:root {
  --bg: #f6f8fb;
  --card: #ffffff;
  --border: #e6e9ef;
  --text: #1f2937;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-soft: #eff4ff;
  --ok: #16a34a;
  --ok-soft: #f0fdf4;
  --bad: #dc2626;
  --bad-soft: #fef2f2;
  --warn: #b45309;
  --shadow: 0 1px 3px rgba(16,24,40,.06), 0 8px 24px rgba(16,24,40,.05);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  -webkit-text-size-adjust: 100%;
}

/* 顶部栏 */
.topbar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 24px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}
.topbar h1 { font-size: 18px; margin: 0; font-weight: 600; }
.back { color: var(--muted); text-decoration: none; font-size: 14px; white-space: nowrap; }
.back:hover { color: var(--accent); }

/* 布局：左（时钟，讲解也在里面） / 右（作答） / 底部整行（选项） */
.layout {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px 24px 64px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 350px;
  gap: 24px;
  align-items: start;
}
.clock-pane { min-width: 0; }
.panel { align-self: stretch; }
.panel .card { position: sticky; top: 20px; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 22px 24px 24px;
  box-shadow: var(--shadow);
}
.card h2 { margin: 0 0 6px; font-size: 16px; }

.hint { color: var(--muted); font-size: 12.5px; margin: 0 0 16px; }

/* 读数提示条 */
.badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  min-height: 68px;              /* 固定高度：读数条出现时时钟不会上下跳 */
  justify-content: center;
  padding: 8px 18px;
  margin-bottom: 12px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: linear-gradient(180deg, #fbfcff, #f4f7ff);
  transition: opacity .2s ease, border-color .2s ease;
}
.badge.empty { opacity: 0; border-color: transparent; }
.badge-main { font-size: 24px; font-weight: 700; color: var(--accent); line-height: 1.2; }
.badge-sub { font-size: 13px; color: var(--muted); }

/* 时钟 */
.clock-stage { display: flex; justify-content: center; }
#clock {
  width: 100%;
  max-width: 466px;
  height: auto;
  display: block;
  user-select: none;
}

.face { fill: #ffffff; stroke: var(--border); stroke-width: 2; }
.face-inner { fill: none; stroke: #eef2f7; stroke-width: 1.5; }

.tick { stroke-linecap: round; }
.tick-major { stroke: #64748b; stroke-width: 5; }
.tick-minor { stroke: #cbd5e1; stroke-width: 2.5; }

.hour-num {
  font-size: 34px;
  font-weight: 600;
  fill: #1f2937;
  font-family: inherit;
  transition: fill .25s ease;
}
.min-num {
  font-size: 15px;
  font-weight: 500;
  fill: #94a3b8;
  font-family: inherit;
}
.hour-num.live { fill: #f97316; }
.min-num.live { fill: #f97316; }

.sweep { fill: rgba(37,99,235,.12); }

.rim-dot { fill: var(--accent); stroke: #fff; stroke-width: 2.5; }

/* 时针所在的「两格之间」高亮带（衬在数字下面，不压字） */
.hour-guide {
  fill: none;
  stroke: rgba(249,115,22,.22);
  stroke-width: 34;
  stroke-linecap: round;
  transition: opacity .3s ease;
}

.hand rect { fill: #1f2937; transition: fill .25s ease; }
.hand { transition: opacity .25s ease; }
.minute-hand rect { fill: #2563eb; }
.hand.active rect { fill: #f97316; filter: drop-shadow(0 0 7px rgba(249,115,22,.65)); }

#clock.focus-minute .hour-hand { opacity: .18; }
#clock.focus-minute .hour-num { fill: #cbd5e1; }
#clock.focus-hour .minute-hand { opacity: .18; }
#clock.focus-hour .sweep, #clock.focus-hour .rim-dot { opacity: .2; }

.pin { fill: #1f2937; }
.pin-dot { fill: #ffffff; }

/* 按钮 */
.btn {
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  padding: 8px 14px;
  border-radius: 9px;
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  transition: background .15s, border-color .15s, transform .05s;
}
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff; padding: 10px 20px; }
.btn-primary:hover { background: #1d4ed8; border-color: #1d4ed8; }
.btn-primary:disabled { background: #93b4f7; border-color: #93b4f7; }
.btn-outline { color: var(--accent); border-color: #c7d9fb; background: var(--accent-soft); font-weight: 600; }
.btn-outline:hover { background: #e3edff; border-color: var(--accent); }
.btn-block { width: 100%; margin-top: 6px; padding: 11px; }

/* 钟表下方：出题 + 讲解入口，同一行居中 */
.clock-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-top: 18px;
}
.explain-launch { display: flex; justify-content: center; margin: 0; }

.btn-explain {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 10px 24px;
  border-radius: 999px;
  font-size: 14.5px;
  font-weight: 600;
  color: #b45309;
  background: #fff7ed;
  border: 1px solid #fed7aa;
}
.btn-explain:hover { background: #ffedd5; border-color: #f97316; color: #9a3412; }
.btn-explain:disabled { opacity: .6; }
.explain-ico { font-size: 11px; line-height: 1; }

/* 讲解：就地在时钟下方展开，不单独占板块 */
.explain {
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px dashed var(--border);
}
.exp-steps { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.step {
  font-size: 12.5px;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 4px 12px;
  background: #fbfcfe;
  transition: all .25s ease;
}
.step.on { color: #fff; background: var(--accent); border-color: var(--accent); font-weight: 600; }
.step.done { color: var(--ok); border-color: #bbf7d0; background: var(--ok-soft); }

.exp-text {
  font-size: 15px;
  line-height: 1.9;
  color: var(--text);
  min-height: 76px;
  border-radius: 12px;
  padding: 14px 16px;
  background: #fbfcfe;
  border: 1px solid var(--border);
}
.exp-text:empty { display: none; }
.exp-text.fade { animation: fadeUp .32s ease-out; }
.exp-text em { font-style: normal; color: var(--accent); font-weight: 600; }
.exp-text strong { color: #b45309; }
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(5px); }
  to { opacity: 1; transform: none; }
}

/* 作答：时 / 分并排同一行，两个面板都按整行宽度展开 */
.answer-body { position: relative; display: flex; gap: 10px; margin-bottom: 12px; }
.ctrl-row { flex: 1 1 0; min-width: 0; position: relative; }

.digit {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 6px 12px;
  background: #f7f9ff;
  border: 1px solid #dbe5fb;
  border-radius: 14px;
  font-family: inherit;
  cursor: pointer;
  box-shadow: inset 0 1px 2px rgba(37,99,235,.06);
  transition: border-color .15s, background .15s, box-shadow .15s;
}
.digit:hover { border-color: var(--accent); background: #f2f6ff; }
.digit[aria-expanded="true"] { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(37,99,235,.13); }
.digit:disabled { opacity: .5; cursor: not-allowed; }
.digit-label { flex-shrink: 0; font-size: 12.5px; color: var(--muted); }
.digit-val {
  flex: 1;
  text-align: center;
  font-size: 34px;
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: 1px;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum";
}
.digit-caret { flex-shrink: 0; font-size: 11px; color: #9aa3b2; transition: transform .2s ease; }
.digit[aria-expanded="true"] .digit-caret { transform: rotate(180deg); }
/* 分钟只选了十位、个位还没选时，个位位置显示一个闪动的「?」 */
.digit-val .pick-ph {
  color: #b6c1d6;
  animation: phPulse 1.15s ease-in-out infinite;
}
@keyframes phPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: .28; }
}

/* 弹出的数字面板 */
.picker {
  position: absolute;
  left: 0;
  right: 0;
  top: calc(100% + 8px);
  z-index: 40;
  padding: 12px;
  background: #fff;
  border: 1px solid #dbe5fb;
  border-radius: 14px;
  box-shadow: 0 12px 32px rgba(16,24,40,.16);
  overflow-y: auto;
  animation: popIn .14s ease-out;
}
@keyframes popIn {
  from { opacity: 0; transform: translateY(-5px); }
  to { opacity: 1; transform: none; }
}
/* 下方放不下时向上翻 */
.picker.up { top: auto; bottom: calc(100% + 8px); animation: popInUp .14s ease-out; }
@keyframes popInUp {
  from { opacity: 0; transform: translateY(5px); }
  to { opacity: 1; transform: none; }
}
/* 面板整体不高，窗口很矮时仍给个兜底 */
#pickerM { max-height: 78vh; overflow-y: auto; }
.picker-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 10px;
  padding-left: 2px;
  font-size: 12.5px;
  color: var(--muted);
}
.picker-x {
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: 18px;
  line-height: 1;
  padding: 0 4px;
  cursor: pointer;
  font-family: inherit;
}
.picker-x:hover { color: var(--accent); }

.picker-grid { display: grid; gap: 5px; }
.g-hour { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* 分钟：左组十位 0–5、右组个位 0–9，各自排成多排多列的小键盘（和小时面板一样） */
.digit-cols { display: flex; align-items: stretch; gap: 14px; }
.digit-col {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 8px 8px 9px;
  background: #fafbfe;
  border: 1px solid #eef2f7;
  border-radius: 12px;
}
.c-tens { flex: 3; }
.c-units { flex: 5; }
.col-label { font-size: 12px; color: var(--muted); text-align: center; }
.g-tens { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.g-units { grid-template-columns: repeat(5, minmax(0, 1fr)); }

/* 个位还没选就想提交：把「个位」这一栏抖一下并变暖色 */
.digit-col.urge {
  border-color: #fb923c;
  background: #fff7ed;
  animation: urgeShake .5s ease;
}
.digit-col.urge .col-label { color: #c2410c; font-weight: 600; }
@keyframes urgeShake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-4px); }
  40% { transform: translateX(4px); }
  60% { transform: translateX(-3px); }
  80% { transform: translateX(2px); }
}

.picker-grid button {
  height: 42px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #fff;
  color: var(--text);
  font-size: 16px;
  font-family: inherit;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  overflow: hidden;
  cursor: pointer;
  transition: background .12s, border-color .12s, color .12s;
}
.g-digit button { height: 38px; font-size: 16px; }
.picker-grid button:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.picker-grid button.sel { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }

.feedback { font-size: 14px; line-height: 1.7; margin-top: 14px; }
.feedback:empty { display: none; }
.feedback b { color: var(--accent); }
.feedback.ok {
  color: #15803d;
  background: var(--ok-soft);
  border: 1px solid #bbf7d0;
  border-radius: 12px;
  padding: 12px 14px;
}
.feedback.ok b { color: #15803d; }
.feedback.bad {
  color: #b91c1c;
  background: var(--bad-soft);
  border: 1px solid #fecaca;
  border-radius: 12px;
  padding: 12px 14px;
}
.feedback.bad b { color: #b91c1c; }

.score { margin-top: 14px; font-size: 12.5px; color: var(--muted); text-align: center; }

/* 底部选项条（整行，自动保存） */
.options-card {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  gap: 16px 40px;
  align-items: center;
  padding: 18px 24px;
  background: #fbfcff;
}
.options-group { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
.opts-title { font-size: 12.5px; color: var(--muted); letter-spacing: 1px; }
.opts-saved { font-size: 12px; color: #9aa3b2; }

.check { display: flex; align-items: center; gap: 7px; color: var(--text); font-size: 14px; cursor: pointer; }
.check input { accent-color: var(--accent); width: 16px; height: 16px; }
.mini { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--muted); }
.mini select {
  padding: 7px 10px;
  border: 1px solid var(--border);
  border-radius: 9px;
  font-size: 13px;
  background: #fff;
  color: var(--text);
  font-family: inherit;
}

@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; padding: 20px 16px 56px; gap: 18px; }
  .clock-pane { order: -1; }
  .panel .card { position: static; }
  #clock { max-width: 350px; }
  .options-card { flex-direction: column; align-items: flex-start; gap: 14px; }

  /* 窄屏：出题与讲解按钮排在一行，缩紧内边距避免换行 */
  .clock-actions { gap: 10px; }
  .clock-actions .btn,
  .clock-actions .btn-explain { padding: 9px 14px; font-size: 13.5px; }

  /* 窄屏：输入框常在屏幕下方，改成贴着屏幕底部的浮层，保证整块都能看见 */
  .picker {
    position: fixed;
    left: 14px;
    right: 14px;
    top: auto;
    bottom: 14px;
    max-height: 70vh;
    overflow-y: auto;
    animation: popInSheet .16s ease-out;
  }
  .picker.up { top: auto; bottom: 14px; }
  .digit-cols { gap: 10px; }
  .digit-col { padding: 6px 6px 7px; gap: 5px; }
  .g-digit button { height: 34px; }
}
@keyframes popInSheet {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: none; }
}

/* 系统开启「减少动态效果」时，不再闪动 */
@media (prefers-reduced-motion: reduce) {
  .digit-val .pick-ph { animation: none; opacity: .75; }
}