/* ============================================================
   im.io 官网样式 - 复用管理后台设计系统色板
   ============================================================ */
:root {
  --bg-deep: #eef1fa;
  --bg-body: #f4f6fc;
  --bg-panel: rgba(255,255,255,.86);
  --bg-card: rgba(255,255,255,.92);
  --bg-dark: #0f172a;
  --bg-dark-2: #1e293b;
  --line: rgba(100,116,139,.14);
  --line-strong: rgba(100,116,139,.28);
  --text: #1e293b;
  --text-dim: #64748b;
  --text-faint: #94a3b8;
  --text-light: #f1f5f9;
  --text-light-dim: #94a3b8;
  --primary: #6366f1;
  --primary-2: #8b5cf6;
  --accent: #0ea5e9;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --pink: #f472b6;
  --radius: 14px;
  --radius-sm: 9px;
  --radius-lg: 24px;
  --glow-primary: 0 6px 20px rgba(99,102,241,.22);
  --glow-accent: 0 6px 20px rgba(14,165,233,.2);
  --grad-brand: linear-gradient(135deg,#6366f1 0%,#8b5cf6 55%,#d946ef 100%);
  --grad-accent: linear-gradient(135deg,#0ea5e9,#6366f1);
  --grad-deep: linear-gradient(160deg,#f4f6fc 0%,#eef1fa 60%,#f2f0fb 100%);
  --grad-dark: linear-gradient(160deg,#0f172a 0%,#1e1b4b 50%,#0f172a 100%);
  --shadow-card: 0 8px 24px rgba(30,41,59,.07);
  --shadow-hover: 0 16px 48px rgba(99,102,241,.15);
  --font: -apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif;
  --max-w: 1200px;
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--text);background:var(--bg-body);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}

/* ---------- Nav ---------- */
.site-nav{position:fixed;top:0;left:0;right:0;z-index:1000;height:64px;display:flex;align-items:center;justify-content:space-between;padding:0 32px;background:rgba(255,255,255,.85);backdrop-filter:blur(12px);border-bottom:1px solid var(--line);transition:box-shadow .3s}
.site-nav.scrolled{box-shadow:0 2px 20px rgba(30,41,59,.06)}
.nav-logo{display:flex;align-items:center;gap:10px;font-size:20px;font-weight:700;letter-spacing:-.02em}
.nav-logo .logo-mark{width:36px;height:36px;border-radius:10px;background:var(--grad-brand);display:flex;align-items:center;justify-content:center;color:#fff;font-size:18px;font-weight:800;box-shadow:var(--glow-primary)}
.nav-logo .logo-text{background:var(--grad-brand);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.nav-links{display:flex;align-items:center;gap:8px}
.nav-links a{padding:8px 16px;border-radius:var(--radius-sm);font-size:14px;font-weight:500;transition:all .2s}
.nav-links a:hover{color:var(--primary);background:var(--bg-hover)}
.nav-cta{padding:8px 20px;border-radius:var(--radius-sm);background:var(--grad-brand);color:#fff;font-size:14px;font-weight:600;box-shadow:var(--glow-primary);transition:transform .2s}
.nav-cta:hover{transform:translateY(-1px)}
.nav-mobile-toggle{display:none;font-size:24px;background:none;border:none;cursor:pointer;color:var(--text)}
@media(max-width:768px){
  .nav-links{display:none;position:absolute;top:64px;left:0;right:0;flex-direction:column;background:#fff;padding:16px;border-bottom:1px solid var(--line);gap:4px}
  .nav-links.open{display:flex}
  .nav-mobile-toggle{display:block}
}

/* ---------- Hero ---------- */
.hero{position:relative;padding:120px 32px 80px;overflow:hidden;background:var(--grad-deep)}
.hero::before{content:'';position:absolute;inset:0;background:radial-gradient(1000px 500px at 15% -10%,rgba(99,102,241,.10),transparent 55%),radial-gradient(900px 450px at 105% 0%,rgba(14,165,233,.08),transparent 50%);pointer-events:none}
.hero-inner{max-width:var(--max-w);margin:0 auto;display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center;position:relative}
.hero-badge{display:inline-flex;align-items:center;gap:6px;padding:6px 14px;border-radius:20px;background:rgba(99,102,241,.1);color:var(--primary);font-size:13px;font-weight:600;margin-bottom:20px}
.hero-badge .dot{width:6px;height:6px;border-radius:50%;background:var(--success);box-shadow:0 0 8px var(--success)}
.hero h1{font-size:48px;line-height:1.2;letter-spacing:-.03em;margin-bottom:20px}
.hero h1 .grad{background:var(--grad-brand);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.hero-sub{font-size:18px;color:var(--text-dim);margin-bottom:32px;line-height:1.7}
.hero-btns{display:flex;gap:16px;flex-wrap:wrap}
.btn-primary{padding:14px 32px;border-radius:var(--radius-sm);background:var(--grad-brand);color:#fff;font-size:15px;font-weight:600;box-shadow:var(--glow-primary);transition:transform .2s,box-shadow .2s;display:inline-flex;align-items:center;gap:8px}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 10px 30px rgba(99,102,241,.3)}
.btn-secondary{padding:14px 32px;border-radius:var(--radius-sm);background:#fff;color:var(--text);font-size:15px;font-weight:600;border:1px solid var(--line-strong);transition:all .2s;display:inline-flex;align-items:center;gap:8px}
.btn-secondary:hover{border-color:var(--primary);color:var(--primary);background:var(--bg-hover)}
.hero-visual{position:relative}
.hero-mockup{background:var(--bg-card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow-card);overflow:hidden;position:relative}
.hero-mockup-bar{height:40px;background:var(--bg-deep);display:flex;align-items:center;padding:0 16px;gap:8px;border-bottom:1px solid var(--line)}
.hero-mockup-bar span{width:12px;height:12px;border-radius:50%;background:#ddd}
.hero-mockup-bar span:nth-child(1){background:#ff5f57}
.hero-mockup-bar span:nth-child(2){background:#ffbd2e}
.hero-mockup-bar span:nth-child(3){background:#28c940}
.hero-mockup-body{padding:20px;display:flex;flex-direction:column;gap:12px}
.mockup-msg{display:flex;gap:8px;align-items:flex-start;max-width:80%}
.mockup-msg.visitor{align-self:flex-end;flex-direction:row-reverse}
.mockup-avatar{width:32px;height:32px;border-radius:50%;background:var(--grad-accent);flex-shrink:0;display:flex;align-items:center;justify-content:center;color:#fff;font-size:14px;font-weight:600}
.mockup-msg.visitor .mockup-avatar{background:var(--grad-brand)}
.mockup-bubble{padding:10px 14px;border-radius:var(--radius-sm);font-size:13px;line-height:1.5}
.mockup-msg:not(.visitor) .mockup-bubble{background:#f1f5f9;color:var(--text)}
.mockup-msg.visitor .mockup-bubble{background:var(--grad-brand);color:#fff}
.mockup-system{text-align:center;font-size:12px;color:var(--text-faint);padding:4px}
@media(max-width:900px){
  .hero-inner{grid-template-columns:1fr;text-align:center}
  .hero h1{font-size:36px}
  .hero-visual{display:none}
}

/* ---------- Section ---------- */
.section{padding:80px 32px}
.section-inner{max-width:var(--max-w);margin:0 auto}
.section-head{text-align:center;margin-bottom:48px}
.section-head .label{display:inline-block;padding:4px 12px;border-radius:16px;background:rgba(99,102,241,.1);color:var(--primary);font-size:13px;font-weight:600;margin-bottom:12px}
.section-head h2{font-size:36px;letter-spacing:-.02em;margin-bottom:12px}
.section-head p{font-size:16px;color:var(--text-dim);max-width:640px;margin:0 auto}

/* ---------- Features Grid ---------- */
.feat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.feat-card{background:var(--bg-card);border:1px solid var(--line);border-radius:var(--radius);padding:28px;transition:all .3s;position:relative;overflow:hidden}
.feat-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-hover);border-color:rgba(99,102,241,.2)}
.feat-card::before{content:'';position:absolute;top:0;left:0;right:0;height:3px;background:var(--grad-brand);transform:scaleX(0);transform-origin:left;transition:transform .3s}
.feat-card:hover::before{transform:scaleX(1)}
.feat-icon{width:48px;height:48px;border-radius:12px;background:var(--grad-brand);display:flex;align-items:center;justify-content:center;color:#fff;font-size:22px;margin-bottom:16px;box-shadow:var(--glow-primary)}
.feat-card h3{font-size:18px;font-weight:700;margin-bottom:8px}
.feat-card p{font-size:14px;color:var(--text-dim);line-height:1.6}
.feat-card .feat-tag{display:inline-block;margin-top:12px;padding:2px 10px;border-radius:12px;background:rgba(16,185,129,.1);color:var(--success);font-size:12px;font-weight:600}
@media(max-width:900px){.feat-grid{grid-template-columns:1fr}}
@media(min-width:600px) and (max-width:900px){.feat-grid{grid-template-columns:repeat(2,1fr)}}

/* ---------- How it works ---------- */
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:32px}
.step{text-align:center;position:relative}
.step-num{width:48px;height:48px;border-radius:50%;background:var(--grad-brand);color:#fff;font-size:20px;font-weight:700;display:flex;align-items:center;justify-content:center;margin:0 auto 16px;box-shadow:var(--glow-primary)}
.step h3{font-size:18px;font-weight:700;margin-bottom:8px}
.step p{font-size:14px;color:var(--text-dim);line-height:1.6}
.step:not(:last-child)::after{content:'';position:absolute;top:24px;right:-16px;width:32px;height:2px;background:var(--line-strong)}
@media(max-width:900px){.steps{grid-template-columns:1fr}.step:not(:last-child)::after{display:none}}

/* ---------- Code Block ---------- */
.code-block{background:var(--bg-dark);border-radius:var(--radius);overflow:hidden;margin:24px 0;box-shadow:var(--shadow-card)}
.code-header{display:flex;align-items:center;justify-content:space-between;padding:10px 16px;background:rgba(255,255,255,.04);border-bottom:1px solid rgba(255,255,255,.06)}
.code-header .lang{font-size:12px;color:var(--text-faint);font-weight:600}
.code-header .copy{font-size:12px;color:var(--accent);cursor:pointer;border:none;background:none;font-family:var(--font)}
.code-header .copy:hover{color:var(--primary)}
.code-block pre{padding:20px;overflow-x:auto;font-size:13px;line-height:1.7;color:#e2e8f0;font-family:'SF Mono','Fira Code','Consolas',monospace}
.code-block .k{color:#818cf8}
.code-block .s{color:#34d399}
.code-block .c{color:#64748b;font-style:italic}
.code-block .t{color:#f0abfc}
.code-block .n{color:#fbbf24}
.code-block .p{color:#67e8f9}

/* ---------- Architecture ---------- */
.arch-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;text-align:center}
.arch-node{padding:20px;background:var(--bg-card);border:1px solid var(--line);border-radius:var(--radius-sm);transition:all .2s}
.arch-node:hover{border-color:var(--primary);box-shadow:var(--glow-primary)}
.arch-node .arch-icon{font-size:28px;margin-bottom:8px}
.arch-node h4{font-size:14px;font-weight:700;margin-bottom:4px}
.arch-node p{font-size:12px;color:var(--text-faint)}
@media(max-width:900px){.arch-grid{grid-template-columns:repeat(2,1fr)}}

/* ---------- Stats ---------- */
.stats{background:var(--grad-dark);padding:64px 32px}
.stats-inner{max-width:var(--max-w);margin:0 auto;display:grid;grid-template-columns:repeat(4,1fr);gap:24px;text-align:center}
.stat-item h3{font-size:40px;color:#fff;font-weight:800;letter-spacing:-.03em}
.stat-item h3 .grad{background:var(--grad-brand);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.stat-item p{font-size:14px;color:var(--text-light-dim);margin-top:4px}
@media(max-width:900px){.stats-inner{grid-template-columns:repeat(2,1fr)}}

/* ---------- CTA ---------- */
.cta{padding:80px 32px;text-align:center}
.cta-inner{max-width:720px;margin:0 auto;background:var(--grad-brand);border-radius:var(--radius-lg);padding:48px;position:relative;overflow:hidden}
.cta-inner::before{content:'';position:absolute;inset:0;background:radial-gradient(circle at 30% 20%,rgba(255,255,255,.15),transparent 50%)}
.cta-inner h2{color:#fff;font-size:32px;margin-bottom:12px;position:relative}
.cta-inner p{color:rgba(255,255,255,.85);font-size:16px;margin-bottom:24px;position:relative}
.cta-inner .btn-white{padding:14px 32px;border-radius:var(--radius-sm);background:#fff;color:var(--primary);font-weight:700;font-size:15px;display:inline-flex;align-items:center;gap:8px;position:relative;transition:transform .2s}
.cta-inner .btn-white:hover{transform:translateY(-2px)}

/* ---------- Footer ---------- */
.site-footer{background:var(--bg-dark);color:var(--text-light-dim);padding:48px 32px 24px}
.footer-inner{max-width:var(--max-w);margin:0 auto}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:32px;margin-bottom:32px}
.footer-brand .nav-logo{margin-bottom:12px}
.footer-brand .nav-logo .logo-text{background:var(--grad-brand);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.footer-brand p{font-size:13px;line-height:1.6}
.footer-col h4{color:#fff;font-size:14px;font-weight:700;margin-bottom:12px}
.footer-col a{display:block;font-size:13px;padding:4px 0;color:var(--text-light-dim);transition:color .2s}
.footer-col a:hover{color:var(--primary)}
.footer-bottom{border-top:1px solid rgba(255,255,255,.06);padding-top:16px;text-align:center;font-size:12px}
@media(max-width:768px){.footer-grid{grid-template-columns:1fr 1fr}}

/* ---------- Docs Page ---------- */
.docs-layout{max-width:var(--max-w);margin:0 auto;padding:80px 32px 48px;display:grid;grid-template-columns:240px 1fr;gap:40px}
.docs-sidebar{position:sticky;top:80px;max-height:calc(100vh - 96px);overflow-y:auto;padding-right:8px}
.docs-sidebar h4{font-size:12px;text-transform:uppercase;letter-spacing:.05em;color:var(--text-faint);margin:20px 0 8px;font-weight:700}
.docs-sidebar a{display:block;padding:6px 12px;border-radius:6px;font-size:14px;color:var(--text-dim);transition:all .15s}
.docs-sidebar a:hover{color:var(--primary);background:var(--bg-hover)}
.docs-sidebar a.active{color:var(--primary);font-weight:600;background:rgba(99,102,241,.08)}
.docs-content{min-width:0}
.docs-content h2{font-size:28px;margin:40px 0 16px;padding-top:20px;border-top:1px solid var(--line)}
.docs-content h2:first-child{border-top:none;padding-top:0;margin-top:0}
.docs-content h3{font-size:20px;margin:24px 0 12px}
.docs-content p{margin-bottom:12px;color:var(--text-dim);line-height:1.7}
.docs-content ul{margin:0 0 16px 20px;color:var(--text-dim)}
.docs-content li{margin-bottom:6px}
.docs-content table{width:100%;border-collapse:collapse;margin:16px 0;font-size:13px}
.docs-content th,.docs-content td{border:1px solid var(--line);padding:8px 12px;text-align:left}
.docs-content th{background:var(--bg-deep);font-weight:700;color:var(--text)}
.docs-content td{color:var(--text-dim)}
.docs-content code{background:rgba(99,102,241,.08);color:var(--primary);padding:2px 6px;border-radius:4px;font-family:'SF Mono','Fira Code','Consolas',monospace;font-size:13px}
.docs-content .note{padding:12px 16px;border-radius:var(--radius-sm);background:rgba(14,165,233,.06);border-left:3px solid var(--accent);margin:16px 0;font-size:14px}
.docs-content .note strong{color:var(--accent)}
@media(max-width:900px){.docs-layout{grid-template-columns:1fr;padding-top:64px}.docs-sidebar{display:none}}

/* ---------- Scroll Animation ---------- */
.fade-in{opacity:0;transform:translateY(20px);transition:opacity .6s,transform .6s}
.fade-in.visible{opacity:1;transform:translateY(0)}