-item-meta { display: block; font-size: 12px; color: var(--text-3); line-height: 1.3; }

.bank-check {
  width: 17px; height: 17px; flex: none;
  color: var(--accent);
  opacity: 0;
  transition: opacity 0.16s;
}
.bank-item.is-on .bank-check { opacity: 1; }
.bank-item.is-on .bank-item-name { color: var(--accent); }

/* ------------------------------------------------------------- 快捷入口卡片 */
.quick-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin: 26px 0 34px;
}

.quick-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
  padding: 18px 18px 16px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
  text-align: left;
  transition: transform 0.22s cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 0.22s;
}
.quick-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-2); }
.quick-card:active { transform: translateY(-1px) scale(0.99); }

.quick-icon {
  width: 38px; height: 38px;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 10px;
}
.quick-icon svg { width: 21px; height: 21px; }
.quick-wrong .quick-icon { background: var(--red-soft); color: var(--red); }
.quick-shuffle .quick-icon { background: var(--accent-soft); color: var(--accent); }

.quick-title { font-size: 17px; font-weight: 600; letter-spacing: -0.01em; }
.quick-desc { font-size: 13px; color: var(--text-2); }

/* ------------------------------------------------------------------ 章节列表 */
.section-title {
  margin: 0 0 12px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-3);
  padding-left: 2px;
}

.chapter-list { display: flex; flex-direction: column; gap: 10px; }

.chapter-item {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  padding: 16px 18px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-1);
  text-align: left;
  transition: transform 0.2s cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 0.2s;
}
.chapter-item:hover { transform: translateY(-2px); box-shadow: var(--shadow-2); }
.chapter-item:active { transform: none; }

.chapter-main { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 4px; }
.chapter-name {
  display: block;
  font-size: 16px; font-weight: 600; letter-spacing: -0.01em;
  line-height: 1.35;
}
.chapter-meta { display: block; font-size: 13px; color: var(--text-2); line-height: 1.35; }

.chapter-ring { position: relative; width: 42px; height: 42px; flex: none; }
.chapter-ring svg { width: 42px; height: 42px; transform: rotate(-90deg); }
.chapter-ring .cr-bg { fill: none; stroke: var(--line-strong); stroke-width: 5; }
.chapter-ring .cr-fg {
  fill: none; stroke: var(--accent); stroke-width: 5; stroke-linecap: round;
  transition: stroke-dashoffset 0.5s ease;
}
.chapter-ring .cr-text {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 11px; font-weight: 600; color: var(--text-2);
  white-space: nowrap; letter-spacing: -0.02em;
}
.chapter-ring.is-empty .cr-text { font-size: 10px; color: var(--text-3); letter-spacing: -0.04em; }

.chev { flex: none; width: 16px; height: 16px; color: var(--text-3); }

.foot {
  margin: 34px 0 0;
  text-align: center;
  font-size: 12px;
  color: var(--text-3);
}

/* --------------------------------------------------------------- 顶部导航条 */
.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 6px 0 16px;
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
}
@supports not (backdrop-filter: blur(20px)) {
  .topbar { background: var(--bg); }
}

.icon-btn {
  width: 36px; height: 36px; flex: none;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  color: var(--accent);
  background: var(--card);
  border: 1px solid var(--line);
  transition: background 0.18s, transform 0.18s;
}
.icon-btn:hover { background: var(--accent-soft); }
.icon-btn:active { transform: scale(0.94); }
.icon-btn svg { width: 19px; height: 19px; }

.topbar-mid { flex: 1; min-width: 0; }
.topbar-title {
  font-size: 15px; font-weight: 600; letter-spacing: -0.01em;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.topbar-sub { font-size: 12px; color: var(--text-2); margin-top: 1px; }
.topbar-right {
  flex: none;
  padding: 3px 10px;
  font-size: 13px;
  color: var(--text-2);
  font-variant-numeric: tabular-nums;
  border-radius: 980px;
  background-color: transparent;
  transform-origin: right center;
}

/* 答对瞬间：右上角比分胶囊整体闪一次绿。
   用「整块变色 + 放大 + 光晕」而不是只改文字颜色——只在文字上做变化太小太快，
   视线在题目上时几乎看不到。纯视觉，不阻塞跳题。 */
.topbar-right.pulse { animation: score-pulse 0.65s cubic-bezier(0.2, 0.8, 0.2, 1); }

@keyframes score-pulse {
  0% {
    color: #fff;
    background-color: var(--green);
    transform: scale(1.3);
    box-shadow: 0 2px 12px rgba(52, 199, 89, 0.5);
  }
  50% {
    color: #fff;
    background-color: var(--green);
    transform: scale(1.14);
    box-shadow: 0 2px 10px rgba(52, 199, 89, 0.34);
  }
  75% {
    color: var(--green);
    background-color: var(--green-soft);
    transform: scale(1.02);
    box-shadow: 0 2px 6px rgba(52, 199, 89, 0);
  }
  100% {
    color: var(--text-2);
    background-color: transparent;
    transform: scale(1);
    box-shadow: 0 2px 6px rgba(52, 199, 89, 0);
  }
}

/* 关闭动效偏好下的降级：去掉缩放与光晕，只保留变色（属于信息反馈，不是装饰动效） */
@keyframes score-pulse-flat {
  0%, 55% { color: #fff; background-color: var(--green); }
  100% { color: var(--text-2); background-color: transparent; }
}

/* 顶栏右侧的主操作按钮（错题集「开始刷题」）：描边胶囊，
   原先只有裸文字，看着不像按钮也容易被忽略 */
.topbar-btn {
  flex: none;
  padding: 7px 16px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--accent);
  background: var(--card);
  border: 1px solid var(--accent);
  border-radius: 980px;
  white-space: nowrap;
  transition: background 0.18s, color 0.18s, border-color 0.18s, transform 0.18s;
}
.topbar-btn:not(:disabled):hover { background: var(--accent); color: #fff; }
.topbar-btn:not(:disabled):active { transform: scale(0.97); }
.topbar-btn:disabled {
  color: var(--text-3);
  border-color: var(--line-strong);
  background: var(--card);
  opacity: 0.6;
  cursor: not-allowed;
}

/* --------------------------------------------------------------- 工具按钮行 */
.tool-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}

.chip-btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 14px;
  font-size: 13px; font-weight: 500;
  color: var(--text-2);
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 980px;
  transition: background 0.18s, color 0.18s, transform 0.18s;
}
.chip-btn svg { width: 15px; height: 15px; }
.chip-btn:hover { background: var(--accent-soft); color: var(--accent); }
.chip-btn:active { transform: scale(0.97); }
.chip-danger:not(:disabled):hover { background: var(--red-soft); color: var(--red); }
.chip-btn:disabled { opacity: 0.45; cursor: not-allowed; }

/* ------------------------------------------------------------------ 进度条 */
.progress {
  height: 4px;
  border-radius: 980px;
  background: var(--line);
  overflow: hidden;
  margin-bottom: 24px;
}
.progress-bar {
  height: 100%;
  width: 0;
  border-radius: 980px;
  background: var(--accent);
  transition: width 0.35s cubic-bezier(0.2, 0.8, 0.2, 1);
}

/* -------------------------------------------------------------------- 题目 */
.quiz-body { padding-bottom: 12px; }

.q-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
  padding: 26px 24px 24px;
  margin-bottom: 20px;
}

.q-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-3);
  letter-spacing: 0.02em;
  margin-bottom: 12px;
}

.q-stem {
  margin: 0;
  font-size: 19px;
  line-height: 1.62;
  font-weight: 500;
  letter-spacing: -0.01em;
  word-break: break-word;
}

.options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 16px;
}

.opt {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 62px;
  padding: 12px 16px;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text);
  background: var(--card);
  border: 1.5px solid var(--line-strong);
  border-radius: var(--radius-md);
  transition: transform 0.18s cubic-bezier(0.2, 0.8, 0.2, 1), border-color 0.18s,
    background 0.18s, color 0.18s;
}
.opt:not([disabled]):hover { border-color: var(--accent); color: var(--accent); }
.opt:not([disabled]):active { transform: scale(0.975); }
.opt[disabled] { cursor: default; }

.opt-dot {
  width: 20px; height: 20px; flex: none;
  border: 1.5px solid currentColor;
  border-radius: 50%;
  position: relative;
  opacity: 0.36;
  transition: opacity 0.18s;
}
.opt-dot::after {
  content: "";
  position: absolute; inset: 3.5px;
  border-radius: 50%;
  background: currentColor;
  transform: scale(0);
  transition: transform 0.2s cubic-bezier(0.2, 0.8, 0.2, 1);
}
.opt.is-picked .opt-dot { opacity: 1; }
.opt.is-picked .opt-dot::after { transform: scale(1); }

.opt.is-correct {
  color: var(--green);
  border-color: var(--green);
  background: var(--green-soft);
}
.opt.is-wrong {
  color: var(--red);
  border-color: var(--red);
  background: var(--red-soft);
}

/* -------------------------------------------------------------------- 反馈 */
.feedback {
  border-radius: var(--radius-md);
  padding: 16px 18px;
  margin-bottom: 18px;
  border: 1px solid transparent;
  animation: fade-in 0.24s ease both;
}
.feedback.is-correct { background: var(--green-soft); border-color: rgba(52, 199, 89, 0.28); }
.feedback.is-wrong { background: var(--red-soft); border-color: rgba(255, 59, 48, 0.28); }

.fb-head {
  display: flex; align-items: center; gap: 8px;
  font-size: 15px; font-weight: 600;
  margin-bottom: 2px;
}
.feedback.is-correct .fb-head { color: var(--green); }
.feedback.is-wrong .fb-head { color: var(--red); }
.fb-head svg { width: 18px; height: 18px; flex: none; }

.fb-meta {
  font-size: 14px; color: var(--text-2);
  margin-top: 6px;
}
.fb-meta b { color: var(--text); font-weight: 600; }

.fb-expl {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
}
.fb-expl-label {
  font-size: 12px; font-weight: 600; letter-spacing: 0.06em;
  color: var(--text-3); text-transform: uppercase;
  margin-bottom: 6px;
}
.fb-expl-text {
  font-size: 15px; line-height: 1.7; color: var(--text);
  white-space: pre-wrap; word-break: break-word;
}
.fb-expl-text.is-empty { color: var(--text-3); font-style: normal; }

/* ------------------------------------------------------------------ 底部导航 */
.quiz-nav { display: flex; gap: 12px; }

.btn {
  flex: 1;
  min-height: 50px;
  padding: 12px 20px;
  border-radius: 980px;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: transform 0.18s cubic-bezier(0.2, 0.8, 0.2, 1), background 0.18s,
    opacity 0.18s, color 0.18s;
}
.btn:not(:disabled):active { transform: scale(0.975); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }

.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:not(:disabled):hover { filter: brightness(1.06); }

.btn-ghost {
  background: var(--card);
  color: var(--text);
  border: 1px solid var(--line-strong);
}
.btn-ghost:not(:disabled):hover { background: var(--accent-soft); color: var(--accent); border-color: transparent; }

.btn-soft { background: var(--accent-soft); color: var(--accent); }
.btn-soft:not(:disabled):hover { filter: brightness(1.04); }

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

/* -------------------------------------------------------------------- 结果 */
.result-wrap { padding: 12px 0; text-align: center; }

.result-ring {
  position: relative;
  width: 176px; height: 176px;
  margin: 18px auto 22px;
}
.result-ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.ring-bg { fill: none; stroke: var(--line); stroke-width: 8; }
.ring-fg {
  fill: none;
  stroke: var(--accent);
  stroke-width: 8;
  stroke-linecap: round;
  stroke-dasharray: 326.7;
  stroke-dashoffset: 326.7;
  transition: stroke-dashoffset 0.9s cubic-bezier(0.2, 0.8, 0.2, 1), stroke 0.3s;
}
.ring-center {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
}
.ring-rate {
  font-size: 42px; font-weight: 700; letter-spacing: -0.03em;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}
.ring-label { font-size: 12px; color: var(--text-3); margin-top: 6px; letter-spacing: 0.08em; }

.result-count { font-size: 17px; font-weight: 600; margin: 0; }
.result-hint { font-size: 14px; color: var(--text-2); margin: 8px 0 0; }

.result-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 26px 0 8px;
}
.result-actions .btn { flex: none; width: 100%; }

.result-review { margin-top: 30px; text-align: left; }

.review-title {
  font-size: 13px; font-weight: 600; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--text-3);
  margin: 0 0 10px; padding-left: 2px;
}

/* ---------------------------------------------------------------- 错题列表 */
.wrong-list { display: flex; flex-direction: column; gap: 12px; }

.wrong-item {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-1);
  padding: 16px 18px 14px;
  animation: fade-in 0.24s ease both;
}

.wrong-top {
  display: flex; align-items: center; gap: 10px;
  margin-bottom: 10px;
}
.wrong-tag {
  font-size: 11px; font-weight: 600;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 3px 9px;
  border-radius: 980px;
  white-space: nowrap;
  max-width: 60%;
  overflow: hidden; text-overflow: ellipsis;
}
.wrong-spacer { flex: 1; }

.remove-btn {
  font-size: 13px; font-weight: 500;
  color: var(--text-3);
  padding: 4px 10px;
  border-radius: 980px;
  border: 1px solid var(--line);
  transition: background 0.18s, color 0.18s;
  white-space: nowrap;
}
.remove-btn:hover { background: var(--red-soft); color: var(--red); border-color: transparent; }

.wrong-stem {
  margin: 0 0 10px;
  font-size: 16px; line-height: 1.6; font-weight: 500;
  word-break: break-word;
}

.wrong-answer {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 14px; font-weight: 600;
  padding: 3px 10px;
  border-radius: 980px;
  margin-bottom: 10px;
}
.wrong-answer.is-true { color: var(--green); background: var(--green-soft); }
.wrong-answer.is-false { color: var(--red); background: var(--red-soft); }

.wrong-expl {
  font-size: 14px; line-height: 1.7; color: var(--text-2);
  padding-top: 10px;
  border-top: 1px solid var(--line);
  white-space: pre-wrap; word-break: break-word;
}

.empty-state {
  text-align: center;
  padding: 64px 20px;
  color: var(--text-3);
}
.empty-state svg { width: 44px; height: 44px; margin: 0 auto 14px; opacity: 0.4; }
.empty-title { font-size: 16px; font-weight: 600; color: var(--text-2); margin: 0 0 6px; }
.empty-desc { font-size: 14px; margin: 0; line-height: 1.6; }

/* -------------------------------------------------------------------- 弹窗 */
.modal { position: fixed; inset: 0; z-index: 100; display: flex; align-items: center; justify-content: center; }
.modal[hidden] { display: none; }

.modal-mask {
  position: absolute; inset: 0;
  background: rgba(0, 0, 0, 0.32);
  backdrop-filter: blur(3px);
  -webkit-backdrop-filter: blur(3px);
  animation: fade-in 0.2s ease both;
}

.modal-card {
  position: relative;
  width: min(340px, calc(100vw - 44px));
  background: var(--bg-elevated);
  border-radius: 22px;
  padding: 24px 20px 16px;
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.24);
  animation: modal-in 0.32s cubic-bezier(0.2, 0.9, 0.2, 1) both;
  text-align: center;
}
@keyframes modal-in {
  from { opacity: 0; transform: translateY(14px) scale(0.96); }
  to { opacity: 1; transform: none; }
}

.modal-head h3 { margin: 0; font-size: 19px; font-weight: 600; letter-spacing: -0.01em; }
.modal-head p { margin: 6px 0 0; font-size: 13px; color: var(--text-2); }

.modal-options { display: flex; flex-direction: column; gap: 8px; margin: 20px 0 14px; }

.modal-opt {
  display: flex; align-items: baseline; justify-content: space-between; gap: 10px;
  padding: 14px 16px;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  text-align: left;
  transition: background 0.18s, border-color 0.18s, transform 0.18s;
}
.modal-opt span { font-size: 16px; font-weight: 600; }
.modal-opt em { font-size: 12px; font-style: normal; color: var(--text-3); }
.modal-opt:hover { background: var(--accent-soft); border-color: transparent; }
.modal-opt:hover span { color: var(--accent); }
.modal-opt:active { transform: scale(0.985); }

.modal-cancel {
  width: 100%;
  padding: 13px;
  font-size: 16px; font-weight: 500;
  color: var(--text-2);
  border-radius: var(--radius-md);
  transition: background 0.18s;
}
.modal-cancel:hover { background: var(--line); }

/* -------------------------------------------------------------------- 提示 */
.toast {
  position: fixed;
  left: 50%;
  bottom: 40px;
  transform: translateX(-50%);
  max-width: calc(100vw - 48px);
  padding: 11px 20px;
  border-radius: 980px;
  background: rgba(28, 28, 30, 0.92);
  color: #fff;
  font-size: 14px;
  font-weight: 500;
  z-index: 200;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.22);
  animation: toast-in 0.28s cubic-bezier(0.2, 0.9, 0.2, 1) both;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.toast[hidden] { display: none; }
@keyframes toast-in {
  from { opacity: 0; transform: translate(-50%, 12px); }
  to { opacity: 1; transform: translate(-50%, 0); }
}

/* ------------------------------------------------------------------ 响应式 */
@media (max-width: 560px) {
  .app { padding: 26px 16px 56px; }
  .hero-title { font-size: 26px; }
  .hero-sub { font-size: 13px; }
  /* 窄屏：切换器独占第一行、右对齐，标题与副标题落到第二行。
     右对齐同时保证下拉菜单（right:0 相对切换器）向左展开时不越出屏幕左边界。
     PC 端（>560px）不受影响，标题与切换器仍在同一行。 */
  .hero-top { flex-wrap: wrap; gap: 12px; }
  .bank-switch { order: 1; margin-left: auto; gap: 6px; }
  .hero-heading { order: 2; flex: 1 1 100%; }
  .bank-switch-hint { font-size: 12px; }
  .bank-btn { padding: 7px 10px 7px 12px; font-size: 13px; }
  .bank-btn-label { max-width: 72px; }
  .bank-menu { width: calc(100vw - 32px); }
  .quick-card { padding: 15px 15px 14px; }
  .quick-title { font-size: 16px; }
  .quick-desc { font-size: 12px; }
  .q-card { padding: 22px 18px 20px; border-radius: 16px; }
  .q-stem { font-size: 17px; line-height: 1.62; }
  .opt { min-height: 58px; font-size: 16px; }
  .ring-rate { font-size: 36px; }
  .result-ring { width: 152px; height: 152px; }
  .topbar { padding-top: 2px; }

  /* 刷题页：整屏纵向 flex，把四个按钮（正确/错误、上一题/下一题）沉到页面最下面。
     手机屏幕高、题目短时它们原本浮在中间，下方留一大片空白。
     解析用 order 排到选项之前，答错时紧贴题目；DOM 顺序不变。
     同时收紧 .app 底部内边距，让按钮贴近屏幕底；底部留白 64px
     （min-height 里扣的是 .app 上下内边距之和 26 + 64 = 90，改底部留白要同步改这里）。
     内容比一屏还高时，auto 外边距失效，按钮自然跟随内容末尾、可滚动。 */
  body.is-quiz .app { padding-bottom: 64px; }
  #view-quiz.is-active {
    display: flex;
    flex-direction: column;
    min-height: calc(100vh - 90px);
    min-height: calc(100dvh - 90px);
  }
  #view-quiz .quiz-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding-bottom: 0;                 /* 底部间距交给 .app 统一控制 */
  }
  #view-quiz .q-card { order: 1; }
  #view-quiz .feedback { order: 2; }
  #view-quiz .options { order: 3; margin-top: auto; }
  #view-quiz .quiz-nav { order: 4; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  /* 「答对了」的绿色确认保留：只去掉缩放/光晕这类位移动效，颜色反馈照旧 */
  .topbar-right.pulse { animation: score-pulse-flat 0.7s linear !important; }
}