/* ============================================================================
   Science Teacher Helper - marketing site stylesheet
   ----------------------------------------------------------------------------
   2026-09-28 第二版：从"通用 SaaS 落地页"改成**教科书/数据表**的样子。
   为什么这么改：上一版是渐变 hero + 大圆角 + 阴影卡片 + 彩色胶囊，那一套是模板站的默认长相，
   看一眼就知道不是人做的。这一版的做法：

     * 标题用衬线（系统自带 Georgia 一系），正文用系统无衬线 - 像印出来的资料，不像落地页；
     * 分隔主要靠 **1px 发丝线**（--line），阴影只留给粘性页头与弹出层；
     * 胶囊改成**小号大写字 + 字距**（规格表里的字段名），不再用彩色药丸；
     * 背景是**中性灰**（--bg-soft），不是蓝调；强调色只在真需要抓眼睛的地方出现；
     * 数字一律 tabular-nums、表格右对齐 - 数据对得齐，是"人做的"最直观的信号；
     * 渐变只留页头玻璃一处；蓝色横幅改成纯色。

   类名是**接口**（构建器直接产出 .wrap/.card/.btn/.grid.two/figure/figcaption 等），
   改样式可以，改名要先看 tools/build_web.py。没有框架、没有外链字体、没有 CDN。
   ========================================================================== */

:root {
  --ink: #10161f;
  --ink-soft: #38424f;
  --muted: #5c6b7c;
  --line: #e4e8ee;
  --line-strong: #cbd3dd;
  --bg: #ffffff;
  --bg-soft: #f7f8fa;
  --bg-tint: #f1f4f8;
  --brand: #1d5ef0;
  --brand-deep: #1747b8;
  --brand-soft: #e9efff;
  --accent: #b25e09;
  --good: #17603a;
  --warn: #8a5300;
  --radius: 10px;
  --radius-sm: 6px;
  --shadow: 0 1px 0 rgba(16, 22, 31, .04);
  --shadow-lg: 0 6px 24px -14px rgba(16, 22, 31, .22);
  --wrap: 1140px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --serif: Georgia, "Iowan Old Style", "Times New Roman", Times, serif;
  --mono: ui-monospace, SFMono-Regular, "Cascadia Mono", Consolas, "Liberation Mono", monospace;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.62;
  color: var(--ink-soft);
  background: var(--bg);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

img, svg { max-width: 100%; height: auto; }

::selection { background: #d9e3fb; color: var(--ink); }

a { color: var(--brand); text-decoration: none; }
a:hover { color: var(--brand-deep); }
/* 正文里的链接带下划线（编辑排版的做法）；按钮/导航/页脚不带 - 那里下划线只是噪音 */
main a:not(.btn), .lead a { text-decoration: underline; text-decoration-thickness: 1px;
  text-decoration-color: var(--line-strong); text-underline-offset: 2px; }
main a:not(.btn):hover, .lead a:hover { text-decoration-color: currentColor; }
a:focus-visible, .btn:focus-visible, summary:focus-visible, label.nav-toggle:focus-visible {
  outline: 2px solid var(--brand); outline-offset: 2px; border-radius: 3px;
}

h1, h2, h3, h4 { color: var(--ink); font-family: var(--serif); font-weight: 600; margin: 0 0 .5em;
  letter-spacing: -.005em; line-height: 1.2; text-wrap: balance; }
h1 { font-size: clamp(2rem, 1.4rem + 2.2vw, 3.05rem); line-height: 1.12; }
h2 { font-size: clamp(1.4rem, 1.1rem + 1.1vw, 1.95rem); }
h3 { font-size: 1.16rem; }
h4 { font-size: .95rem; font-family: var(--font); font-weight: 700; }
p { margin: 0 0 1.05em; text-wrap: pretty; }
ul, ol { margin: 0 0 1.05em; padding-left: 1.25em; }
li { margin: .3em 0; }
strong { color: var(--ink); font-weight: 650; }
code, kbd, samp { font-family: var(--mono); font-size: .88em; background: var(--bg-tint);
  border: 1px solid var(--line); border-radius: 4px; padding: .08em .35em; color: var(--ink); }
hr { border: 0; border-top: 1px solid var(--line); margin: 2.4rem 0; }
small { font-size: .88rem; }
/* 大写字 + 字距的小标签：像规格表里的字段名。整站用它替代彩色胶囊。 */
.eyebrow { display: inline-block; font-size: .74rem; font-weight: 700; letter-spacing: .12em;
  text-transform: uppercase; color: var(--muted); margin: 0 0 .7rem; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 22px; }
.skip { position: absolute; left: -9999px; top: 0; background: var(--brand); color: #fff;
  padding: .6rem 1rem; border-radius: 0 0 var(--radius-sm) 0; z-index: 50; }
.skip:focus { left: 0; color: #fff; }

/* ---------------------------------------------------------------- 头部 ---------- */
header.site {
  position: sticky; top: 0; z-index: 30;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: saturate(150%) blur(10px);
  border-bottom: 1px solid var(--line);
}
header.site .wrap { display: flex; align-items: center; gap: 22px; min-height: 66px; }
a.brand { display: inline-flex; align-items: center; gap: .55rem; font-weight: 650; color: var(--ink);
  font-size: 1.02rem; letter-spacing: -.01em; white-space: nowrap; }
a.brand:hover { color: var(--brand-deep); }
a.brand img { border-radius: 7px; }
nav.site { display: flex; flex-wrap: wrap; gap: 4px 18px; margin-left: auto; }
nav.site a { color: var(--ink-soft); font-size: .93rem; padding: .35rem 0;
  border-bottom: 1px solid transparent; }
nav.site a:hover { color: var(--ink); border-bottom-color: var(--line-strong); }
nav.site a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--brand); }

/* 页头下面的状态条（2026-10-06）：说明"现在能装的是桌面版，插件还在开发"。
   整站共用（`_header.html` 里那一处），所以每页都能看到同一句话。 */
.notice { background: var(--brand-soft); border-bottom: 1px solid var(--line); }
.notice .wrap { padding-top: 9px; padding-bottom: 9px; }
.notice p { margin: 0; font-size: .87rem; color: var(--ink-soft); }
.notice strong { color: var(--ink); }
/* 汉堡菜单：checkbox 本身永远藏起来，label 只在窄屏出现（:checked ~ nav 展开）。没有 JS。 */
.nav-toggle-input { position: absolute; opacity: 0; width: 1px; height: 1px; pointer-events: none; }
label.nav-toggle { display: none; }
label.nav-toggle .bars, label.nav-toggle .bars::before, label.nav-toggle .bars::after {
  display: block; width: 16px; height: 1.5px; border-radius: 1px; background: currentColor; content: "";
}
label.nav-toggle .bars { position: relative; }
label.nav-toggle .bars::before { position: absolute; top: -5px; }
label.nav-toggle .bars::after { position: absolute; top: 5px; }
.nav-toggle-input:focus-visible + label.nav-toggle { outline: 2px solid var(--brand); outline-offset: 2px; }

/* ---------------------------------------------------------------- 按钮 ---------- */
.btn {
  display: inline-block; padding: .68rem 1.1rem; border-radius: var(--radius-sm);
  font-weight: 600; font-size: .95rem; line-height: 1.2; text-align: center;
  border: 1px solid transparent; cursor: pointer;
  transition: background .12s ease, border-color .12s ease, color .12s ease;
}
.btn.primary { background: var(--brand); color: #fff; }
.btn.primary:hover { background: var(--brand-deep); color: #fff; }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.btn.ghost:hover { border-color: var(--ink); color: var(--ink); }
.btn.small { padding: .46rem .85rem; font-size: .88rem; }
.btn.on-light { background: var(--brand-soft); color: var(--brand-deep); border-color: #d3ddf8; }
.btn.on-light:hover { background: #dde7ff; color: var(--brand-deep); }
.buttons { display: flex; flex-wrap: wrap; gap: .6rem; align-items: center; }

main { display: block; }
section { padding: clamp(2.4rem, 1.6rem + 2.6vw, 4.2rem) 0; }
section.alt { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
section.tight { padding: clamp(1.5rem, 1rem + 1.4vw, 2.4rem) 0; }

/* ---------------------------------------------------------------- 首页 hero ---------- */
/* 背景不是彩色渐变，而是一张"坐标纸"：极浅的 28px 方格，往下淡出。安静，而且一看就是科学工具。 */
.hero { position: relative; padding: clamp(2.4rem, 1.6rem + 3.2vw, 4.2rem) 0 clamp(1.8rem, 1.2rem + 2.4vw, 3.2rem);
  border-bottom: 1px solid var(--line);
  background-image:
    linear-gradient(to right, rgba(16, 22, 31, .05) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(16, 22, 31, .05) 1px, transparent 1px);
  background-size: 28px 28px;
}
.hero::after { content: ""; position: absolute; inset: 0; pointer-events: none;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0) 0%, rgba(255, 255, 255, .96) 72%, #fff 100%); }
.hero .wrap { position: relative; z-index: 1; display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(0, .98fr); gap: clamp(1.6rem, 1rem + 3vw, 3.4rem);
  align-items: center; }
.hero-copy { max-width: 41rem; }
.hero h1 { margin-bottom: .55em; }
.hero .lead { font-size: 1.07rem; color: var(--ink-soft); max-width: 35rem; }
.hero .buttons { margin-top: 1.5rem; }

/* 规格行：小字 + 字距 + 圆点分隔，替代上一版那四个彩色药丸。圆点跟在**句尾**（li:not(:last-child)::after）：
   用 li + li::before 的话，换行时圆点会跑到下一行的行首，读起来像漏了半句。 */
.badges { display: flex; flex-wrap: wrap; align-items: center; gap: .35rem 1.1rem; margin: 1.15rem 0 0;
  padding: 0; list-style: none; font-size: .84rem; color: var(--muted); }
.badges li { margin: 0; display: inline-flex; align-items: center; gap: .5rem; }
.badges li:not(:last-child)::after { content: ""; width: 3px; height: 3px; border-radius: 50%;
  background: var(--line-strong); }

/* 数字行：四列、上发丝线、衬线数字、tabular-nums。上一版是 flex，第四个会掉到下一行。 */
.hero-stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1rem 1.4rem;
  margin: 2.2rem 0 0; padding-top: 1.4rem; border-top: 1px solid var(--line); }
.hero-stats b { display: block; font-family: var(--serif); font-size: clamp(1.5rem, 1.2rem + .8vw, 1.85rem);
  color: var(--ink); line-height: 1.1; font-variant-numeric: tabular-nums; }
.hero-stats span { display: block; font-size: .82rem; color: var(--muted); margin-top: .15rem; }

/* 右侧"标本板"：四张真实图形，2×2 用发丝线分隔。没有阴影，没有旋转，没有浮动卡片。 */
.hero-art { display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden; background: #fff; }
.hero-art .shot-card { display: flex; align-items: center; justify-content: center;
  min-height: 158px; padding: 18px; }
.hero-art .shot-card + .shot-card { border-left: 1px solid var(--line); }
.hero-art .shot-card:nth-child(3) { border-left: 0; border-top: 1px solid var(--line); }
.hero-art .shot-card:nth-child(4) { border-top: 1px solid var(--line); }
.hero-art .shot-card img { max-height: 116px; width: auto; }

/* ---------------------------------------------------------------- 版块、卡片、标签 ---------- */
.lead { font-size: 1.07rem; color: var(--ink-soft); max-width: 62ch; }
.sub { color: var(--muted); font-size: .98rem; max-width: 68ch; }
.note { color: var(--muted); font-size: .87rem; }
.num { font-variant-numeric: tabular-nums; }

.grid { display: grid; gap: clamp(1rem, .6rem + 1.6vw, 1.5rem); }
.grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid.three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid.four { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* 卡片：1px 发丝线 + 10px 圆角，没有投影。上一版每张卡都带阴影，那是最"模板"的一处。 */
.card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 1.35rem 1.4rem; }
.card.plain { background: transparent; border-color: transparent; padding: 0; }
.card h3 { margin-bottom: .45em; }
.card p, .card li { font-size: .96rem; }
.card p:last-child, .card ul:last-child, .card ol:last-child { margin-bottom: 0; }
.card .note { margin-top: .6rem; }
.grid.two .card, .grid.three .card, .grid.four .card { height: 100%; }

/* 编号：发丝边框小方框里的等宽数字，替代上一版那块实心蓝方块 */
.icon-badge { display: inline-flex; align-items: center; justify-content: center; width: 26px; height: 26px;
  border: 1px solid var(--line-strong); border-radius: 4px; color: var(--ink);
  font: 700 .8rem/1 var(--mono); margin-bottom: .8rem; }

/* 小标签：发丝边 + 小号大写；.good/.warn 只用字色区分，不铺彩色底 */
.pill { display: inline-block; font-size: .72rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase;
  color: var(--muted); border: 1px solid var(--line-strong); border-radius: 4px; padding: .22rem .5rem;
  margin-bottom: .7rem; }
.pill.good { color: var(--good); border-color: #cfe3d8; }
.pill.warn { color: var(--warn); border-color: #eddfc4; }

.checks { list-style: none; padding: 0; }
.checks li { position: relative; padding-left: 1.45rem; font-size: .96rem; }
.checks li::before { content: ""; position: absolute; left: .12rem; top: .62em; width: .36rem; height: .36rem;
  border-radius: 50%; background: var(--brand); }

.steps { counter-reset: step; list-style: none; padding: 0; }
.steps > li { counter-increment: step; position: relative; padding-left: 3.1rem; }
.steps > li + li { margin-top: 1.1rem; }
.steps > li::before { content: counter(step); position: absolute; left: 0; top: .1rem;
  width: 2.05rem; height: 2.05rem; display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--line-strong); border-radius: 50%; color: var(--ink);
  font: 700 .9rem/1 var(--mono); font-variant-numeric: tabular-nums; }
.steps h3 { font-size: 1.05rem; margin-bottom: .3em; }

.callout { border: 1px solid var(--line); border-left: 3px solid var(--brand); border-radius: var(--radius-sm);
  background: var(--bg-soft); padding: .95rem 1.1rem; margin-bottom: 1rem; font-size: .96rem; }
.callout.warn { border-left-color: var(--warn); border-color: #efe3cf; background: #fdf8f0; }
.callout.good { border-left-color: var(--good); border-color: #d6e8dd; background: #f3f9f5; }
.callout p:last-child { margin-bottom: 0; }

/* 表格：发丝线、表头小号大写、数字右对齐且等宽。表头不再是一整条彩色带。 */
.table-scroll { overflow-x: auto; margin: 1.4rem 0; }
table { width: 100%; border-collapse: collapse; font-size: .95rem; }
caption { text-align: left; color: var(--muted); font-size: .86rem; padding-bottom: .6rem; }
th, td { text-align: left; padding: .68rem .8rem; border-bottom: 1px solid var(--line); vertical-align: top; }
thead th { font-size: .73rem; letter-spacing: .1em; text-transform: uppercase; color: var(--muted);
  font-weight: 700; border-bottom: 1px solid var(--line-strong); }
tbody td:not(:first-child) { font-variant-numeric: tabular-nums; }
tbody tr:hover { background: var(--bg-soft); }

.split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(1.4rem, 1rem + 2.5vw, 3rem); align-items: center; }
.split.reverse > :first-child { order: 2; }

/* 图库：每张图形一个小面板，图形居中、说明在下 - 像一本图册的排版 */
.figure-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(178px, 1fr)); gap: 1rem; }
.figure-grid figure { margin: 0; padding: 12px; border: 1px solid var(--line); border-radius: var(--radius-sm);
  background: #fff; }
.figure-grid figure img { display: block; height: 92px; width: auto; margin: 0 auto 10px; }
.figure-grid figcaption { font-size: .85rem; color: var(--ink); line-height: 1.35; }
.figure-grid .note { display: block; margin-top: .2rem; }

.breadcrumbs { font-size: .86rem; color: var(--muted); margin: 1.2rem 0 .4rem; }
.breadcrumbs ol { list-style: none; display: flex; flex-wrap: wrap; gap: .45rem; padding: 0; margin: 0; }
.breadcrumbs li + li::before { content: "/"; margin-right: .45rem; color: var(--line-strong); }

/* ---------------------------------------------------------------- 价格卡 ---------- */
.price-grid { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  gap: clamp(1.2rem, .8rem + 2vw, 2.4rem); align-items: start; }
.price-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 1.55rem 1.7rem; }
.price-card.featured { border-color: var(--line-strong); }
.price-card h2 { font-size: 1.32rem; }
.price { display: flex; align-items: baseline; gap: .6rem; margin: .2rem 0 1.1rem; }
.price b { font-family: var(--serif); font-size: 2.35rem; color: var(--ink); line-height: 1;
  font-variant-numeric: tabular-nums; }
.price span { color: var(--muted); font-size: .92rem; }
/* 价目行做成"规格表"：一行一项，左侧说明、右侧结论，中间发丝线 */
.price-rows { list-style: none; padding: 0; margin: 0 0 1.2rem; }
.price-rows li { display: flex; justify-content: space-between; gap: 1rem; padding: .5rem 0;
  border-bottom: 1px solid var(--line); font-size: .95rem; }
.price-rows li:first-child { border-top: 1px solid var(--line); }
.price-rows li > span { color: var(--muted); }
.price-rows b { font-weight: 650; color: var(--ink); white-space: nowrap; }

/* 横幅：纯品牌蓝（不再是 135° 渐变），字色统一 */
.band { background: var(--brand); color: #fff; border-radius: var(--radius);
  padding: clamp(1.5rem, 1.1rem + 1.8vw, 2.4rem); }
.band h2, .band h3 { color: #fff; }
.band p { color: rgba(255, 255, 255, .9); }
.band a { color: #fff; text-decoration: underline; text-decoration-color: rgba(255, 255, 255, .55); }
.band .btn.primary { background: #fff; color: var(--brand-deep); }
.band .btn.primary:hover { background: #eef3ff; color: var(--brand-deep); }
.band .btn.ghost { background: transparent; color: #fff; border-color: rgba(255, 255, 255, .5); }
.band .btn.ghost:hover { background: rgba(255, 255, 255, .1); border-color: #fff; color: #fff; }

/* 问答：发丝线卡片，展开不加阴影（阴影会让整页"跳"一下） */
details { border: 1px solid var(--line); border-radius: var(--radius-sm); background: #fff;
  padding: .9rem 1.05rem; margin-bottom: .55rem; }
summary { cursor: pointer; font-weight: 650; color: var(--ink); list-style: none;
  display: flex; gap: .6rem; align-items: flex-start; }
summary::-webkit-details-marker { display: none; }
summary::before { content: "+"; color: var(--muted); font-family: var(--mono); font-weight: 700; line-height: 1.35; }
details[open] summary::before { content: "\2013"; }
details > :not(summary) { margin-top: .7rem; }
details > :last-child { margin-bottom: 0; }

/* ---------------------------------------------------------------- 页脚 ---------- */
footer.site { background: #10161f; color: #b3bdc9; padding: clamp(2rem, 1.5rem + 2vw, 3rem) 0 1.5rem; }
footer.site .cols { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 2rem; }
footer.site h4 { color: #fff; font-size: .74rem; letter-spacing: .12em; text-transform: uppercase;
  margin-bottom: .9rem; }
footer.site p { font-size: .92rem; color: #97a3b1; }
footer.site ul { list-style: none; padding: 0; margin: 0; }
footer.site ul li { margin: .4rem 0; }
footer.site a { color: #cbd5e0; font-size: .92rem; }
footer.site a:hover { color: #fff; }
footer.site a.brand { color: #fff; margin-bottom: .7rem; }
footer.site .legal { border-top: 1px solid rgba(255, 255, 255, .12); margin-top: 2rem; padding-top: 1.1rem;
  font-size: .82rem; color: #8b97a5; }
footer.site .legal a { font-size: .82rem; }

/* ---------------------------------------------------------------- 工具类 ---------- */
.center { text-align: center; }
.center .sub, .center .lead { margin-left: auto; margin-right: auto; }
.center .buttons { justify-content: center; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }
.mt-2 { margin-top: 2rem; }

/* ---------------------------------------------------------------- 响应式 ---------- */
@media (max-width: 1000px) {
  .hero .wrap { grid-template-columns: minmax(0, 1fr); }
  .hero-art { max-width: 580px; margin-top: .4rem; }
  .grid.three, .grid.four { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .price-grid { grid-template-columns: minmax(0, 1fr); }
  .split { grid-template-columns: minmax(0, 1fr); }
  .split.reverse > :first-child { order: 0; }
  footer.site .cols { grid-template-columns: 1fr 1fr; }
  nav.site { gap: 2px 14px; }
}
@media (max-width: 760px) {
  /* 窄屏：导航收进汉堡菜单，触控目标一律 ≥44px，长词与长路径不许把版心撑破。 */
  header.site .wrap { flex-wrap: wrap; min-height: 0; padding-top: .55rem; padding-bottom: .55rem;
    gap: 10px 12px; }
  label.nav-toggle { display: inline-flex; align-items: center; gap: .55rem; margin-left: auto;
    padding: .55rem .9rem; min-height: 44px; border: 1px solid var(--line-strong); border-radius: var(--radius-sm);
    background: #fff; color: var(--ink); font-size: .95rem; font-weight: 600; cursor: pointer; }
  label.nav-toggle:hover { border-color: var(--ink); }
  nav.site { display: none; order: 4; width: 100%; margin: 0; padding: .2rem 0 .4rem;
    flex-direction: column; gap: 0; border-top: 1px solid var(--line); }
  .nav-toggle-input:checked ~ nav.site { display: flex; }
  nav.site a { padding: .85rem 2px; min-height: 44px; display: flex; align-items: center;
    font-size: 1.02rem; border-bottom: 1px solid var(--line); border-top: 0; }
  nav.site a:last-child { border-bottom: 0; }
  nav.site a[aria-current="page"] { border-bottom-color: var(--line); color: var(--ink); font-weight: 700; }
  a.brand { font-size: 1rem; }
  a.brand img { width: 30px; height: 30px; }
  .nav-buy { padding: .55rem .85rem; min-height: 44px; display: inline-flex; align-items: center; }
  section { padding: 2.1rem 0; }
  h1 { font-size: clamp(1.8rem, 1.2rem + 4.2vw, 2.5rem); }
  .hero { padding: 2rem 0 1.6rem; background-size: 24px 24px; }
  .hero-art { grid-template-columns: 1fr 1fr; }
  .hero-art .shot-card { min-height: 118px; padding: 12px; }
  .hero-art .shot-card img { max-height: 82px; }
  .hero-stats { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .9rem 1.2rem; }
  .btn { min-height: 44px; display: inline-flex; align-items: center; justify-content: center; }
  .card, .price-card { padding: 1.15rem 1.2rem; }
  .figure-grid { grid-template-columns: repeat(auto-fill, minmax(142px, 1fr)); gap: .8rem; }
  .figure-grid figure img { height: 74px; }
  .steps > li { padding-left: 2.7rem; }
  .steps > li::before { width: 1.9rem; height: 1.9rem; }
  .band { padding: 1.5rem 1.25rem; }
  footer.site .cols { grid-template-columns: 1fr; gap: 1.6rem; }
  .table-scroll { margin: 1.2rem -22px; padding: 0 22px; }
  table { font-size: .92rem; }
  th, td { padding: .6rem .65rem; }
}
@media (max-width: 680px) {
  body { font-size: 16px; }
  .grid.two, .grid.three, .grid.four { grid-template-columns: minmax(0, 1fr); }
  .grid.two.mt-2 { margin-top: 1.4rem; }
}
@media (max-width: 520px) {
  /* 极窄屏：把头部那个 Buy 按钮收起来（导航里就有 Licence，且每页都能看到价格） */
  .nav-buy { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

/* ---------------------------------------------------------------- 深色（跟随系统） ---------- */
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #eef1f5; --ink-soft: #c6cdd7; --muted: #94a0ae;
    --line: #242b35; --line-strong: #38424f;
    --bg: #0e1319; --bg-soft: #141a22; --bg-tint: #1a212b;
    --brand: #7aa5ff; --brand-deep: #a9c4ff; --brand-soft: #17233d;
    --accent: #e3a45f; --good: #7fd0a3; --warn: #e3b169;
    --shadow: 0 1px 0 rgba(0, 0, 0, .4);
    --shadow-lg: 0 10px 30px -16px rgba(0, 0, 0, .8);
  }
  header.site { background: rgba(14, 19, 25, .9); }
  /* 图形一律画在"白纸"上：导出的图形是白底线条图，放进深色格子会变成一块块白砖，
     所以标本板与图库的小面板在深色模式下仍然保持白底 - 像书里的图版。 */
  .hero { background-image:
    linear-gradient(to right, rgba(255, 255, 255, .05) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, .05) 1px, transparent 1px); }
  .hero::after { background: linear-gradient(180deg, rgba(14, 19, 25, 0) 0%,
    rgba(14, 19, 25, .96) 72%, #0e1319 100%); }
  .card, .price-card, details, table { background: #121820; }
  .btn.ghost, label.nav-toggle { background: #141a22; }
  tbody tr:hover { background: #161d26; }
  .callout { background: #141a22; }
  .callout.warn { background: #1f1a12; border-color: #3a2f1d; }
  .callout.good { background: #101d16; border-color: #1e3a2a; }
  .figure-grid figure { background: #fff; }
  .figure-grid figcaption, .figure-grid figcaption .note { color: #10161f; }
  footer.site { background: #0a0e13; }
}

@media print {
  header.site, footer.site, .btn, .breadcrumbs { display: none; }
  body { font-size: 11pt; color: #000; }
  .card, .price-card, table, details { box-shadow: none; }
  .hero { background: none; }
}

/* ---------------------------------------------------------------- 小修补（移动端踩出来的） ---------- */
/* 页内锚点不要顶到粘性页头下面（versions.html#classic 这类链接） */
:target, [id] { scroll-margin-top: 84px; }
/* 长路径、长邮箱、长 URL 不许把手机版心撑出横向滚动条 */
code, kbd, samp, a { overflow-wrap: anywhere; }
p, li, td, figcaption, h1, h2, h3 { overflow-wrap: break-word; }
@media (hover: none) { a:hover, .btn:hover { text-decoration: none; } }
html, body { max-width: 100%; }
.table-scroll, .figure-grid { max-width: 100%; }