/* 科创营复习站 - 公共样式（适合 11 岁孩子：字大、色彩明快、一屏一件事） */
:root {
  --c: #3b6ef5;               /* 当前主题色（主题页会覆盖） */
  --bg: #f4f7fb;
  --card: #ffffff;
  --text: #24324a;
  --muted: #6b7a90;
  --ok: #1fa463;
  --ok-soft: #e3f6ec;
  --bad: #e5484d;
  --bad-soft: #fdecec;
  --warn-soft: #fff6dc;
  --radius: 18px;
  --shadow: 0 4px 16px rgba(30, 50, 90, .08);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  font-size: 18px;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
}
a { color: var(--c); }
.wrap { max-width: 900px; margin: 0 auto; padding: 0 16px 60px; }

/* 顶栏 */
.topbar { background: linear-gradient(120deg, #3b6ef5, #7a5cf5); color: #fff; padding: 26px 16px 44px; }
.topbar .wrap { padding-bottom: 0; }
.topbar h1 { margin: 0; font-size: 30px; line-height: 1.4; }
.topbar p { margin: 4px 0 0; opacity: .92; }
.topic-bar { background: var(--c); }
.back { color: #fff; text-decoration: none; opacity: .95; font-size: 16px; display: inline-block; margin-bottom: 4px; }
.back:hover { text-decoration: underline; }
main.wrap { margin-top: -22px; }

/* 主菜单 */
.linkbar { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.lesson-block { margin-top: 28px; }
.lesson-title { font-size: 24px; margin: 0 0 4px; display: flex; align-items: center; flex-wrap: wrap; gap: 10px; }
.lesson-title small { font-size: 14px; color: var(--muted); font-weight: normal; }
.lesson-no { background: #24324a; color: #fff; border-radius: 12px; padding: 0 14px; font-size: 20px; }
.group-title { font-size: 18px; color: var(--muted); margin: 16px 0 8px; }
.topic-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; }
.topic-card {
  display: flex; gap: 14px; align-items: center;
  background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 16px 18px; text-decoration: none; color: var(--text);
  border-left: 8px solid var(--c);
  transition: transform .15s, box-shadow .15s;
}
.topic-card:hover { transform: translateY(-3px); box-shadow: 0 8px 24px rgba(30, 50, 90, .15); }
.topic-card .ico { font-size: 40px; line-height: 1; }
.topic-card .tt { font-size: 19px; font-weight: bold; line-height: 1.4; }
.topic-card .dd { font-size: 14px; color: var(--muted); line-height: 1.5; }
.topic-card .best { font-size: 14px; color: var(--ok); font-weight: bold; }

/* 标签 */
.tabs { display: flex; gap: 8px; margin: 0 0 18px; flex-wrap: wrap; }
.tab {
  border: none; background: var(--card); box-shadow: var(--shadow);
  padding: 10px 18px; border-radius: 30px; font-size: 17px; cursor: pointer;
  color: var(--text); font-family: inherit;
}
.tab.active { background: var(--c); color: #fff; }
.panel { display: none; }
.panel.active { display: block; }

/* 卡片 */
.card { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 20px 24px; margin-bottom: 18px; }
.step-title { margin: 0 0 10px; font-size: 24px; color: var(--c); line-height: 1.4; }
.step-title .subject { display: none; }
.subject { display: inline-block; background: var(--warn-soft); border-radius: 6px; padding: 0 8px; font-size: 13px; margin-right: 6px; }
.goal { background: #eef3ff; border-radius: 12px; padding: 12px 16px; margin: 8px 0; }
.tip { background: var(--warn-soft); border-radius: 12px; padding: 12px 16px; margin: 12px 0; }
.tip::before { content: "💡 "; }
.step p, .step li { margin: 8px 0; }
.step ul, .step ol { padding-left: 24px; }
table { border-collapse: collapse; width: 100%; margin: 10px 0; font-size: 16px; }
th, td { border: 1px solid #dfe5ef; padding: 5px 10px; text-align: left; vertical-align: top; }
th { background: #f0f4fb; }
code { font-family: Consolas, "Courier New", monospace; background: #f0f3f8; padding: 1px 6px; border-radius: 4px; }
pre { background: #1e2433; color: #e8ecf5; padding: 12px 16px; border-radius: 12px; overflow-x: auto; font-size: 16px; line-height: 1.6; }
pre code { background: none; padding: 0; color: inherit; }
.hint { color: var(--muted); font-size: 16px; text-align: center; margin: 0 0 8px; }

/* 进度条与导航 */
.progress { height: 12px; background: #e3e9f3; border-radius: 10px; overflow: hidden; margin-bottom: 6px; }
.progress div { height: 100%; background: var(--c); border-radius: 10px; transition: width .3s; }
.qcount { color: var(--muted); font-size: 15px; margin-bottom: 10px; }
.nav { display: flex; gap: 12px; justify-content: center; align-items: center; flex-wrap: wrap; margin: 14px 0 4px; }
.btn {
  border: none; background: var(--c); color: #fff; font-family: inherit; text-decoration: none;
  padding: 11px 24px; border-radius: 14px; font-size: 18px; cursor: pointer; display: inline-block; line-height: 1.5;
}
.btn:hover { filter: brightness(1.08); }
.btn.ghost { background: #e9eef8; color: #3a4a66; }
.btn:disabled { opacity: .4; cursor: not-allowed; }

/* 原始资料图片 */
.photos { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; }
.photos figure { margin: 0; background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; cursor: zoom-in; }
.photos img { width: 100%; height: 220px; object-fit: cover; display: block; }
.photos figcaption { padding: 8px 12px; font-size: 14px; color: var(--muted); }
.lightbox { position: fixed; inset: 0; background: rgba(0, 0, 0, .85); display: none; align-items: center; justify-content: center; z-index: 99; cursor: zoom-out; overflow: auto; }
.lightbox.show { display: flex; }
.lightbox img { max-width: 96vw; max-height: 96vh; }

/* 记忆卡片 */
.flash-wrap { display: flex; flex-direction: column; align-items: stretch; }
.flash { width: 100%; max-width: 600px; margin: 0 auto; min-height: 240px; perspective: 1000px; cursor: pointer; }
.flash-inner { position: relative; width: 100%; min-height: 240px; transition: transform .5s; transform-style: preserve-3d; }
.flash.flipped .flash-inner { transform: rotateY(180deg); }
.flash-face {
  position: absolute; inset: 0; backface-visibility: hidden; border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center; text-align: center;
  padding: 24px; font-size: 22px; line-height: 1.7;
}
.flash-front { background: #fff; border: 3px solid var(--c); }
.flash-back { background: var(--ok-soft); border: 3px solid var(--ok); transform: rotateY(180deg); font-size: 20px; }

/* 测验 */
.q-title { font-size: 21px; font-weight: bold; margin: 6px 0 14px; line-height: 1.7; }
.opts { display: grid; gap: 10px; }
.opt {
  display: flex; gap: 12px; align-items: center; text-align: left; font-family: inherit; font-size: 19px;
  border: 2px solid #dfe5ef; border-radius: 14px; padding: 10px 14px; background: #fff; cursor: pointer; color: var(--text);
}
.opt b { background: #eef3ff; color: var(--c); border-radius: 50%; width: 32px; height: 32px; display: inline-flex; align-items: center; justify-content: center; flex: none; }
.opt:hover:not(:disabled) { border-color: var(--c); background: #f8faff; }
.opt.correct { background: var(--ok-soft); border-color: var(--ok); }
.opt.chosen-wrong { background: var(--bad-soft); border-color: var(--bad); }
.fill-row { display: flex; gap: 10px; flex-wrap: wrap; }
.fill { padding: 10px 14px; border: 2px solid #c9d2e0; border-radius: 12px; font-size: 20px; width: 240px; max-width: 100%; font-family: inherit; }
.fill:focus { outline: none; border-color: var(--c); }
.fb { font-size: 21px; font-weight: bold; margin: 16px 0 6px; padding: 10px 16px; border-radius: 12px; }
.fb.ok { background: var(--ok-soft); color: var(--ok); }
.fb.bad { background: var(--bad-soft); color: var(--bad); }
.explain { background: #f6f8fc; border-radius: 12px; padding: 10px 16px; font-size: 17px; }
.result { text-align: center; padding: 20px 0 6px; }
.result .big { font-size: 56px; font-weight: bold; color: var(--c); line-height: 1.2; }
.result .stars { font-size: 36px; min-height: 44px; }

.footer-note { color: var(--muted); font-size: 13px; text-align: center; margin-top: 30px; }

@media (max-width: 600px) {
  body { font-size: 17px; }
  .topbar h1 { font-size: 24px; }
  .card { padding: 16px; }
  .step-title { font-size: 21px; }
}