/* ==========================================================================
   银龄昆曲 · 昆曲康养新模式  ——  适老化单页网站样式
   设计要点：大字号、高对比度、少动画、按钮够大、锚点滚动不被导航遮挡
   ========================================================================== */

/* ---------- 1. 基础变量 ---------- */
:root {
  /* 主色：低饱和青绿（取自昆曲插图），深色以保证对比度 */
  --ink:        #14201f;   /* 正文文字：近黑 */
  --ink-soft:   #3c4a48;   /* 次级文字 */
  --brand:      #1f5148;   /* 主色：深青绿 */
  --brand-mid:  #2f7a68;
  --brand-soft: #e7f0ec;   /* 浅色底 */
  --tint:       #f4f8f5;   /* 板块交替底色 */
  --paper:      #fdfbf6;   /* 纸张底色 */
  --line:       #cddbd5;
  --warn:       #a8551f;
  --radius:     14px;
  --shadow:     0 2px 10px rgba(20, 32, 31, .07);
  --shadow-lg:  0 6px 24px rgba(20, 32, 31, .12);
  --maxw:       1120px;
  /* 导航栏占位高度：
     --nav-h      = 导航栏自身的高度（固定值，绝不随测量结果变化）
     --nav-offset = 供内容让位与锚点定位使用的实际高度（由脚本测量，手机端展开菜单时会变） */
  --nav-h:      78px;
  --nav-offset: 78px;
  --font-step:  0;         /* 由 JS 调整字号时使用 */
}

/* ---------- 2. 重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  /* 适老化基准字号：桌面 20px，配合 root 缩放 */
  font-size: calc(20px + var(--font-step) * 1px);
  scroll-behavior: smooth;
  /* 锚点滚动时避开固定导航 */
  scroll-padding-top: calc(var(--nav-offset) + 12px);
  -webkit-text-size-adjust: 100%;
}

@media (max-width: 720px) {
  html { font-size: calc(18px + var(--font-step) * 1px); }
}

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB",
               "Source Han Sans SC", "Noto Sans CJK SC", "Heiti SC",
               system-ui, -apple-system, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.75;           /* 行间距 > 1.3，实际约 1.75 */
  letter-spacing: .01em;
}

img { max-width: 100%; height: auto; display: block; }

h1, h2, h3, h4 { line-height: 1.35; margin: 0 0 .6em; font-weight: 700; }

p { margin: 0 0 1em; }

a { color: var(--brand); text-underline-offset: .18em; }
a:hover { color: var(--brand-mid); }

strong { font-weight: 700; color: var(--ink); }

kbd {
  font-family: Consolas, monospace;
  background: #eef3f0; border: 1px solid var(--line);
  border-radius: 5px; padding: .05em .45em; font-size: .9em;
}

code {
  font-family: Consolas, monospace;
  background: #eef3f0; padding: .1em .4em; border-radius: 5px; font-size: .92em;
}

/* 键盘可达的焦点环 —— 无障碍必备 */
:focus-visible {
  outline: 3px solid #d9822b;
  outline-offset: 3px;
  border-radius: 6px;
}

/* 跳到主要内容 */
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 999;
  background: var(--brand); color: #fff; padding: .7em 1.2em;
  font-weight: 700; border-radius: 0 0 10px 0;
}
.skip-link:focus { left: 0; color: #fff; }

/* ---------- 3. 顶部固定导航栏 ---------- */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(253, 251, 246, .98);
  border-bottom: 2px solid var(--line);
  box-shadow: 0 2px 12px rgba(20, 32, 31, .06);
  backdrop-filter: saturate(150%) blur(6px);
}

.topbar-inner {
  max-width: var(--maxw); margin: 0 auto;
  padding: .5rem 1.1rem;
  display: flex; align-items: center; gap: .9rem;
  min-height: var(--nav-h);
}

.brand {
  display: flex; align-items: center; gap: .55rem;
  text-decoration: none; color: var(--brand); flex: 0 0 auto;
}
.brand-mark {
  width: 2.3rem; height: 2.3rem; flex: 0 0 auto;
  display: grid; place-items: center;
  background: var(--brand); color: #fff;
  border-radius: 50%; font-size: 1.15rem; font-weight: 700;
}
.brand-text {
  font-weight: 700; font-size: 1.05rem; line-height: 1.2;
  display: flex; flex-direction: column;
}
.brand-text em {
  font-style: normal; font-size: .68rem; font-weight: 500;
  color: var(--ink-soft); letter-spacing: .12em;
}

.nav {
  display: flex; flex-wrap: wrap; gap: .25rem;
  margin-left: auto;
}
.nav a {
  display: block; padding: .55em .8em;
  font-size: 1rem; font-weight: 600;
  color: var(--ink); text-decoration: none;
  border-radius: 8px; white-space: nowrap;
  border-bottom: 3px solid transparent;
}
.nav a:hover { background: var(--brand-soft); color: var(--brand); }
.nav a.is-active {
  color: var(--brand); border-bottom-color: var(--brand);
  background: var(--brand-soft);
}

.tools { display: flex; gap: .35rem; flex: 0 0 auto; }
.tool-btn {
  font-family: inherit; font-size: .92rem; font-weight: 700;
  min-width: 3.1rem; min-height: 2.7rem;   /* 触控目标够大 */
  padding: .35em .6em;
  color: var(--brand); background: #fff;
  border: 2px solid var(--brand-mid); border-radius: 10px;
  cursor: pointer;
}
.tool-btn:hover { background: var(--brand-soft); }
.tool-btn[aria-pressed="true"] { background: var(--brand); color: #fff; }
.tool-btn--wide { min-width: 5.2rem; }

/* 移动端：导航折叠按钮 */
.navtoggle-wrap { display: none; padding: 0 1.1rem .5rem; }
.navtoggle {
  font-family: inherit; font-size: 1rem; font-weight: 700;
  width: 100%; padding: .6em 1em; cursor: pointer;
  color: var(--brand); background: var(--brand-soft);
  border: 2px solid var(--brand-mid); border-radius: 10px;
}

/* ---------- 4. 通用板块骨架 ---------- */
main { padding-top: var(--nav-offset); }

.section { padding: 3.4rem 0 3.8rem; }
.section--tint { background: var(--tint); }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 1.1rem; }

.eyebrow {
  margin: 0 0 .35em; font-size: .82rem; font-weight: 700;
  letter-spacing: .3em; color: var(--brand-mid); text-transform: uppercase;
}

.section-title {
  font-size: 2.05rem; color: var(--brand);
  margin: 0 0 .5rem; position: relative; padding-bottom: .4rem;
}
.section-title::after {
  content: ""; position: absolute; left: 0; bottom: 0;
  width: 4.5rem; height: 5px; border-radius: 3px;
  background: linear-gradient(90deg, var(--brand-mid), #b8d6ca);
}

.section-lead {
  font-size: 1.08rem; color: var(--ink-soft);
  max-width: 62ch; margin-bottom: 2rem;
}

.sub-title {
  font-size: 1.32rem; color: var(--brand);
  margin: 2.6rem 0 1rem; padding-left: .7rem;
  border-left: 6px solid var(--brand-mid);
  line-height: 1.45;
}

/* ---------- 5. 板块一：首屏 ---------- */
.hero {
  position: relative;
  display: grid; grid-template-columns: 1.15fr .85fr;
  gap: 2rem; align-items: center;
  max-width: var(--maxw); margin: 0 auto;
  padding: 3rem 1.1rem 4.2rem;
}

.hero-kicker {
  display: inline-block; margin: 0 0 1rem;
  font-size: .85rem; font-weight: 700; letter-spacing: .1em;
  color: var(--brand); background: var(--brand-soft);
  padding: .35em 1em; border-radius: 100px;
  border: 1px solid var(--line);
}

.hero-title {
  font-size: 2.9rem; line-height: 1.25; color: var(--brand);
  margin: 0 0 .8rem;
}
.hero-title-sub {
  display: block; font-size: 1.35rem; font-weight: 600;
  color: var(--ink); margin-top: .5rem; line-height: 1.6;
}

.hero-slogan {
  font-size: 1.35rem; font-weight: 700; color: var(--ink);
  margin: 0 0 .8rem;
}
.hero-slogan::before {
  content: "“"; color: var(--brand-mid); font-size: 1.4em; line-height: 0;
}
.hero-slogan::after {
  content: "”"; color: var(--brand-mid); font-size: 1.4em; line-height: 0;
}

.hero-lead { font-size: 1.08rem; color: var(--ink-soft); max-width: 46ch; }

.hero-actions { display: flex; flex-wrap: wrap; gap: .8rem; margin: 1.6rem 0 .8rem; }
.hero-hint { font-size: .92rem; color: var(--ink-soft); margin: 0; }

.hero-art {
  margin: 0; border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-lg); border: 6px solid #fff;
  background: #fff;
}
.hero-art img { width: 100%; }

.scroll-cue {
  position: absolute; left: 50%; bottom: .9rem; transform: translateX(-50%);
  font-size: .88rem; color: var(--brand-mid); letter-spacing: .1em;
  animation: bob 2.2s ease-in-out infinite;
}
@keyframes bob { 0%,100% { transform: translate(-50%, 0); } 50% { transform: translate(-50%, 6px); } }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .scroll-cue { animation: none; }
  * { transition: none !important; }
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: .4em;
  font-family: inherit; font-size: 1rem; font-weight: 700;
  min-height: 3rem; padding: .6em 1.4em;
  color: var(--brand); background: #fff;
  border: 2px solid var(--brand-mid); border-radius: 100px;
  text-decoration: none; cursor: pointer;
  box-shadow: var(--shadow);
}
.btn:hover { background: var(--brand-soft); color: var(--brand); }
.btn--primary { background: var(--brand); color: #fff; border-color: var(--brand); }
.btn--primary:hover { background: var(--brand-mid); color: #fff; }

.download-row { display: flex; flex-wrap: wrap; gap: .8rem; margin: 1rem 0; }

/* ---------- 7. 卡片与网格 ---------- */
.grid { display: grid; gap: 1.3rem; }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }

.card {
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1.5rem 1.6rem;
  box-shadow: var(--shadow);
}
.card p:last-child { margin-bottom: 0; }

.card-title {
  font-size: 1.22rem; color: var(--brand);
  display: flex; align-items: center; gap: .55rem;
  margin-bottom: .7rem;
}
.card-title .num {
  width: 1.8rem; height: 1.8rem; flex: 0 0 auto;
  display: grid; place-items: center; border-radius: 50%;
  background: var(--brand); color: #fff; font-size: .95rem;
}

.card--accent { border-top: 5px solid var(--brand-mid); }
.card--accent h4 { font-size: 1.18rem; color: var(--brand); margin-bottom: .5rem; }
.card-icon { font-size: 1.9rem; margin: 0 0 .4rem; line-height: 1; }

.card--lead { border-left: 6px solid var(--brand-mid); }
.card--lead h4 { font-size: 1.28rem; color: var(--brand); }

/* 清单 */
.checklist { list-style: none; padding: 0; margin: 0 0 1.2rem; }
.checklist li {
  position: relative; padding-left: 2em; margin-bottom: .6em;
  font-size: 1.05rem;
}
.checklist li::before {
  content: "✓"; position: absolute; left: 0; top: 0;
  width: 1.45em; height: 1.45em; line-height: 1.45em;
  text-align: center; border-radius: 50%;
  background: var(--brand-soft); color: var(--brand);
  font-weight: 700; font-size: .95em; border: 1px solid var(--brand-mid);
}

/* 带图标清单 */
.icon-list { list-style: none; padding: 0; margin: 0; }
.icon-list li {
  display: flex; gap: .8rem; align-items: flex-start;
  padding: .7rem 0; border-bottom: 1px dashed var(--line);
}
.icon-list li:last-child { border-bottom: 0; }
.icon-list li > span { font-size: 1.5rem; line-height: 1.4; flex: 0 0 auto; }
.icon-list div { font-size: 1.05rem; }

/* 提示条 */
.notice {
  background: #fff8e8; border: 2px solid #efd9a4;
  border-left: 7px solid #d9a441;
  border-radius: 10px; padding: 1rem 1.2rem;
  font-size: 1rem; margin: 1.4rem 0;
}
.notice--work { background: #eef5f2; border-color: #bcd8cd; border-left-color: var(--brand-mid); }
.note-small { font-size: .92rem; color: var(--ink-soft); }

/* 步骤列表 */
.steps { counter-reset: step; list-style: none; padding: 0; margin: 0; }
.steps li {
  counter-increment: step; position: relative;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.1rem 1.3rem 1.1rem 3.6rem; margin-bottom: .9rem;
  box-shadow: var(--shadow); font-size: 1.05rem;
}
.steps li::before {
  content: counter(step);
  position: absolute; left: 1.1rem; top: 1.05rem;
  width: 1.9rem; height: 1.9rem; border-radius: 50%;
  display: grid; place-items: center;
  background: var(--brand); color: #fff; font-weight: 700; font-size: .95rem;
}

/* ---------- 8. 调研数据可视化 ---------- */
.stat-row {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 1rem; margin: 0 0 1.6rem;
}
.stat {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.1rem 1rem; text-align: center; box-shadow: var(--shadow);
}
.stat strong {
  display: block; font-size: 2.1rem; color: var(--brand);
  line-height: 1.15;
}
.stat strong small { font-size: .45em; font-weight: 600; margin-left: .15em; }
.stat span { display: block; font-size: .92rem; color: var(--ink-soft); margin-top: .3rem; }

.finding { display: flex; flex-direction: column; }
.finding-title {
  font-size: 1.18rem; color: var(--brand);
  padding-bottom: .5rem; border-bottom: 2px solid var(--brand-soft);
  margin-bottom: 1rem;
}
.finding-note {
  margin: auto 0 0; padding-top: .9rem;
  font-size: .98rem; color: var(--ink-soft);
  border-top: 1px dashed var(--line);
}

/* 横向条形图 */
.bars { display: flex; flex-direction: column; gap: .95rem; }
.bar-row {
  display: grid;
  grid-template-columns: minmax(9rem, 1.25fr) 2fr auto;
  gap: .7rem; align-items: center;
}
.bar-label { font-size: .95rem; line-height: 1.45; }
.bar-track {
  display: block; height: 1.15rem; border-radius: 100px;
  background: #e9efec; overflow: hidden;
  border: 1px solid var(--line);
}
.bar-fill {
  display: block; height: 100%; border-radius: 100px;
  background: linear-gradient(90deg, var(--brand-mid), #7fb9a5);
}
.bar-fill--warn { background: linear-gradient(90deg, #c9812f, #e0b070); }
.bar-value {
  font-size: 1rem; font-weight: 700; color: var(--brand);
  min-width: 4.2em; text-align: right;
}

/* 环形图（纯 CSS，无依赖） */
.donut-wrap { display: flex; align-items: center; gap: 1.4rem; flex-wrap: wrap; }
.donut {
  --a: 58.4%;
  width: 8.2rem; height: 8.2rem; flex: 0 0 auto;
  border-radius: 50%; position: relative;
  background: conic-gradient(var(--brand-mid) 0 var(--a), #e2c98f var(--a) 95.1%, #cbb9ae 95.1% 100%);
}
.donut::after {
  content: ""; position: absolute; inset: 21%;
  background: #fff; border-radius: 50%;
}
.donut span {
  position: absolute; inset: 0; display: grid; place-items: center;
  font-size: 1.45rem; font-weight: 700; color: var(--brand); z-index: 1;
}
.donut-legend p {
  margin: 0 0 .5rem; font-size: .98rem;
  display: flex; align-items: center; gap: .5rem;
}
.dot { width: .9rem; height: .9rem; border-radius: 50%; flex: 0 0 auto; }
.dot--on  { background: var(--brand-mid); }
.dot--off { background: #e2c98f; }
.dot--no  { background: #cbb9ae; }

/* ---------- 9. 视频板块 ---------- */
/* 三个模块内容形态不同：模块1 视频、模块2 纯文字、模块3 网盘链接，
   所以用两列网格，卡片高度自动对齐 */
.video-grid {
  display: grid; gap: 1.4rem;
  grid-template-columns: repeat(2, 1fr);
  align-items: stretch;
}
.video-card { display: flex; flex-direction: column; padding: 1.1rem; }
.video-box {
  position: relative; width: 100%; aspect-ratio: 16 / 9;
  border-radius: 10px; overflow: hidden;
  background: #10201d; margin-bottom: 1rem;
}
.video-box video, .video-box iframe {
  position: absolute; inset: 0; width: 100%; height: 100%; border: 0;
}
.video-placeholder {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: .35rem; text-align: center; padding: 1rem;
  background: repeating-linear-gradient(45deg, #16292550 0 14px, #10201d 14px 28px);
  color: #eaf3ef;
}
.play-icon {
  width: 4rem; height: 4rem; border-radius: 50%;
  display: grid; place-items: center; font-size: 1.5rem;
  background: rgba(255, 255, 255, .14);
  border: 3px solid rgba(255, 255, 255, .55);
  color: #fff; padding-left: .18em;
}
.video-ph { margin: .35rem 0 0; font-size: 1.05rem; font-weight: 700; }
.video-ph-sub { margin: 0; font-size: .84rem; color: #b9d2ca; line-height: 1.5; max-width: 30ch; }

.video-title { font-size: 1.15rem; color: var(--brand); margin-bottom: .3rem; }
.video-tag {
  display: inline-block; font-size: .8rem; font-weight: 700;
  color: var(--brand); background: var(--brand-soft);
  border: 1px solid var(--line); border-radius: 100px;
  padding: .12em .8em; margin: 0 0 .6rem;
}
.video-card > p:last-child { font-size: .98rem; color: var(--ink-soft); margin: 0; }

/* 模块 2：没有视频窗口，用文字留白版式撑起卡片 */
.video-card--text { justify-content: flex-start; }
.video-card--text .video-card-note {
  margin: auto 0 0; padding-top: .8rem;
  font-size: .92rem; color: var(--brand);
  border-top: 1px dashed var(--line);
}

/* 模块 3：网盘卡片，用与视频窗口同比例的深色面板保持视觉一致 */
.netdisk-box {
  aspect-ratio: 16 / 9; width: 100%;
  border-radius: 10px; margin-bottom: 1rem;
  background: linear-gradient(150deg, #17302b, #10201d);
  border: 1px solid #2c4a43;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: .5rem; padding: 1rem 1.2rem; text-align: center;
}
.netdisk-icon { font-size: 2rem; line-height: 1; }
.netdisk-box .video-ph { margin: 0; color: #eaf3ef; }
.netdisk-code { margin: 0; font-size: .95rem; color: #cfe3db; }
.netdisk-code strong {
  color: #fff; font-size: 1.15em; letter-spacing: .08em;
  background: rgba(255, 255, 255, .16);
  border-radius: 6px; padding: .05em .45em;
}
.netdisk-btn {
  margin-top: .2rem; font-size: .95rem;
  min-height: 2.9rem; padding: .5em 1.1em;
}
.netdisk-box .video-ph-sub {
  color: #a8c4bb; max-width: 26ch; font-size: .8rem;
}

/* ---------- 10. 图文教学：手势 ---------- */
.practice-tip {
  background: var(--brand-soft); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1.1rem 1.3rem; font-size: 1.02rem;
}

.gesture-grid { display: grid; gap: 1.5rem; }

.gesture {
  margin: 0; display: grid; grid-template-columns: minmax(0, 340px) 1fr;
  gap: 1.6rem; align-items: start;
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1.4rem;
  box-shadow: var(--shadow);
}
.gesture img {
  width: 100%; border-radius: 10px;
  border: 1px solid var(--line); background: var(--paper);
}
.gesture figcaption { min-width: 0; }
.gesture h4 { font-size: 1.3rem; color: var(--brand); margin-bottom: .7rem; }
.gesture ol, .gesture ul { padding-left: 1.4em; margin: 0 0 .8rem; }
.gesture li { margin-bottom: .4em; font-size: 1.02rem; }
.gesture p { font-size: 1.02rem; margin-bottom: .7rem; }
.gesture p:last-child { margin-bottom: 0; }

.gesture-use {
  background: var(--brand-soft); border-left: 5px solid var(--brand-mid);
  border-radius: 0 8px 8px 0; padding: .7rem .9rem;
  font-size: .98rem !important; color: var(--ink-soft);
}
.poses { list-style: none; padding: 0; }
.poses li {
  padding: .55rem 0 .55rem 1.2rem; position: relative;
  border-bottom: 1px dashed var(--line);
}
.poses li:last-child { border-bottom: 0; }
.poses li::before {
  content: "◆"; position: absolute; left: 0; color: var(--brand-mid); font-size: .8em;
}

/* ---------- 11. 家属辅助指南 ---------- */
.card--help { border: 2px solid var(--brand-mid); background: #fbfdfb; }
.help-for {
  font-size: 1.1rem; font-weight: 700; color: var(--brand);
  margin-bottom: 1rem;
}

/* ---------- 12. 页脚 ---------- */
.footer {
  background: var(--brand); color: #e9f2ee;
  padding: 2.6rem 0 2.2rem; margin-top: 0;
}
.footer .wrap { max-width: var(--maxw); }
.footer p { margin: 0 0 .6rem; font-size: .98rem; }
.footer-title { font-size: 1.18rem; font-weight: 700; color: #fff; }
.footer strong { color: #fff; }
.footer-meta { line-height: 1.9; }
.footer-note { font-size: .88rem; color: #b6cfc7; margin-top: 1rem; }
/* 联系邮箱：深色页脚上用浅色高对比，可直接点击发邮件 */
.footer-mail {
  color: #fff; font-weight: 700; text-decoration: underline;
  text-decoration-thickness: 2px; text-underline-offset: .2em;
  word-break: break-all;
}
.footer-mail:hover { color: #bfe3d7; }

/* ---------- 13. 回到顶部 ---------- */
.totop {
  position: fixed; right: 1.1rem; bottom: 1.1rem; z-index: 90;
  width: 3.2rem; height: 3.2rem; border-radius: 50%;
  display: grid; place-items: center;
  font-size: 1.5rem; font-weight: 700; text-decoration: none;
  background: var(--brand); color: #fff;
  box-shadow: var(--shadow-lg);
  opacity: 0; visibility: hidden; transition: opacity .25s;
}
.totop.is-shown { opacity: 1; visibility: visible; }
.totop:hover { background: var(--brand-mid); color: #fff; }

/* ==========================================================================
   14. 响应式：手机端自动适配纵向布局
   ========================================================================== */
@media (max-width: 980px) {
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .video-grid { grid-template-columns: 1fr; }
  .stat-row { grid-template-columns: repeat(2, 1fr); }
  .hero { grid-template-columns: 1fr; padding-top: 2.2rem; }
  .hero-art { order: -1; max-width: 560px; }
  .hero-title { font-size: 2.35rem; }
}

@media (max-width: 720px) {
  :root { --nav-h: 62px; --nav-offset: 62px; }

  /* 导航栏转为横向紧凑排列 */
  .topbar-inner { padding: .4rem .7rem; gap: .4rem; }
  .brand { gap: .3rem; }
  .brand-text { display: none; }
  .brand-mark { width: 2rem; height: 2rem; font-size: .95rem; }
  .tools { margin-left: auto; gap: .3rem; }
  .tool-btn {
    min-width: 2.5rem; min-height: 2.4rem;
    font-size: .85rem; padding: .3em .35em;
  }
  .tool-btn--wide { min-width: 4rem; font-size: .8rem; }

  /* 手机端按钮不必占满整行，但触控目标仍然够大 */
  .btn { width: auto; max-width: 100%; }
  .download-row .btn { width: 100%; }

  .navtoggle-wrap { display: block; }
  .nav {
    display: none; width: 100%; margin: 0;
    padding: 0 1.1rem .6rem; gap: .3rem;
    flex-direction: column;
  }
  .nav.is-open { display: flex; }
  .nav a {
    border-bottom: 1px solid var(--line); border-radius: 8px;
    padding: .7em .9em; font-size: 1.05rem;
  }
  .nav a.is-active { border-bottom-color: var(--brand); }
  /* 手机端导航展开后由脚本测量实际高度并写入 --nav-offset */

  .section { padding: 2.4rem 0 2.8rem; }
  .section-title { font-size: 1.7rem; }
  .hero-title { font-size: 1.95rem; }
  .hero-title-sub { font-size: 1.15rem; }
  .hero-slogan { font-size: 1.15rem; }

  .grid--2, .grid--3 { grid-template-columns: 1fr; }
  .stat-row { grid-template-columns: repeat(2, 1fr); }
  .stat strong { font-size: 1.7rem; }

  .gesture { grid-template-columns: 1fr; }
  .gesture img { max-width: 420px; margin: 0 auto; }

  .bar-row { grid-template-columns: 1fr auto; }
  .bar-label { grid-column: 1 / -1; }
  .bar-value { grid-column: 2; }
  .bar-track { grid-column: 1; }

  .donut-wrap { justify-content: center; }
  .download-row { flex-direction: column; }
  .totop { right: .7rem; bottom: .7rem; width: 2.8rem; height: 2.8rem; font-size: 1.3rem; }
}

/* 超窄屏（老式手机、平板分屏）：进一步压缩顶部工具区 */
@media (max-width: 420px) {
  .brand-mark { width: 1.8rem; height: 1.8rem; font-size: .85rem; }
  .tool-btn { min-width: 2.3rem; min-height: 2.3rem; font-size: .8rem; padding: .25em .25em; }
  .tool-btn--wide { min-width: 3.6rem; font-size: .75rem; }
  .topbar-inner { padding: .35rem .55rem; }
}

/* ==========================================================================
   15. 打印样式：供社区打印纸质材料
   ========================================================================== */
@media print {
  .topbar, .totop, .tools, .navtoggle-wrap, .skip-link, .scroll-cue, .hero-actions { display: none !important; }
  html { font-size: 12pt; scroll-padding-top: 0; }
  body { background: #fff; color: #000; }
  main { padding-top: 0; }
  .section { padding: 0 0 1rem; break-inside: avoid; }
  .section--tint { background: #fff; }
  .card, .gesture, .stat, .steps li { box-shadow: none; border: 1px solid #999; break-inside: avoid; }
  .hero { display: block; padding: 0 0 1rem; }
  .hero-art { max-width: 60%; border: 0; }
  .gesture { grid-template-columns: 200px 1fr; }
  .footer { background: #fff; color: #000; border-top: 2px solid #000; }
  .footer-title, .footer strong { color: #000; }
  .footer-mail { color: #000; text-decoration: none; }
  a { color: #000; text-decoration: none; }
  /* 不打印裸网址：长辈打印纸质材料时，长链接会让版式很乱；
     页面上已经提示了网盘链接打不开时如何操作 */
}