/* ============ 小学数学提优乐园 · 低龄友好样式 ============ */
:root {
  --bg: #fff8ef;
  --ink: #3a3552;
  --ink-soft: #7a7494;
  --card: #ffffff;
  --line: #f0e6d8;
  --orange: #ff9f43;
  --orange-d: #e8871e;
  --green: #2ecc8f;
  --green-d: #23a973;
  --blue: #54a0ff;
  --blue-d: #2f80ed;
  --purple: #a55eea;
  --purple-d: #8b45d0;
  --red: #ff6b6b;
  --yellow: #ffd93d;
  --shadow: 0 6px 18px rgba(90, 70, 40, .10);
  --radius: 20px;
  --cat-color: var(--orange);
  --cat-color-d: var(--orange-d);
}

* { box-sizing: border-box; }
html { font-size: 17px; }
body {
  margin: 0;
  font-family: "Varela Round", "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  background:
    radial-gradient(circle at 8% 6%, #ffe9c9 0 140px, transparent 140px),
    radial-gradient(circle at 92% 12%, #d7f5e6 0 160px, transparent 160px),
    radial-gradient(circle at 85% 85%, #ddebff 0 180px, transparent 180px),
    var(--bg);
  color: var(--ink);
  line-height: 1.65;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ---------- 顶栏 ---------- */
.site-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 22px;
  background: rgba(255, 255, 255, .82);
  backdrop-filter: blur(6px);
  border-bottom: 3px dashed var(--line);
  position: sticky; top: 0; z-index: 50;
}
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); }
.logo-badge {
  font-size: 30px; width: 50px; height: 50px; display: grid; place-items: center;
  background: linear-gradient(135deg, #ffd93d, #ff9f43);
  border-radius: 16px; box-shadow: var(--shadow);
}
.logo-text { font-size: 21px; font-weight: 700; letter-spacing: 1px; }
.logo-text em { font-style: normal; color: var(--orange-d); }
.site-nav { display: flex; gap: 10px; }
.site-nav a {
  text-decoration: none; color: var(--ink); font-weight: 700;
  padding: 8px 16px; border-radius: 999px; background: #fff;
  border: 2px solid var(--line); transition: .15s;
}
.site-nav a:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.nav-pill { background: #fff6df !important; border-color: #ffe3a3 !important; }

main { flex: 1; width: min(1060px, 100% - 32px); margin: 0 auto; padding: 26px 0 50px; }

.site-footer { text-align: center; padding: 18px; color: var(--ink-soft); border-top: 3px dashed var(--line); }

/* ---------- 通用组件 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px; justify-content: center;
  font: inherit; font-weight: 800; cursor: pointer;
  border: none; border-radius: 999px; padding: 12px 26px;
  color: #fff; background: var(--blue); box-shadow: 0 4px 0 rgba(0,0,0,.12);
  transition: .12s; text-decoration: none;
}
.btn:active { transform: translateY(3px); box-shadow: none; }
.btn:hover { filter: brightness(1.06); }
.btn-orange { background: var(--orange); }
.btn-green { background: var(--green); }
.btn-blue { background: var(--blue); }
.btn-purple { background: var(--purple); }
.btn-ghost {
  background: #fff; color: var(--ink); border: 2px solid var(--line);
  box-shadow: none;
}
.btn-sm { padding: 8px 16px; font-size: 15px; }
.btn-lg { padding: 15px 34px; font-size: 19px; }
.btn[disabled] { opacity: .5; cursor: not-allowed; }

.chip {
  display: inline-block; padding: 3px 12px; border-radius: 999px;
  font-size: 13.5px; font-weight: 700;
}
.chip-grade { background: #eaf3ff; color: var(--blue-d); }
.chip-tag { background: #f3ecff; color: var(--purple-d); }
.chip-star { background: #fff3d6; color: #b07d10; letter-spacing: 1px; }
.chip-done { background: #e2f8ee; color: var(--green-d); }
.chip-adv { background: #ffe9e9; color: #d63d3d; }

.card {
  background: var(--card); border-radius: var(--radius);
  box-shadow: var(--shadow); border: 2px solid var(--line);
}

.empty-tip { text-align: center; color: var(--ink-soft); padding: 60px 0; font-size: 17px; }

/* ---------- 首页 ---------- */
.hero { text-align: center; padding: 26px 10px 34px; }
.hero h1 { font-size: 34px; margin: 0 0 10px; letter-spacing: 2px; }
.hero h1 .wiggle { display: inline-block; animation: wiggle 2.2s ease-in-out infinite; }
@keyframes wiggle { 0%,100%{transform:rotate(-6deg)} 50%{transform:rotate(8deg)} }
.hero p { color: var(--ink-soft); font-size: 17px; margin: 0; }

.cat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 20px; }
.cat-card {
  padding: 26px 22px; text-align: center; text-decoration: none; color: var(--ink);
  border-top: 8px solid var(--c); position: relative; overflow: hidden;
  transition: .16s; display: block;
}
.cat-card:hover { transform: translateY(-6px) scale(1.02); box-shadow: 0 14px 26px rgba(90,70,40,.16); }
.cat-card .cat-emoji { font-size: 52px; display: block; margin-bottom: 8px; }
.cat-card h2 { margin: 0 0 6px; font-size: 22px; color: var(--cd); }
.cat-card p { margin: 0; font-size: 14.5px; color: var(--ink-soft); min-height: 2.9em; }
.cat-card .cat-count {
  position: absolute; top: 14px; right: 14px;
  background: var(--c); color: #fff; font-weight: 800;
  border-radius: 999px; padding: 3px 12px; font-size: 13px;
}
.home-section-title { font-size: 21px; margin: 38px 0 14px; display: flex; align-items: center; gap: 8px; }

.howto { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; }
.howto .step { padding: 18px; text-align: center; }
.howto .step b { font-size: 30px; display: block; margin-bottom: 6px; }
.howto .step span { font-size: 14.5px; color: var(--ink-soft); }

/* ---------- 分类列表页 ---------- */
.cat-banner {
  display: flex; align-items: center; gap: 16px; padding: 20px 24px;
  border-left: 10px solid var(--cat-color); margin-bottom: 18px; flex-wrap: wrap;
}
.cat-banner .cat-emoji { font-size: 44px; }
.cat-banner h1 { margin: 0; font-size: 26px; }
.cat-banner .cat-sub { color: var(--ink-soft); font-size: 14.5px; }
.cat-banner .banner-actions { margin-left: auto; display: flex; gap: 10px; flex-wrap: wrap; }

.filters {
  display: flex; flex-wrap: wrap; gap: 10px; align-items: center;
  padding: 14px 18px; margin-bottom: 18px;
}
.filters .f-label { font-weight: 800; font-size: 14.5px; color: var(--ink-soft); }
.f-btn {
  font: inherit; font-size: 14.5px; font-weight: 700; cursor: pointer;
  border: 2px solid var(--line); background: #fff; color: var(--ink-soft);
  border-radius: 999px; padding: 5px 15px; transition: .12s;
}
.f-btn:hover { border-color: var(--cat-color); color: var(--ink); }
.f-btn.on { background: var(--cat-color); border-color: var(--cat-color); color: #fff; }
.filters input[type=search] {
  font: inherit; padding: 7px 16px; border-radius: 999px;
  border: 2px solid var(--line); outline: none; min-width: 170px; margin-left: auto;
}
.filters input[type=search]:focus { border-color: var(--cat-color); }
.sub-row {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  width: 100%; border-top: 2px dashed var(--line); padding-top: 10px; margin-top: 2px;
}
.sub-row .f-btn { font-size: 13.5px; padding: 3px 12px; }
.chip-sub { background: #e8f3ff; color: #2b6cb0; }

.plist { display: grid; gap: 14px; }
.p-item {
  display: flex; gap: 16px; align-items: flex-start;
  padding: 16px 20px; cursor: pointer; text-decoration: none; color: var(--ink);
  transition: .14s; border-left: 6px solid transparent;
}
.p-item:hover { border-left-color: var(--cat-color); transform: translateX(4px); }
.p-num {
  flex: none; width: 54px; height: 54px; border-radius: 16px;
  background: linear-gradient(135deg, var(--cat-color), var(--cat-color-d));
  color: #fff; display: grid; place-items: center; font-weight: 900; font-size: 15px;
}
.p-item.done .p-num { background: linear-gradient(135deg, var(--green), var(--green-d)); }
.p-main { flex: 1; min-width: 0; }
.p-q {
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  overflow: hidden; font-size: 15.5px;
}
.p-chips { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 8px; }
.p-status { flex: none; font-size: 24px; align-self: center; }

.pager { display: flex; justify-content: center; align-items: center; gap: 8px; margin-top: 22px; flex-wrap: wrap; }
.pager button {
  font: inherit; font-weight: 700; min-width: 42px; padding: 8px 12px;
  border-radius: 12px; border: 2px solid var(--line); background: #fff; cursor: pointer;
}
.pager button.on { background: var(--cat-color); border-color: var(--cat-color); color: #fff; }
.pager button:disabled { opacity: .4; cursor: default; }

/* ---------- 答题详情页 ---------- */
.pd-top { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; flex-wrap: wrap; }
.pd-top .grow { flex: 1; }
.pd-progress { font-size: 14px; color: var(--ink-soft); font-weight: 700; }

.pd-main { padding: 26px clamp(18px, 4vw, 40px) 30px; border-top: 10px solid var(--cat-color); }
.pd-chips { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.pd-question { font-size: 18.5px; line-height: 1.9; margin-bottom: 18px; white-space: pre-line; }
.pd-question .q-id { color: var(--ink-soft); font-size: 14px; font-weight: 800; display: block; margin-bottom: 6px; }

.pd-figure {
  margin: 0 auto 20px; max-width: 560px; text-align: center;
  background: #fffdf7; border: 2px dashed var(--line); border-radius: 16px; padding: 12px;
}
.pd-figure svg { max-width: 100%; height: auto; }

.answer-box { display: flex; gap: 12px; flex-wrap: wrap; align-items: stretch; margin: 22px 0 6px; }
.answer-go { width: 100%; margin: 22px 0 6px; }
.answer-box label { display: block; font-weight: 800; font-size: 15px; margin-bottom: 6px; color: var(--ink-soft); }
.answer-box .field { flex: 1; min-width: 220px; }
.answer-box input {
  width: 100%; font: inherit; font-size: 19px; font-weight: 700;
  padding: 12px 18px; border-radius: 16px; border: 3px solid var(--line); outline: none;
  background: #fffdf7;
}
.answer-box input:focus { border-color: var(--cat-color); }
.answer-box input.right { border-color: var(--green); background: #f0fbf6; }
.answer-box input.wrong { border-color: var(--red); background: #fff5f5; animation: shake .3s; }
@keyframes shake { 25%{transform:translateX(-6px)} 75%{transform:translateX(6px)} }

.feedback { font-weight: 800; margin: 10px 2px 0; min-height: 1.6em; }
.feedback.ok { color: var(--green-d); }
.feedback.no { color: var(--red); }

.action-row { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 20px; }

.panel { margin-top: 18px; padding: 18px 22px; border-radius: 18px; animation: pop .25s; }
@keyframes pop { from { transform: scale(.96); opacity: 0 } to { transform: scale(1); opacity: 1 } }
.panel h3 { margin: 0 0 10px; font-size: 17px; display: flex; align-items: center; gap: 8px; }
.panel-hint { background: #fff6df; border: 2px solid #ffe3a3; }
.panel-hint p { margin: 6px 0; }
.knowledge-line { font-size: 16px; }
.knowledge-line b { color: var(--orange-d); }

.panel-solution { background: #eef7ff; border: 2px solid #cfe6ff; }
.solution-steps { counter-reset: step; margin: 0; padding: 0; list-style: none; }
.solution-steps li {
  counter-increment: step; position: relative; padding: 10px 12px 10px 52px;
  background: #fff; border-radius: 14px; margin-bottom: 10px;
  box-shadow: 0 2px 6px rgba(60,90,140,.08); white-space: pre-line;
}
.solution-steps li::before {
  content: counter(step); position: absolute; left: 12px; top: 50%; transform: translateY(-50%);
  width: 28px; height: 28px; border-radius: 50%; background: var(--blue);
  color: #fff; font-weight: 900; display: grid; place-items: center; font-size: 15px;
}
.solution-final {
  margin-top: 6px; padding: 12px 16px; border-radius: 14px;
  background: #e2f8ee; border: 2px dashed var(--green); font-weight: 800; font-size: 17px;
}
.solution-final .lbl { color: var(--green-d); margin-right: 6px; }

.pd-nav { display: flex; justify-content: space-between; gap: 12px; margin-top: 22px; }

/* ---------- 统计（首页进度条） ---------- */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 14px; margin-top: 6px; }
.stat { padding: 18px; text-align: center; }
.stat b { display: block; font-size: 30px; color: var(--orange-d); }
.stat span { color: var(--ink-soft); font-size: 14.5px; }
.progress-bar { height: 16px; border-radius: 999px; background: #f1e8db; overflow: hidden; margin: 10px 0 4px; }
.progress-bar i { display: block; height: 100%; border-radius: 999px; background: linear-gradient(90deg, var(--yellow), var(--green)); transition: width .4s; }

/* ---------- 撒花 ---------- */
#confettiLayer { position: fixed; inset: 0; pointer-events: none; overflow: hidden; z-index: 99; }
.confetti-bit { position: absolute; top: -20px; font-size: 22px; animation: fall linear forwards; }
@keyframes fall {
  to { transform: translateY(110vh) rotate(720deg); opacity: .15; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 640px) {
  html { font-size: 16px; }
  main { width: calc(100% - 18px); padding-top: 14px; }
  .hero { padding: 14px 4px 22px; }
  .hero h1 { font-size: 24px; letter-spacing: 0; }
  .hero p { font-size: 15px; }

  /* 顶栏：缩小 logo 与导航，避免折行 */
  .site-header { padding: 8px 10px; gap: 8px; }
  .logo { gap: 7px; min-width: 0; }
  .logo-badge { font-size: 21px; width: 38px; height: 38px; border-radius: 12px; }
  .logo-text { font-size: 15px; letter-spacing: 0; line-height: 1.3; white-space: normal; }
  .logo-text em { display: block; font-style: normal; }
  .site-nav { gap: 6px; flex: none; }
  .site-nav a { padding: 6px 11px; font-size: 13.5px; }

  /* 分类横幅与筛选 */
  .cat-banner { padding: 14px; gap: 10px; border-left-width: 8px; }
  .cat-banner .cat-emoji { font-size: 34px; }
  .cat-banner h1 { font-size: 21px; }
  .cat-banner .cat-sub { font-size: 13px; }
  .cat-banner .banner-actions { margin-left: 0; width: 100%; }
  .filters { padding: 12px; gap: 8px; }
  .filters input[type=search] { margin-left: 0; width: 100%; order: -1; }
  .f-btn { font-size: 13.5px; padding: 4px 12px; }
  .sub-row { gap: 6px; }

  /* 列表项 */
  .p-item { padding: 12px; gap: 10px; }
  .p-num { width: 42px; height: 42px; border-radius: 12px; font-size: 13px; }
  .p-q { font-size: 14.5px; }
  .pager button { min-width: 36px; padding: 6px 9px; font-size: 14px; }

  /* 详情页 */
  .pd-top { gap: 8px; margin-bottom: 12px; }
  .pd-top .btn-sm { padding: 6px 12px; font-size: 13.5px; }
  .pd-progress { font-size: 12.5px; }
  .pd-main { padding: 16px 14px 20px; border-top-width: 8px; }
  .pd-question { font-size: 17px; line-height: 1.8; margin-bottom: 14px; }
  .answer-box { flex-direction: column; gap: 10px; margin-top: 16px; }
  .answer-box .field { min-width: 0; }
  .answer-box .btn { width: 100%; }
  .action-row { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 14px; }
  .action-row .btn { padding: 12px 6px; font-size: 15px; }
  .panel { padding: 14px; margin-top: 14px; }
  .solution-steps li { padding: 9px 9px 9px 46px; font-size: 15px; }
  .solution-final { font-size: 15.5px; }
  .pd-nav { margin-top: 16px; }
  .pd-nav .btn-sm { padding: 7px 12px; font-size: 13.5px; }
}