*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --coral:#FF6B6B;--coral-d:#e05555;--teal:#4ECDC4;--teal-d:#38b2aa;
  --amber:#FFB800;
  --navy:#1A1A2E;--navy-l:#16213E;--white:#FFFFFF;--off:#F7F9FC;
  --muted:#8892A4;--border:#E4EAF2;--text:#1E2A3A;
  --grad:linear-gradient(135deg,#FF6B6B 0%,#FF8E53 50%,#4ECDC4 100%);
  --card-shadow:0 4px 20px rgba(0,0,0,0.07);
  --card-shadow-h:0 8px 32px rgba(78,205,196,0.22);
  --radius:16px
}
.dark{--off:#0f1523;--white:#1a2235;--border:#2a3a5a;--text:#e4eaf2;--muted:#7a8fa8;--card-shadow:0 4px 20px rgba(0,0,0,0.3);--card-shadow-h:0 8px 32px rgba(78,205,196,0.18)}
html{scroll-behavior:smooth}
body{font-family:'Segoe UI',system-ui,-apple-system,sans-serif;background:var(--off);color:var(--text);transition:background .35s,color .35s;min-height:100vh;display:flex;flex-direction:column}
main{flex:1}

/* Header */
header{position:sticky;top:0;z-index:200;display:flex;align-items:center;justify-content:space-between;padding:0 32px;height:64px;background:var(--white);border-bottom:1px solid var(--border);box-shadow:0 2px 12px rgba(0,0,0,0.06);transition:background .35s,border-color .35s}
.logo{display:flex;align-items:center;gap:10px;font-size:22px;font-weight:800;letter-spacing:-.5px;text-decoration:none;color:var(--text)}
.logo-icon{width:36px;height:36px;border-radius:10px;background:var(--navy);display:flex;align-items:center;justify-content:center;flex-shrink:0;box-shadow:0 2px 10px rgba(255,184,0,0.25)}
.logo-icon svg{width:20px;height:20px;fill:var(--amber);filter:drop-shadow(0 0 4px rgba(255,184,0,0.5))}
.logo .accent{color:var(--coral)}
.header-right{display:flex;align-items:center;gap:16px}
.nav-links{display:flex;gap:22px;align-items:center}
.nav-links a{color:var(--muted);text-decoration:none;font-size:14px;font-weight:500;transition:color .2s}
.nav-links a:hover{color:var(--teal)}
.theme-btn{background:none;border:none;cursor:pointer;width:38px;height:38px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:18px;color:var(--text);transition:background .2s}
.theme-btn:hover{background:var(--border)}
.cta-btn{background:var(--grad);color:#fff;border:none;padding:9px 20px;border-radius:24px;font-size:14px;font-weight:600;cursor:pointer;letter-spacing:.2px;transition:opacity .2s,transform .15s;text-decoration:none;display:inline-block}
.cta-btn:hover{opacity:.88;transform:translateY(-1px)}
.cta-btn:disabled{opacity:.4;cursor:not-allowed;transform:none}

/* Footer */
footer{background:var(--navy-l,#16213E);color:rgba(255,255,255,0.55);padding:40px 32px;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px;font-size:13px}
.footer-logo{display:flex;align-items:center;gap:8px;font-size:18px;font-weight:800;color:#fff;text-decoration:none}
.footer-logo svg{width:18px;height:18px;fill:var(--amber)}
.footer-links{display:flex;gap:20px;flex-wrap:wrap}
.footer-links a{color:rgba(255,255,255,0.5);text-decoration:none;transition:color .2s}
.footer-links a:hover{color:var(--teal)}
.footer-right{color:rgba(255,255,255,0.35)}

/* Content pages */
.content{max-width:820px;margin:0 auto;padding:60px 24px 80px}
.content h1{font-size:36px;font-weight:800;letter-spacing:-1px;margin-bottom:14px}
.content .updated{color:var(--muted);font-size:13px;margin-bottom:32px}
.content h2{font-size:22px;font-weight:700;margin:36px 0 12px;letter-spacing:-.3px}
.content h3{font-size:17px;font-weight:700;margin:22px 0 8px}
.content p{line-height:1.7;margin-bottom:14px;color:var(--text)}
.content ul{padding-left:22px;margin-bottom:14px}
.content li{line-height:1.7;margin-bottom:6px}
.content a{color:var(--teal-d);text-decoration:underline}
.content a:hover{color:var(--coral)}
.back-link{display:inline-flex;align-items:center;gap:6px;color:var(--muted);text-decoration:none;font-size:14px;margin-bottom:20px;transition:color .2s}
.back-link:hover{color:var(--teal)}

@media(max-width:640px){
  header{padding:0 16px}
  .nav-links{display:none}
  footer{flex-direction:column;text-align:center}
  .content{padding:40px 18px 60px}
  .content h1{font-size:28px}
}