/* ==========================================================================
   GIF 录制编辑器 · 官网样式
   结构：变量 → 基础 → 通用组件 → 导航 → Hero → 截图卡 → 各功能区块
        → 快捷键 → 下载 → FAQ → CTA → 页脚 → 响应式
   ========================================================================== */

/* ------------------------------------------------------------ 1. 变量 */

:root {
  --maxw: 1160px;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 7px;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Segoe UI",
          -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", sans-serif;
  --mono: ui-monospace, "Cascadia Mono", "SF Mono", Consolas, "Liberation Mono", monospace;
}

html[data-theme="dark"] {
  --bg: #080a10;
  --bg-alt: #0c0f17;
  --card: #12161f;
  --card-hi: #171d29;
  --line: rgba(255, 255, 255, .08);
  --line-hi: rgba(255, 255, 255, .17);
  --ink: #e9eef7;
  --ink-2: #b3bfd1;
  --muted: #7e8b9f;
  --brand: #4a83ff;
  --brand-2: #2f6bf0;
  --brand-soft: rgba(74, 131, 255, .13);
  --rec: #ff5257;
  --btn-face: #fff;
  --btn-face-ink: #1b2433;
  --shadow: 0 26px 70px rgba(0, 0, 0, .58);
  --shadow-sm: 0 10px 30px rgba(0, 0, 0, .38);
  --nav-bg: rgba(8, 10, 16, .74);
  --shot-bg: #0e121a;
  --demo-bg: #0b0e15;
  --glow: rgba(74, 131, 255, .17);
  --grid: rgba(255, 255, 255, .035);
}

html[data-theme="light"] {
  --bg: #ffffff;
  --bg-alt: #f5f7fb;
  --card: #ffffff;
  --card-hi: #f8fafd;
  --line: #e3e9f3;
  --line-hi: #cfd9e8;
  --ink: #101827;
  --ink-2: #33415c;
  --muted: #5f6f86;
  --brand: #2563eb;
  --brand-2: #1d4ed8;
  --brand-soft: rgba(37, 99, 235, .08);
  --rec: #e5484d;
  --btn-face: #2563eb;
  --btn-face-ink: #fff;
  --shadow: 0 22px 55px rgba(16, 30, 54, .14);
  --shadow-sm: 0 8px 24px rgba(16, 30, 54, .09);
  --nav-bg: rgba(255, 255, 255, .82);
  --shot-bg: #eef2f8;
  --demo-bg: #eef2f8;
  --glow: rgba(37, 99, 235, .10);
  --grid: rgba(16, 24, 39, .045);
}

/* ------------------------------------------------------------ 2. 基础 */

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4 { margin: 0; line-height: 1.24; font-weight: 800; letter-spacing: .01em; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
code { font-family: var(--mono); font-size: .92em; }

em {
  font-style: normal;
  background: linear-gradient(180deg, transparent 62%, var(--brand-soft) 62%);
  padding: 0 .08em;
  color: var(--brand);
}

::selection { background: var(--brand); color: #fff; }

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 200;
  background: var(--brand);
  color: #fff;
  padding: 9px 16px;
  border-radius: 0 0 8px 8px;
  transition: top .18s var(--ease);
}
.skip-link:focus { top: 0; }

/* ------------------------------------------------------------ 3. 通用组件 */

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 26px; }
.wrap-narrow { max-width: 830px; }

.section { padding: 96px 0; position: relative; }
.section-alt { background: var(--bg-alt); }

.sec-head { max-width: 660px; margin-bottom: 52px; }
.sec-head h2 { font-size: clamp(24px, 3.3vw, 35px); }
.sec-head p { margin-top: 14px; color: var(--muted); font-size: 15.5px; }
.sec-head.center { margin-left: auto; margin-right: auto; text-align: center; }

.sec-tag {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--brand);
  margin-bottom: 16px;
  text-transform: uppercase;
}
.sec-tag::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--brand);
  opacity: .6;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 13px 22px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  white-space: nowrap;
  transition: transform .14s var(--ease), background .18s var(--ease),
              border-color .18s var(--ease), box-shadow .18s var(--ease);
}
.btn:hover { transform: translateY(-1.5px); }
.btn:active { transform: translateY(0); }
.btn .i { width: 19px; height: 19px; flex: none; display: block; }

.btn-primary {
  background: var(--btn-face);
  color: var(--btn-face-ink);
  box-shadow: 0 10px 26px rgba(37, 99, 235, .26);
}
.btn-primary:hover { box-shadow: 0 14px 34px rgba(37, 99, 235, .34); }

.btn-ghost { border: 1px solid var(--line-hi); color: var(--ink); }
.btn-ghost:hover { background: var(--brand-soft); border-color: var(--brand); }

.btn-text { padding: 13px 4px; color: var(--ink-2); font-weight: 600; }
.btn-text:hover { color: var(--brand); }
.btn-text .i { width: 17px; height: 17px; transition: transform .18s var(--ease); }
.btn-text:hover .i { transform: translate(2px, -2px); }

.btn-sm { padding: 10px 17px; font-size: 14px; }

/* 进场动画 */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .62s var(--ease), transform .62s var(--ease);
  will-change: opacity, transform;
}
.reveal.in { opacity: 1; transform: none; }

/* 深浅色切换按钮的图标 */
html[data-theme="dark"] .i-sun { display: block; }
html[data-theme="dark"] .i-moon { display: none; }
html[data-theme="light"] .i-sun { display: none; }
html[data-theme="light"] .i-moon { display: block; }

/* ------------------------------------------------------------ 4. 导航 */

.nav {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--nav-bg);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.nav.stuck { border-bottom-color: var(--line); box-shadow: 0 6px 24px rgba(0, 0, 0, .16); }

.nav-inner { display: flex; align-items: center; gap: 16px; height: 64px; }

.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; }
.brand-logo { width: 32px; height: 32px; border-radius: 8px; }
.brand-text { font-size: 15.5px; letter-spacing: .01em; }
.brand-text b { font-weight: 800; color: var(--brand); }

.menu { display: flex; gap: 26px; margin-left: auto; font-size: 14.5px; color: var(--ink-2); }
.menu a { position: relative; transition: color .16s var(--ease); }
.menu a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -6px;
  height: 2px;
  background: var(--brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .22s var(--ease);
}
.menu a:hover { color: var(--ink); }
.menu a:hover::after { transform: scaleX(1); }

.nav-act { display: flex; align-items: center; gap: 10px; }

.icon-btn {
  width: 38px; height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-xs);
  border: 1px solid var(--line);
  color: var(--ink-2);
  transition: background .16s var(--ease), border-color .16s var(--ease), color .16s var(--ease);
}
.icon-btn:hover { background: var(--brand-soft); border-color: var(--brand); color: var(--brand); }
.icon-btn svg { width: 19px; height: 19px; stroke: currentColor; stroke-width: 1.8;
                fill: none; stroke-linecap: round; stroke-linejoin: round; }

.burger { display: none; flex-direction: column; gap: 4px; }
.burger span {
  display: block;
  width: 17px; height: 1.8px;
  background: currentColor;
  border-radius: 2px;
  transition: transform .22s var(--ease), opacity .18s var(--ease);
}
.burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(5.8px) rotate(45deg); }
.burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-5.8px) rotate(-45deg); }

/* ------------------------------------------------------------ 5. Hero */

.hero {
  position: relative;
  padding: 84px 0 108px;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: -30% -10% auto -10%;
  height: 780px;
  background:
    radial-gradient(560px 320px at 22% 12%, var(--glow), transparent 68%),
    radial-gradient(620px 300px at 82% 4%, rgba(255, 82, 87, .10), transparent 66%);
  pointer-events: none;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(760px 420px at 50% 0%, #000 8%, transparent 76%);
  mask-image: radial-gradient(760px 420px at 50% 0%, #000 8%, transparent 76%);
  pointer-events: none;
}
.hero .wrap { position: relative; z-index: 1; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 13px;
  color: var(--ink-2);
  background: var(--card);
  border: 1px solid var(--line-hi);
  border-radius: 999px;
  padding: 6px 15px;
  margin-bottom: 24px;
}
.eyebrow .dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--rec);
  box-shadow: 0 0 0 4px rgba(255, 82, 87, .16);
  animation: pulse 2.4s var(--ease) infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 4px rgba(255, 82, 87, .16); }
  50%      { box-shadow: 0 0 0 9px rgba(255, 82, 87, .04); }
}

.hero h1 {
  font-size: clamp(31px, 5.1vw, 55px);
  letter-spacing: -.015em;
  max-width: 17em;
}
.hero-desc {
  margin-top: 22px;
  font-size: clamp(15px, 1.5vw, 17px);
  color: var(--ink-2);
  max-width: 34em;
}
.hero-btns {
  display: flex;
  align-items: center;
  gap: 13px;
  flex-wrap: wrap;
  margin-top: 36px;
}
.hero-note {
  margin-top: 20px;
  font-size: 13px;
  color: var(--muted);
}
.hero-shot { margin-top: 62px; }

/* ------------------------------------------------------------ 6. 截图卡 */

.shot {
  border: 1px solid var(--line-hi);
  border-radius: var(--radius);
  background: var(--shot-bg);
  overflow: hidden;
  box-shadow: var(--shadow);
}
.browser-bar {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 11px 14px;
  background: var(--card);
  border-bottom: 1px solid var(--line);
}
.browser-bar i {
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--line-hi);
  flex: none;
}
.browser-bar i:nth-child(1) { background: #ff5f57; }
.browser-bar i:nth-child(2) { background: #febc2e; }
.browser-bar i:nth-child(3) { background: #28c840; }
.browser-url {
  margin-left: 10px;
  flex: 1;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  background: var(--bg-alt);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 3px 11px;
  text-align: center;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.shot-body { line-height: 0; }
.shot-body img { width: 100%; height: auto; }

/* ------------------------------------------------------------ 7. 录制方式（CSS 示意图） */

.rec-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }

.rec-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 22px 26px;
  transition: transform .18s var(--ease), border-color .18s var(--ease), box-shadow .18s var(--ease);
}
.rec-card:hover {
  transform: translateY(-3px);
  border-color: var(--line-hi);
  box-shadow: var(--shadow-sm);
}

/* 示意图画布：模拟一块桌面 */
.demo {
  position: relative;
  height: 168px;
  border-radius: var(--radius-sm);
  background: var(--demo-bg);
  border: 1px solid var(--line);
  overflow: hidden;
  margin-bottom: 20px;
}
.demo::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 22px 22px;
}

/* ① 区域框选：真正的 1px 红框 + 角把手 */
.demo-region {
  position: absolute;
  left: 34px; top: 40px;
  width: calc(100% - 78px);
  height: 92px;
  border: 1px solid var(--rec);
  box-shadow: 0 0 0 9999px rgba(8, 10, 16, .28);
}
.demo-region span {
  position: absolute;
  width: 7px; height: 7px;
  background: var(--rec);
  border-radius: 1.5px;
}
.demo-region span:nth-child(1) { left: -4px; top: -4px; }
.demo-region span:nth-child(2) { right: -4px; top: -4px; }
.demo-region span:nth-child(3) { left: -4px; bottom: -4px; }
.demo-region span:nth-child(4) { right: -4px; bottom: -4px; }
.demo-region span:nth-child(5) { left: calc(50% - 3.5px); top: -4px; width: 14px; height: 4px; }
.demo-region span:nth-child(6) { left: calc(50% - 3.5px); bottom: -4px; width: 14px; height: 4px; }
.demo-region span:nth-child(7) { left: -4px; top: calc(50% - 3.5px); width: 4px; height: 14px; }
.demo-region span:nth-child(8) { right: -4px; top: calc(50% - 3.5px); width: 4px; height: 14px; }
.demo-region b {
  position: absolute;
  left: 50%; bottom: -27px;
  transform: translateX(-50%);
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--rec);
  white-space: nowrap;
}

/* ② 窗口识别：高亮描边的窗口 */
.demo-win {
  position: absolute;
  left: 42px; top: 34px;
  width: calc(100% - 92px);
  height: 96px;
  border-radius: 8px;
  background: var(--card-hi);
  border: 1px solid var(--brand);
  box-shadow: 0 0 0 4px var(--brand-soft);
}
.demo-win i {
  position: absolute;
  left: 10px; top: 11px;
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--brand);
  opacity: .75;
}
.demo-win u {
  position: absolute;
  left: 25px; top: 12px;
  width: 46%; height: 7px;
  border-radius: 4px;
  background: var(--line-hi);
}
.demo-win em {
  position: absolute;
  left: 10px; top: 30px; right: 10px; bottom: 10px;
  border-radius: 5px;
  background: var(--brand-soft);
  border: 1px dashed var(--line-hi);
}
.demo-win b {
  position: absolute;
  right: -1px; top: -25px;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--brand);
  white-space: nowrap;
}

/* ③ 全屏 */
.demo-screen {
  position: absolute;
  left: 40px; right: 40px; top: 24px;
  height: 100px;
  border-radius: 8px;
  background: var(--card-hi);
  border: 1px solid var(--line-hi);
}
.demo-screen i {
  position: absolute;
  inset: 1px;
  border-radius: 7px;
  background: linear-gradient(135deg, var(--brand-soft), transparent 72%);
}
.demo-screen u {
  position: absolute;
  left: 50%; bottom: -22px;
  transform: translateX(-50%);
  width: 40px; height: 2px;
  background: var(--line-hi);
  border-radius: 2px;
}
.demo-screen em {
  position: absolute;
  left: 50%; top: 50%;
  transform: translate(-50%, -50%);
  width: 44px; height: 44px;
  border-radius: 50%;
  border: 2px solid var(--rec);
  display: flex;
  align-items: center;
  justify-content: center;
}
.demo-screen em::after {
  content: "";
  width: 15px; height: 15px;
  border-radius: 50%;
  background: var(--rec);
}
.demo-screen b {
  position: absolute;
  left: 50%; top: -24px;
  transform: translateX(-50%);
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--ink-2);
  white-space: nowrap;
}

.rec-card h3 { font-size: 17px; margin-bottom: 9px; }
.rec-card p { font-size: 14px; color: var(--muted); }

/* ------------------------------------------------------------ 8. 标注工具 */

.tool-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.tool-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 20px 18px;
  transition: transform .18s var(--ease), border-color .18s var(--ease), background .18s var(--ease);
}
.tool-card:hover { transform: translateY(-3px); border-color: var(--brand); background: var(--card-hi); }
.tool-ico {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px; height: 40px;
  border-radius: var(--radius-xs);
  background: var(--brand-soft);
  color: var(--brand);
  margin-bottom: 14px;
}
.tool-ico svg {
  width: 21px; height: 21px;
  stroke: currentColor; stroke-width: 1.75;
  fill: none; stroke-linecap: round; stroke-linejoin: round;
}
.tool-card h3 { font-size: 15px; margin-bottom: 6px; }
.tool-card p { font-size: 13px; color: var(--muted); }

/* ------------------------------------------------------------ 9. 时间轴示意 */

.tl {
  background: var(--card);
  border: 1px solid var(--line-hi);
  border-radius: var(--radius);
  padding: 20px 20px 24px;
  box-shadow: var(--shadow-sm);
  min-width: 0;   /* 允许作为 grid 子项被压缩，否则内容会撑开列宽 */
}
.tl-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  padding-bottom: 16px;
  margin-bottom: 18px;
  border-bottom: 1px solid var(--line);
}
.tl-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 12.5px;
  color: var(--ink-2);
  background: var(--bg-alt);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 13px;
}
.tl-btn.hot { background: var(--brand); border-color: var(--brand); color: #fff; font-weight: 600; }
.tl-btn .k {
  font-family: var(--mono);
  font-size: 10.5px;
  opacity: .7;
}
.tl-strip { display: flex; gap: 9px; overflow: hidden; padding: 4px 2px 12px; }
.tl-cell {
  position: relative;
  flex: none;
  width: 78px; height: 50px;
  border-radius: 7px;
  border: 1px solid var(--line);
  background:
    repeating-linear-gradient(45deg, var(--line) 0 1px, transparent 1px 7px),
    var(--bg-alt);
}
.tl-cell.cur {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px var(--brand-soft);
}
.tl-cell.cur::after {
  content: "当前帧";
  position: absolute;
  left: 50%; top: -9px;
  transform: translateX(-50%);
  background: var(--brand);
  color: #fff;
  font-size: 10px;
  line-height: 1;
  padding: 3px 7px;
  border-radius: 999px;
  white-space: nowrap;
}
.tl-cell.picked { border-color: var(--brand); background-color: var(--brand-soft); }
.tl-cell span {
  position: absolute;
  left: 5px; bottom: 5px;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--muted);
}
.tl-drop {
  position: absolute;
  width: 2px;
  top: 0; bottom: 0;
  left: -5px;
  background: var(--brand);
  border-radius: 2px;
}
.tl-drop::before {
  content: "";
  position: absolute;
  left: -3px; top: -4px;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--brand);
}
.tl-foot {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  margin-top: 6px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--muted);
}
.tl-foot b { color: var(--ink-2); font-weight: 600; }

.split {
  display: grid;
  /* 注意：这里必须写 minmax(0, 1fr) 而不是 1fr。
     1fr 等价于 minmax(auto, 1fr)，auto 会取"内容最小宽度"，
     时间轴那排缩略图会把列撑到 500+px，把整个页面顶出横向滚动条。 */
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.25fr);
  gap: 52px;
  align-items: center;
}
.split.rev { grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); }
.split .sec-head { margin-bottom: 0; }
.split-list { margin-top: 24px; display: grid; gap: 12px; }
.split-list li {
  position: relative;
  padding-left: 26px;
  font-size: 14.5px;
  color: var(--muted);
}
.split-list li::before {
  content: "";
  position: absolute;
  left: 5px; top: .62em;
  width: 7px; height: 7px;
  border-radius: 2px;
  background: var(--brand);
}
.split-list b { color: var(--ink); font-weight: 600; }

/* ------------------------------------------------------------ 10. 更多功能 */

.feat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.feat-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 22px;
  transition: transform .18s var(--ease), border-color .18s var(--ease), box-shadow .18s var(--ease);
}
.feat-card:hover {
  transform: translateY(-3px);
  border-color: var(--line-hi);
  box-shadow: var(--shadow-sm);
}
.feat-ico {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px; height: 42px;
  border-radius: 11px;
  background: var(--brand-soft);
  color: var(--brand);
  margin-bottom: 16px;
}
.feat-ico svg {
  width: 22px; height: 22px;
  stroke: currentColor; stroke-width: 1.7;
  fill: none; stroke-linecap: round; stroke-linejoin: round;
}
.feat-card h3 { font-size: 16px; margin-bottom: 8px; }
.feat-card p { font-size: 13.5px; color: var(--muted); }

/* ------------------------------------------------------------ 11. 快捷键 */

.keys { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.key-box {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 8px 24px 20px;
}
.key-box h3 {
  font-size: 14px;
  letter-spacing: .04em;
  color: var(--brand);
  padding: 18px 0 14px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 6px;
}
.key-row {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--line);
  font-size: 14px;
}
.key-row:last-child { border-bottom: 0; }
.key-row > span { color: var(--muted); }
.kbd {
  flex: none;
  min-width: 152px;
  display: flex;
  align-items: center;
  gap: 5px;
  flex-wrap: wrap;
}
kbd {
  font-family: var(--mono);
  font-size: 11.5px;
  line-height: 1;
  padding: 5px 8px;
  border-radius: 5px;
  background: var(--bg-alt);
  border: 1px solid var(--line-hi);
  border-bottom-width: 2px;
  color: var(--ink-2);
  white-space: nowrap;
}
kbd.hi { background: var(--brand-soft); border-color: var(--brand); color: var(--brand); }

/* ------------------------------------------------------------ 12. 下载 */

.dl-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.dl-card {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px;
  transition: transform .18s var(--ease), border-color .18s var(--ease), box-shadow .18s var(--ease);
}
a.dl-card:hover, .dl-card:hover {
  transform: translateY(-3px);
  border-color: var(--brand);
  box-shadow: var(--shadow-sm);
}
.dl-card.is-main { border-color: var(--brand); box-shadow: 0 0 0 1px var(--brand) inset; }
.dl-ico {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px; height: 46px;
  border-radius: 12px;
  background: var(--brand-soft);
  color: var(--brand);
  margin-bottom: 13px;
}
.dl-ico svg {
  width: 23px; height: 23px;
  stroke: currentColor; stroke-width: 1.7;
  fill: none; stroke-linecap: round; stroke-linejoin: round;
}
.dl-card b { font-size: 16.5px; }
.dl-sub { font-size: 13px; color: var(--muted); }
.dl-links { display: flex; gap: 16px; flex-wrap: wrap; margin-top: 13px; }
.dl-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--brand);
}
.dl-link:hover { text-decoration: underline; }
.dl-link svg {
  width: 15px; height: 15px;
  stroke: currentColor; stroke-width: 1.8;
  fill: none; stroke-linecap: round; stroke-linejoin: round;
}
.dl-tip {
  margin-top: 26px;
  font-size: 13.5px;
  color: var(--muted);
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-xs);
  padding: 15px 20px;
}
.dl-tip code {
  background: var(--bg-alt);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1px 6px;
  color: var(--ink-2);
}
/* 卡片底部的补充说明：灰色，避免和可点的 .dl-link 混淆 */
.dl-note {
  display: block;
  margin-top: 13px;
  font-size: 12.5px;
  color: var(--muted);
}

/* ------------------------------------------------------------ 13. FAQ */

.faq { display: grid; gap: 12px; }
.faq details {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0 22px;
  transition: border-color .18s var(--ease);
}
.faq details[open] { border-color: var(--line-hi); }
.faq summary {
  cursor: pointer;
  list-style: none;
  font-weight: 600;
  font-size: 15.5px;
  padding: 18px 30px 18px 0;
  position: relative;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "";
  position: absolute;
  right: 2px; top: 50%;
  width: 9px; height: 9px;
  border-right: 1.8px solid var(--muted);
  border-bottom: 1.8px solid var(--muted);
  transform: translateY(-70%) rotate(45deg);
  transition: transform .2s var(--ease);
}
.faq details[open] summary::after { transform: translateY(-30%) rotate(-135deg); }
.faq details p {
  font-size: 14px;
  color: var(--muted);
  padding: 0 0 19px;
  margin-top: -4px;
  max-width: 68ch;
}

/* ------------------------------------------------------------ 14. CTA */

.cta {
  text-align: center;
  background:
    radial-gradient(520px 260px at 50% 0%, var(--glow), transparent 70%),
    var(--bg-alt);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.cta .sec-head { max-width: 640px; }
.cta .hero-btns { justify-content: center; }
.cta h2 { font-size: clamp(25px, 3.6vw, 38px); }

/* ------------------------------------------------------------ 15. 页脚 */

.footer { padding: 68px 0 30px; }
.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.3fr;
  gap: 40px;
  padding-bottom: 44px;
  border-bottom: 1px solid var(--line);
}
.footer-brand p {
  margin-top: 14px;
  font-size: 13.5px;
  color: var(--muted);
  max-width: 26em;
}
.footer-col h4 {
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--muted);
  font-weight: 600;
  margin-bottom: 16px;
  text-transform: uppercase;
}
.footer-col a, .footer-col span {
  display: block;
  font-size: 14px;
  color: var(--ink-2);
  margin-bottom: 11px;
  transition: color .16s var(--ease);
}
.footer-col a:hover { color: var(--brand); }
.footer-col span { color: var(--muted); font-size: 13px; }
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 22px;
  font-size: 13px;
  color: var(--muted);
}
.footer-bottom a:hover { color: var(--brand); }

/* ------------------------------------------------------------ 16. 响应式 */

@media (max-width: 1080px) {
  .tool-grid { grid-template-columns: repeat(2, 1fr); }
  .feat-grid { grid-template-columns: repeat(2, 1fr); }
  .split, .split.rev { grid-template-columns: minmax(0, 1fr); gap: 36px; }
  .split.rev .tl { order: 2; }
}

@media (max-width: 900px) {
  .menu {
    position: fixed;
    left: 0; right: 0; top: 64px;
    flex-direction: column;
    gap: 0;
    margin: 0;
    background: var(--card);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-sm);
    padding: 8px 26px 18px;
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: opacity .2s var(--ease), transform .2s var(--ease), visibility .2s;
  }
  .menu.open { opacity: 1; visibility: visible; transform: none; }
  .menu a { padding: 13px 0; border-bottom: 1px solid var(--line); }
  .menu a:last-child { border-bottom: 0; }
  .menu a::after { display: none; }
  .burger { display: inline-flex; }
  .nav-act .btn-sm { display: none; }
  .rec-grid { grid-template-columns: 1fr; gap: 18px; }
  .dl-grid { grid-template-columns: 1fr; }
  .keys { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  body { font-size: 15px; }
  .wrap { padding: 0 18px; }
  .section { padding: 66px 0; }
  .hero { padding: 56px 0 76px; }
  .hero-shot { margin-top: 42px; }
  .hero-btns { gap: 10px; }
  .hero-btns .btn { flex: 1 1 auto; }
  .hero-btns .btn-text { flex: 1 1 100%; justify-content: flex-start; }
  .tool-grid { grid-template-columns: 1fr; }
  .feat-grid { grid-template-columns: 1fr; }
  .sec-head { margin-bottom: 36px; }
  .kbd { min-width: 0; width: 100%; }
  .key-row { flex-direction: column; align-items: flex-start; gap: 7px; }
  .tl-strip { overflow-x: auto; }
  .tl-cell { width: 66px; height: 44px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}

/* 打印：去掉装饰，保留内容 */
@media print {
  .nav, .hero::before, .hero::after, .cta, .tl-bar { display: none; }
  .reveal { opacity: 1; transform: none; }
  body { color: #000; background: #fff; }
}