/* ============ Reset & Tokens ============ */
* { margin:0; padding:0; box-sizing:border-box; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}
:root {
  --bg: #141413;
  --bg-2: #1c1c1a;
  --surface: #222220;
  --surface-2: #2a2a27;
  --border: rgba(255,255,255,0.08);
  --border-strong: rgba(255,255,255,0.14);
  --text: #faf9f5;
  --text-2: #b0aea5;
  --text-3: #6b6963;
  /* changelog 徽章/日期/页脚使用的弱化色（此前未定义导致 var() 失效降级） */
  --text-muted: #6b6963;
  --text-secondary: #b0aea5;
  --mode-text: #d97757;
  --mode-image: #6a9bcc;
  --accent: #3b82f6;
  --accent-hover: #60a5fa;
  --accent-2: #d97757;
  --accent-3: #788c5d;
  --font: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Lora', Georgia, 'Times New Roman', serif;
  --mono: 'SF Mono', 'Fira Code', ui-monospace, Consolas, monospace;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

html { scroll-behavior:smooth; }
body {
  font-family:var(--font-body);
  background:
    radial-gradient(circle at 18% 12%, rgba(59,130,246,0.2), transparent 30%),
    radial-gradient(circle at 82% 4%, rgba(217,119,87,0.13), transparent 28%),
    linear-gradient(180deg, #171716 0%, var(--bg) 42%, #10100f 100%);
  color:var(--text);
  line-height:1.6;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
body::before {
  content:'';
  position:fixed;
  inset:0;
  z-index:-1;
  pointer-events:none;
  background:
    linear-gradient(90deg, rgba(20,20,19,0.8) 0%, rgba(20,20,19,0.5) 42%, rgba(20,20,19,0.72) 100%),
    linear-gradient(180deg, rgba(20,20,19,0.26) 0%, rgba(20,20,19,0.78) 78%, var(--bg) 100%);
}

/* ============ 流动背景 ============ */
#flowBg {
  position:fixed; inset:0; z-index:-2; pointer-events:none;
  width:100%; height:100%;
  opacity:0.72;
  mix-blend-mode:screen;
}
a { color:inherit; text-decoration:none; }
h1, h2, h3, h4, h5, h6 { font-family:var(--font); }

/* ============ 通用 ============ */
section { position:relative; }
.section-title {
  font-size:clamp(26px, 3.4vw, 40px); font-weight:700; text-align:center;
  letter-spacing:-0.5px; margin-bottom:48px; line-height:1.2;
  color:var(--text);
}

/* ============ 按钮 ============ */
.btn {
  display:inline-flex; align-items:center; gap:9px; justify-content:center;
  font-weight:600; border-radius:10px; cursor:pointer; border:none;
  font-family:var(--font); transition:all .2s var(--ease);
  position:relative; white-space:nowrap;
}
.btn-sm { padding:9px 18px; font-size:13.5px; }
.btn-lg { padding:14px 28px; font-size:15.5px; }
.btn-chrome {
  background:var(--accent); color:#fff;
  box-shadow:0 1px 3px rgba(0,0,0,0.2);
}
.btn-chrome:hover { background:var(--accent-hover); transform:translateY(-1px); box-shadow:0 4px 16px rgba(217,119,87,0.25); }
.btn-chrome:active { transform:translateY(0); box-shadow:0 1px 2px rgba(0,0,0,0.15); }
.btn-ghost { background:var(--surface); color:var(--text); border:1px solid var(--border); }
.btn-ghost:hover { background:var(--surface-2); border-color:var(--border-strong); transform:translateY(-1px); }
.demo-wrap:focus { outline: 2px solid var(--accent); outline-offset: 4px; }

/* ============ 导航栏 ============ */
.nav { position:fixed; top:0; left:0; right:0; z-index:100; transition:background .3s var(--ease), border-color .3s var(--ease), box-shadow .3s var(--ease); border-bottom:1px solid transparent; }
.nav.scrolled { background:rgba(20,20,19,0.88); border-bottom-color:var(--border); box-shadow:0 1px 8px rgba(0,0,0,0.2); }
.nav-inner { max-width:1180px; margin:0 auto; padding:14px 28px; display:flex; align-items:center; gap:24px; }
.brand { display:flex; align-items:center; gap:10px; font-weight:700; font-size:19px; font-family:var(--font); }
.brand-logo { width:30px; height:30px; }
.brand-it { color:var(--accent); }
.nav-links { display:flex; gap:28px; margin-left:auto; font-size:14.5px; color:var(--text-2); font-family:var(--font); }
.nav-links a { position:relative; transition:color .2s; }
.nav-links a::after { content:''; position:absolute; left:0; bottom:-5px; width:0; height:2px; background:var(--accent); border-radius:2px; transition:width .25s var(--ease); }
.nav-links a:hover { color:var(--text); }
.nav-links a:hover::after { width:100%; }
.nav-menu-toggle {
  display:none; width:44px; height:44px; border-radius:10px;
  border:1px solid var(--border); background:var(--surface);
  color:var(--text); align-items:center; justify-content:center;
  flex-direction:column; gap:5px; cursor:pointer;
}
.nav-menu-toggle span {
  width:18px; height:2px; border-radius:2px; background:currentColor;
}

/* ============ HERO ============ */
.hero {
  max-width:1180px; margin:0 auto; padding:70px 28px 80px;
  min-height:100vh; min-height:100dvh;
  display:grid; grid-template-columns:1fr 1.05fr; gap:54px; align-items:center;
}
.eyebrow {
  display:inline-flex; align-items:center; gap:8px; font-size:13px; font-weight:600;
  color:var(--text-2); background:var(--surface); border:1px solid var(--border);
  padding:6px 14px; border-radius:999px; margin-bottom:22px;
  font-family:var(--font);
}
.dot-live { width:8px; height:8px; border-radius:50%; background:var(--accent-3); box-shadow:0 0 0 0 rgba(120,140,93,0.4); animation:livePulse 1.8s infinite; }
@keyframes livePulse { 0%{box-shadow:0 0 0 0 rgba(120,140,93,0.4);} 70%{box-shadow:0 0 0 8px rgba(120,140,93,0);} 100%{box-shadow:0 0 0 0 rgba(120,140,93,0);} }
.hero-title { font-size:clamp(34px, 4.6vw, 56px); font-weight:700; letter-spacing:-1px; line-height:1.1; color:var(--text); }
.hero-title .hl { color:var(--accent); }
.hero-sub { margin-top:20px; font-size:clamp(15px,1.5vw,18px); color:var(--text-2); line-height:1.7; }
.hero-sub b { color:var(--text); font-weight:700; }
.hero-cta { margin-top:32px; display:flex; gap:14px; flex-wrap:wrap; }
.hero-trust { margin-top:24px; font-size:13.5px; color:var(--text-3); font-family:var(--font); }
.hero-trust b { color:var(--text-2); }

/* ============ DEMO 浏览器 ============ */
.demo-wrap { position:relative; }
.browser {
  background:var(--surface); border-radius:14px; overflow:hidden;
  box-shadow:0 4px 24px rgba(0,0,0,0.3), 0 0 0 1px var(--border);
}
.browser-bar { height:38px; background:#1a1a18; display:flex; align-items:center; gap:7px; padding:0 14px; border-bottom:1px solid var(--border); }
.tdot { width:11px; height:11px; border-radius:50%; }
.tdot.r{background:#ff5f57;}.tdot.y{background:#febc2e;}.tdot.g{background:#28c840;}
.browser-url { margin-left:8px; flex:1; max-width:280px; height:22px; background:rgba(255,255,255,0.06); border:1px solid var(--border); border-radius:6px; display:flex; align-items:center; gap:6px; padding:0 10px; font-size:11px; color:var(--text-3); font-family:var(--font); }
.browser-body { position:relative; height:430px; overflow:hidden; background:#f6f3ec; }

/* 模拟网页 */
.mock-page { padding:0; font-size:13px; color:#2a2a35; height:100%; }
.mp-nav { display:flex; align-items:center; justify-content:space-between; padding:14px 22px; border-bottom:1px solid #ddd6c9; background:#fffaf1; }
.mp-logo { font-weight:700; font-size:15px; color:#24211c; font-family:var(--font); }
.mp-links { display:flex; gap:18px; font-size:12.5px; color:#7d7569; font-family:var(--font); }
.mp-cta { background:#24211c; color:#fffaf1; border:none; padding:7px 16px; border-radius:8px; font-size:12.5px; font-weight:600; cursor:default; font-family:var(--font); }
.mp-hero { text-align:left; padding:26px 24px 18px; }
.mp-kicker { display:inline-flex; align-items:center; padding:4px 9px; border-radius:999px; background:#e9f2ff; color:#2f6eb8; font-size:10.5px; font-weight:700; letter-spacing:0.02em; font-family:var(--font); }
.mp-hero h2 { margin-top:12px; font-size:27px; font-weight:700; color:#24211c; line-height:1.16; font-family:var(--font); }
.mp-hero p { margin:10px 0 16px; font-size:12.5px; color:#756d62; max-width:330px; line-height:1.65; }
.mp-primary { background:var(--accent); color:#fff; border:none; padding:10px 22px; border-radius:9px; font-size:13px; font-weight:600; cursor:default; font-family:var(--font); box-shadow:0 7px 18px rgba(59,130,246,0.2); }
.mp-cards { display:flex; gap:12px; padding:8px 22px 22px; }
.mp-card { flex:1; min-width:0; padding:15px 14px; background:#fffaf1; border:1px solid #ddd6c9; border-radius:11px; }
.mp-ic { width:28px; height:28px; display:flex; align-items:center; justify-content:center; border-radius:9px; background:#eef4ff; color:#2f6eb8; font-size:13px; font-weight:700; margin-bottom:8px; font-family:var(--font); }
.mp-card h3 { font-size:12.5px; color:#24211c; margin-bottom:4px; font-family:var(--font); }
.mp-card p { font-size:10.5px; color:#7d7569; line-height:1.45; }

/* 可点击元素的 hover 提示（标注模式下） */
.browser.annotating .mock-page [data-el]:hover { cursor:crosshair; outline:2px dashed rgba(217,119,87,0.5); outline-offset:2px; border-radius:4px; }
.browser.annotating.mode-image .mock-page [data-el]:hover { outline-color:rgba(106,155,204,0.6); }

/* 标注层 */
.anno-layer { position:absolute; inset:0; pointer-events:none; z-index:20; }
.anno-hl {
  position:absolute; border:2px solid var(--mode-text); background:rgba(217,119,87,0.08);
  border-radius:5px; animation:hlIn .35s cubic-bezier(0.34,1.56,0.64,1);
}
.anno-hl.image {
  border:2px dashed var(--mode-image); background:rgba(106,155,204,0.06);
  border-radius:10px;
}
@keyframes hlIn { from{opacity:0; transform:scale(0.92);} to{opacity:1; transform:scale(1);} }
.anno-pin {
  position:absolute; width:26px; height:26px; border-radius:50%; color:#fff;
  font-weight:700; font-size:12px; display:flex; align-items:center; justify-content:center;
  border:2px solid #fff; transform:translate(-50%,-50%); z-index:25;
  cursor:pointer; pointer-events:auto;
  animation:pinDrop .45s cubic-bezier(0.34,1.56,0.64,1);
  transition:transform .25s cubic-bezier(0.34,1.56,0.64,1);
  font-family:var(--font);
}
.anno-pin:hover { transform:translate(-50%,-50%) scale(1.15); }
.anno-pin.text { background:var(--mode-text); box-shadow:0 2px 8px rgba(217,119,87,0.4); }
.anno-pin.image { background:var(--mode-image); box-shadow:0 2px 8px rgba(106,155,204,0.4); }
.anno-pin-pulse { position:absolute; inset:0; border-radius:50%; background:inherit; animation:pinPing 1.5s cubic-bezier(0,0,0.2,1) infinite; opacity:0.6; z-index:-1; }
@keyframes pinDrop { from{opacity:0; transform:translate(-50%,-50%) scale(0) translateY(-8px);} to{opacity:1; transform:translate(-50%,-50%) scale(1);} }
@keyframes pinPing { 0%{transform:scale(1); opacity:.6;} 75%,100%{transform:scale(2); opacity:0;} }

/* 原型模式标签卡片 */
.anno-label {
  position:absolute; color:var(--text); padding:14px 16px;
  border-radius:10px; min-width:220px; max-width:280px;
  background:var(--surface);
  box-shadow:0 4px 16px rgba(0,0,0,0.25), 0 0 0 1px var(--border);
  border-left:4px solid var(--mode-image);
  pointer-events:auto; z-index:26;
  animation:labelIn .4s cubic-bezier(0.34,1.56,0.64,1);
  font-family:var(--font);
}
@keyframes labelIn { from{opacity:0; transform:translateX(-12px) scale(0.95);} to{opacity:1; transform:translateX(0) scale(1);} }
.anno-label-title { font-weight:600; font-size:13.5px; color:var(--text); }
.anno-label-desc { font-size:12px; color:var(--text-2); margin-top:5px; line-height:1.55; }
.anno-label-close {
  position:absolute; top:8px; right:8px; width:20px; height:20px;
  border-radius:50%; border:1px solid var(--border);
  background:var(--bg-2); color:var(--text-3);
  display:flex; align-items:center; justify-content:center;
  cursor:pointer; font-size:11px; opacity:0;
  transition:all .2s;
}
.anno-label:hover .anno-label-close { opacity:1; }
.anno-label-close:hover { background:var(--border); color:var(--text); }

/* SVG 贝塞尔连线 */
.anno-lines { position:absolute; inset:0; pointer-events:none; z-index:24; overflow:visible; }

/* 拖拽框选 */
.anno-drag-box {
  position:absolute; pointer-events:none; z-index:21;
  border:2px dashed rgba(217,119,87,0.5); background:rgba(217,119,87,0.06);
  border-radius:6px; display:none;
}
.browser.mode-image .anno-drag-box {
  border-color:rgba(106,155,204,0.5); background:rgba(106,155,204,0.06);
}

/* Pin 点击弹出详情 */
.anno-popover {
  position:absolute; width:260px;
  background:var(--surface); border-radius:12px;
  box-shadow:0 8px 30px rgba(0,0,0,0.35), 0 0 0 1px var(--border);
  border:1px solid var(--border);
  pointer-events:auto; z-index:28; overflow:hidden;
  font-family:var(--font);
  animation:popoverIn .35s cubic-bezier(0.34,1.56,0.64,1);
}
@keyframes popoverIn { from{opacity:0; transform:translateY(8px) scale(0.96);} to{opacity:1; transform:translateY(0) scale(1);} }
.anno-popover-head {
  padding:10px 14px; display:flex; align-items:center; justify-content:space-between;
  border-bottom:1px solid var(--border);
}
.anno-popover-tag { display:flex; align-items:center; gap:7px; font-size:12.5px; color:var(--text-2); font-weight:600; }
.anno-popover-tag .idx { width:20px; height:20px; border-radius:50%; display:flex; align-items:center; justify-content:center; font-size:10px; font-weight:700; color:#fff; border:1.5px solid #fff; }
.anno-popover-tag .idx.text { background:var(--mode-text); }
.anno-popover-tag .idx.image { background:var(--mode-image); }
.anno-popover-close {
  width:22px; height:22px; border-radius:6px; border:1px solid var(--border);
  background:var(--bg-2); color:var(--text-3);
  display:flex; align-items:center; justify-content:center; cursor:pointer;
  font-size:13px; transition:all .15s;
}
.anno-popover-close:hover { background:var(--border); color:var(--text); }
.anno-popover-body { padding:10px 14px; font-size:12px; color:var(--text-2); line-height:1.65; }
.anno-popover-body .field { display:flex; gap:6px; margin-bottom:5px; }
.anno-popover-body .field-label { color:var(--text-3); font-weight:600; min-width:50px; }
.anno-popover-body .field-value { color:var(--text-2); font-family:var(--mono); font-size:11px; }
.anno-popover-body .feedback-text { color:var(--text); margin-top:6px; padding-top:6px; border-top:1px solid var(--border); font-size:12.5px; }
.anno-popover-foot {
  padding:8px 14px; display:flex; align-items:center; justify-content:flex-end; gap:6px;
  border-top:1px solid var(--border);
}
.anno-popover-btn {
  padding:5px 11px; font-size:11.5px; font-weight:600; border:none;
  border-radius:7px; cursor:pointer; display:flex; align-items:center; gap:4px;
  transition:all .15s; font-family:var(--font);
}
.anno-popover-btn.copy { background:var(--bg-2); color:var(--text-2); border:1px solid var(--border); }
.anno-popover-btn.copy:hover { background:var(--border); color:var(--text); }
.anno-popover-btn.copy.done { background:var(--accent-3); color:#fff; border-color:transparent; }
.anno-popover-btn.del { background:rgba(217,119,87,0.08); color:var(--mode-text); border:1px solid rgba(217,119,87,0.15); }
.anno-popover-btn.del:hover { background:rgba(217,119,87,0.15); }

/* 工具栏 */
.mk-toolbar {
  position:absolute; right:18px; bottom:18px; z-index:30;
  background:var(--surface); border-radius:999px; padding:4px;
  display:flex; flex-direction:column; align-items:center; gap:3px;
  box-shadow:0 4px 16px rgba(0,0,0,0.25), 0 0 0 1px var(--border);
  border:1px solid var(--border);
}
.mk-modes { background:var(--bg-2); border-radius:999px; padding:3px; display:flex; flex-direction:column; gap:3px; border:1px solid var(--border); }
.mk-mode { width:44px; height:44px; min-width:44px; min-height:44px; border-radius:50%; border:none; background:transparent; color:var(--text-3); display:flex; align-items:center; justify-content:center; cursor:pointer; transition:all .25s cubic-bezier(0.34,1.56,0.64,1); }
.mk-mode:hover { background:var(--border); }
.mk-mode.active[data-mode="text"] { background:var(--mode-text); color:#fff; box-shadow:0 2px 8px rgba(217,119,87,0.35); }
.mk-mode.active[data-mode="image"] { background:var(--mode-image); color:#fff; box-shadow:0 2px 8px rgba(106,155,204,0.35); }
.mk-mode-tooltip {
  position:absolute; right:calc(100% + 8px); top:50%; transform:translateY(-50%);
  background:#3a3a37; color:var(--text); font-size:11px; font-weight:600;
  padding:5px 10px; border-radius:6px; white-space:nowrap; pointer-events:none;
  opacity:0; transition:opacity 0.2s, transform 0.2s cubic-bezier(0.34,1.56,0.64,1);
  box-shadow:0 2px 8px rgba(0,0,0,0.12);
  transform:translateY(-50%) translateX(4px);
}
.mk-mode:hover .mk-mode-tooltip { opacity:1; transform:translateY(-50%) translateX(0); }
.mk-sep { width:22px; height:1px; background:var(--border); margin:1px 0; }
.mk-tool { width:44px; height:44px; min-width:44px; min-height:44px; border-radius:50%; border:none; background:transparent; color:var(--text-3); display:flex; align-items:center; justify-content:center; cursor:pointer; transition:all .2s; }
.mk-tool:hover { background:var(--bg-2); color:var(--mode-text); }
.mk-tool.hidden-state { color:var(--border); }
.mk-tool.confirm { color:var(--mode-text); background:rgba(217,119,87,0.1); animation:confirmPulse 0.6s ease; }
@keyframes confirmPulse { 0%,100%{transform:scale(1);} 50%{transform:scale(1.15);} }
.mk-trigger {
  width:40px; height:40px; border-radius:50%; background:var(--mode-text); display:flex; align-items:center; justify-content:center;
  box-shadow:0 2px 8px rgba(217,119,87,0.35);
  border:2px solid rgba(255,255,255,0.3); color:#fff;
  transition:background .3s var(--ease), transform .3s cubic-bezier(0.34,1.56,0.64,1), box-shadow .3s var(--ease);
}
.mk-trigger:hover { transform:scale(1.08); }
.mk-trigger.active { box-shadow:0 2px 8px rgba(217,119,87,0.35), 0 0 0 3px rgba(217,119,87,0.2); }
.mk-toolbar.mode-image .mk-trigger { background:var(--mode-image); box-shadow:0 2px 8px rgba(106,155,204,0.35); }
.mk-toolbar.mode-image .mk-trigger.active { box-shadow:0 2px 8px rgba(106,155,204,0.35), 0 0 0 3px rgba(106,155,204,0.2); }

/* 快捷键提示 */
.demo-shortcut-hint {
  text-align:center; margin-top:16px; font-size:12px; color:var(--text-3);
  display:flex; align-items:center; justify-content:center; gap:4px;
  font-family:var(--font);
}
.demo-shortcut-hint kbd {
  display:inline-flex; align-items:center; justify-content:center;
  min-width:22px; height:22px; padding:0 5px;
  background:var(--surface); border:1px solid var(--border);
  border-radius:5px; font-family:var(--mono); font-size:11px; color:var(--text-2);
  box-shadow:0 1px 2px rgba(0,0,0,0.15);
}
.demo-shortcut-hint span { margin-left:4px; }

/* 输出面板 */
.output-panel {
  margin-top:18px; background:var(--surface); border-radius:14px;
  border:1px solid var(--border); overflow:hidden;
  box-shadow:0 4px 16px rgba(0,0,0,0.2);
}
.op-head { display:flex; align-items:center; justify-content:space-between; padding:11px 16px; border-bottom:1px solid var(--border); }
.op-title { font-size:12.5px; color:var(--text-2); font-weight:600; display:flex; align-items:center; gap:7px; font-family:var(--font); }
.op-actions { display:flex; align-items:center; gap:8px; }
.op-detail-group { display:flex; gap:2px; background:var(--bg-2); border-radius:6px; padding:2px; border:1px solid var(--border); }
.op-detail-btn { min-width:44px; min-height:44px; padding:3px 9px; border-radius:4px; border:none; font-size:11px; font-weight:600; cursor:pointer; transition:all .15s; font-family:var(--font); background:transparent; color:var(--text-3); }
.op-detail-btn:hover { color:var(--text-2); }
.op-detail-btn.active { background:rgba(255,255,255,0.1); color:var(--text); }
.op-copy { display:flex; align-items:center; justify-content:center; gap:5px; min-width:44px; min-height:44px; font-size:12px; font-weight:600; padding:5px 12px; border-radius:7px; border:1px solid var(--border); background:var(--surface); color:var(--text-2); cursor:pointer; transition:all .2s; font-family:var(--font); }
.op-copy:hover { background:var(--bg-2); color:var(--text); }
.op-copy.done { background:var(--accent-3); color:#fff; border-color:transparent; }
.op-body { padding:14px 16px; font-family:var(--mono); font-size:11.5px; line-height:1.75; color:var(--text-2); white-space:pre-wrap; word-break:break-word; min-height:96px; max-height:200px; overflow-y:auto; }
.op-body .k { color:var(--accent-2); font-weight:600; }
.op-body .h { color:var(--accent); font-weight:700; }
.op-body .c { color:var(--accent-3); }
.op-body .n { color:#c08b30; }
.op-hint { padding:0 16px 14px; font-size:12px; color:var(--text-3); font-family:var(--font); }
.op-hint.hidden { display:none; }

/* ============ 痛点 ============ */
.pain { max-width:900px; margin:0 auto; padding:90px 28px; text-align:center; }
.pain-quote {
  font-size:clamp(20px,2.6vw,30px); font-weight:700; line-height:1.5; color:var(--text);
  position:relative; padding:0 20px;
  font-family:var(--font);
}
.q-mark { color:var(--accent); font-size:1.4em; font-weight:700; opacity:0.6; }
.pain-sub { margin-top:18px; color:var(--text-2); font-size:15px; }
.pain-grid { margin-top:44px; display:grid; grid-template-columns:1fr 1fr; gap:20px; }
.pain-card { background:var(--surface); border:1px solid var(--border); border-radius:16px; padding:28px; text-align:left; transition:transform .3s var(--ease), border-color .3s, box-shadow .3s; }
.pain-card:hover { transform:translateY(-4px); border-color:var(--border-strong); box-shadow:0 8px 24px rgba(0,0,0,0.25); }
.pain-ic { font-size:30px; margin-bottom:14px; }
.pain-card h3 { font-size:18px; margin-bottom:8px; font-family:var(--font); }
.pain-card p { color:var(--text-2); font-size:14.5px; line-height:1.6; }

/* ============ 工作流 ============ */
.how { max-width:1100px; margin:0 auto; padding:80px 28px; }
.steps { display:flex; align-items:stretch; gap:18px; justify-content:center; }
.step { flex:1; background:var(--surface); border:1px solid var(--border); border-radius:18px; padding:30px 26px; transition:transform .3s var(--ease), border-color .3s, box-shadow .3s; }
.step:hover { transform:translateY(-6px); border-color:var(--border-strong); box-shadow:0 12px 32px rgba(0,0,0,0.3); }
.step-num { font-size:34px; font-weight:700; color:var(--accent); letter-spacing:-1px; font-family:var(--font); }
.step h3 { font-size:19px; margin:12px 0 8px; font-family:var(--font); }
.step p { color:var(--text-2); font-size:14px; line-height:1.6; }
.step-arrow { display:flex; align-items:center; font-size:26px; color:var(--text-3); }

/* ============ 两种模式 ============ */
.modes { max-width:1100px; margin:0 auto; padding:80px 28px; }
.mode-cards { display:grid; grid-template-columns:1fr 1fr; gap:24px; }
.mode-card { position:relative; border-radius:20px; padding:34px; overflow:hidden; border:1px solid var(--border); background:var(--surface); transition:transform .3s var(--ease), box-shadow .3s; }
.mode-card:hover { transform:translateY(-6px); }
.mode-card.text:hover { box-shadow:0 12px 32px rgba(217,119,87,0.15); }
.mode-card.image:hover { box-shadow:0 12px 32px rgba(106,155,204,0.15); }
.mode-tag { display:inline-block; font-size:12.5px; font-weight:600; padding:5px 13px; border-radius:999px; margin-bottom:16px; font-family:var(--font); }
.mode-card.text .mode-tag { background:rgba(217,119,87,0.1); color:var(--mode-text); }
.mode-card.image .mode-tag { background:rgba(106,155,204,0.1); color:var(--mode-image); }
.mode-card h3 { font-size:22px; margin-bottom:12px; position:relative; font-family:var(--font); }
.mode-card > p { color:var(--text-2); font-size:14.5px; line-height:1.65; position:relative; }
.mode-list { list-style:none; margin-top:18px; display:flex; flex-direction:column; gap:9px; position:relative; }
.mode-list li { font-size:14px; color:var(--text-2); padding-left:24px; position:relative; }
.mode-list li::before { content:'✓'; position:absolute; left:0; font-weight:700; }
.mode-card.text .mode-list li::before { color:var(--mode-text); }
.mode-card.image .mode-list li::before { color:var(--mode-image); }

/* ============ 特性 ============ */
.features { max-width:1100px; margin:0 auto; padding:80px 28px; }
.feat-grid { display:grid; grid-template-columns:repeat(3,1fr); gap:18px; }
.feat { background:var(--surface); border:1px solid var(--border); border-radius:16px; padding:26px; transition:transform .3s var(--ease), border-color .3s, box-shadow .3s; }
.feat:hover { transform:translateY(-5px); border-color:var(--border-strong); box-shadow:0 8px 24px rgba(0,0,0,0.25); }
.feat-ic { font-size:26px; margin-bottom:12px; }
.feat h3 { font-size:16px; margin-bottom:7px; font-family:var(--font); }
.feat p { color:var(--text-2); font-size:13.5px; line-height:1.55; }

/* ============ 下载 CTA ============ */
.download { max-width:1100px; margin:0 auto; padding:90px 28px 110px; }
.dl-card { position:relative; text-align:center; border-radius:28px; padding:60px 40px; overflow:hidden; border:1px solid var(--border); background:var(--surface); }
.dl-logo { width:72px; height:72px; position:relative; margin-bottom:22px; }
.dl-card h2 { font-size:clamp(26px,3.2vw,38px); font-weight:700; letter-spacing:-0.5px; position:relative; font-family:var(--font); }
.dl-card > p { margin:14px 0 30px; color:var(--text-2); font-size:16px; position:relative; }
.dl-meta { margin-top:18px; font-size:13px; color:var(--text-3); position:relative; font-family:var(--font); }

/* ============ 页脚 ============ */
.footer { max-width:1100px; margin:0 auto; padding:50px 28px 60px; text-align:center; border-top:1px solid var(--border); }
.footer .brand { justify-content:center; margin-bottom:14px; }
.footer .brand-logo { width:26px; height:26px; }
.footer-tagline { color:var(--text-2); font-size:14px; }
.footer-copy { margin-top:8px; color:var(--text-3); font-size:12.5px; font-family:var(--font); }

/* ============ 滚动揭示 ============ */
.reveal { opacity:0; transform:translateY(30px) scale(0.98); transition:opacity .8s var(--ease), transform .8s var(--spring); }
.reveal.in { opacity:1; transform:none; }

/* ============ 响应式 ============ */
@media (max-width:900px) {
  .nav { background:rgba(20,20,19,0.92); border-bottom-color:var(--border); }
  .nav-inner { position:relative; padding:10px 18px; gap:12px; }
  .nav-menu-toggle { display:flex; margin-left:auto; }
  .nav-links {
    position:absolute; top:calc(100% + 8px); left:18px; right:18px;
    display:flex; flex-direction:column; gap:4px; margin-left:0;
    padding:8px; border-radius:12px; background:rgba(28,28,26,0.98);
    border:1px solid var(--border); box-shadow:0 16px 36px rgba(0,0,0,0.28);
    opacity:0; transform:translateY(-6px); pointer-events:none;
    transition:opacity .18s var(--ease), transform .18s var(--ease);
  }
  .nav-links.open { opacity:1; transform:translateY(0); pointer-events:auto; }
  .nav-links a { min-height:44px; display:flex; align-items:center; padding:0 10px; border-radius:8px; }
  .nav-links a:hover { background:var(--surface); }
  .nav-links a::after { display:none; }
  .hero { grid-template-columns:1fr; padding-top:80px; gap:40px; min-height:auto; }
  .pain-grid, .mode-cards { grid-template-columns:1fr; }
  .feat-grid { grid-template-columns:1fr 1fr; }
  .steps { flex-direction:column; }
  .step-arrow { transform:rotate(90deg); justify-content:center; }
  #flowBg { opacity:0.56; }
}
@media (max-width:560px) {
  .feat-grid { grid-template-columns:1fr; }
  .browser-body { height:360px; }
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity:1; transform:none; }
}

/* ============ Changelog ============ */
.changelog-entry { margin-bottom: 48px; }
.changelog-header { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; }
.changelog-version {
  background: var(--accent); color: white; padding: 4px 12px; border-radius: 20px;
  font-size: 0.85rem; font-weight: 600;
}
.changelog-date { color: var(--text-muted); font-size: 0.9rem; }
.changelog-entry h2 {
  font-size: 1.5rem; font-weight: 600; margin-bottom: 16px; color: var(--text);
}
.changelog-entry ul { list-style: none; padding: 0; }
.changelog-item {
  padding: 8px 0; border-bottom: 1px solid var(--border);
  display: flex; align-items: flex-start; gap: 12px;
}
.changelog-tag { flex-shrink: 0; white-space: nowrap; min-width: 52px; }
.changelog-tag-fix { color: var(--accent); font-weight: 500; }
.changelog-tag-feat { color: var(--accent); font-weight: 500; }
/* 实验标签：柔和警示色，与稳定特性区分 */
.changelog-tag-exp { color: var(--accent-2); font-weight: 500; }
.changelog-tag-opt { color: var(--text-muted); font-weight: 500; }

/* ============ Hero Scenarios ============ */
.hero-scenarios { margin-top: 32px; }
.scenarios-title { font-size: 16px; font-weight: 600; margin-bottom: 16px; color: var(--text); }
.scenarios-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.scenario-card { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 20px; }
.scenario-card-title { font-size: 14px; font-weight: 600; margin-bottom: 12px; }
.scenario-card-title.text { color: var(--accent); }
.scenario-card-title.image { color: var(--accent-2); }
.scenario-steps { list-style: none; counter-reset: step; padding: 0; margin: 0; }
.scenario-step {
  counter-increment: step; display: flex; align-items: flex-start; gap: 10px;
  margin-bottom: 10px; font-size: 14px; color: var(--text-2);
}
.scenario-step::before {
  content: counter(step); width: 20px; height: 20px; border-radius: 50%;
  background: var(--surface-2); border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; color: var(--text-3); flex-shrink: 0;
}
@media (max-width: 768px) {
  .scenarios-grid { grid-template-columns: 1fr; }
}

/* ============ Breadcrumb ============ */
.breadcrumb { font-size: 14px; color: var(--text-2); margin-bottom: 16px; }
.breadcrumb a { color: var(--text-2); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }