:root{--bg:#fff;--bg-alt:#f5f7fa;--card-bg:#fff;--text:#2d3436;--text-muted:#6b7280;--heading:#2c3e50;--accent:#3498db;--accent-soft:#3498db1f;--border:#e5e7eb;--nav-bg:#ffffffeb;--nav-text:#2c3e50;--shadow:0 2px 12px #00000014;--hero-text:#fff;--primary-color:#2c3e50;--secondary-color:#3498db;--text-color:#2d3436;--light-gray:#f5f7fa;--timeline-color:#3498db;--nav-shadow:0 2px 12px #00000014}html[data-theme=dark]{--bg:#14181f;--bg-alt:#1b212b;--card-bg:#212936;--text:#d7dce2;--text-muted:#9aa4b2;--heading:#e8edf2;--accent:#5dade2;--accent-soft:#5dade226;--border:#313b4a;--nav-bg:#14181feb;--nav-text:#e8edf2;--shadow:0 2px 12px #0006;--primary-color:#e8edf2;--secondary-color:#5dade2;--text-color:#d7dce2;--light-gray:#1b212b;--nav-shadow:0 2px 12px #0006}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:72px}body{color:var(--text);background-color:var(--bg);margin:0;padding:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Open Sans,Roboto,Helvetica,Arial,sans-serif;line-height:1.65;transition:background-color .3s,color .3s}h1,h2,h3{color:var(--heading)}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}.container{max-width:1000px;margin:0 auto;padding:0 24px}main section{padding:64px 0;scroll-margin-top:96px}.page-head{text-align:center;max-width:1000px;margin:0 auto;padding:48px 24px 8px}.page-head .eyebrow{letter-spacing:.14em;text-transform:uppercase;color:var(--accent);margin:0 0 10px;font-size:.8rem;font-weight:700}.page-head h1{letter-spacing:-.02em;margin:0 0 14px;font-size:clamp(1.9rem,5vw,2.75rem);font-weight:800}.page-head .lead{max-width:640px;color:var(--text-muted);margin:0 auto;font-size:1.05rem}.tab-bar-wrap{z-index:60;background-color:var(--bg);border-bottom:1px solid var(--border);margin-top:32px;position:sticky;top:52px}.tab-bar{flex-wrap:wrap;gap:4px;max-width:1000px;margin:0 auto;padding:0 24px;display:flex}.tab-bar a{color:var(--text-muted);padding:14px 16px;font-size:.95rem;font-weight:600;transition:color .25s;position:relative}.tab-bar a:hover{color:var(--accent);text-decoration:none}.tab-bar a.active{color:var(--accent)}.tab-bar a.active:after{content:"";background:var(--accent);border-radius:2px 2px 0 0;height:3px;position:absolute;bottom:-1px;left:12px;right:12px}.tab-bar a:focus-visible{outline:2px solid var(--accent);outline-offset:-2px;border-radius:6px}.panel-note{color:var(--text-muted);text-align:center;margin:28px 0 0;font-size:.9rem}.btn-link{border:1px solid var(--border);background:var(--card-bg);color:var(--text);box-shadow:var(--shadow);cursor:pointer;border-radius:24px;align-items:center;gap:8px;padding:10px 20px;font-family:inherit;font-weight:600;transition:transform .25s,color .25s,border-color .25s;display:inline-flex}.btn-link:hover{color:var(--accent);border-color:var(--accent);text-decoration:none;transform:translateY(-3px)}.btn-link.compact{border-radius:20px;padding:8px 16px;font-size:.9rem}.lang-toggle{appearance:none;cursor:pointer;color:var(--nav-text);font:inherit;letter-spacing:.02em;background:0 0;border:2px solid;border-radius:999px;flex-shrink:0;justify-content:center;align-items:center;min-width:42px;padding:5px 10px;font-size:.78rem;font-weight:700;line-height:1;transition:color .25s,background-color .25s,transform .15s;display:inline-flex}.lang-toggle:hover{background-color:var(--accent-soft)}.lang-toggle:active{transform:scale(.94)}.theme-toggle{cursor:pointer;color:var(--nav-text);background:0 0;border:none;border-radius:50%;flex-shrink:0;align-items:center;padding:10px;transition:color .25s,background-color .25s;display:inline-flex}.theme-toggle:hover{background-color:var(--accent-soft)}.theme-toggle svg{fill:currentColor;width:20px;height:20px}html[data-theme=dark] .icon-sun{display:block}html[data-theme=dark] .icon-moon,.icon-sun{display:none}.icon-moon{display:block}.section{padding:64px 0}.section-title{text-align:center;margin:0 0 8px;font-size:2rem}.section-rule{background:var(--accent);border:none;border-radius:2px;width:56px;height:3px;margin:0 auto 40px}.section-alt{background-color:var(--bg-alt)}.keyword-tag{background:var(--accent-soft);color:var(--accent);border-radius:14px;margin:0 6px 6px 0;padding:3px 12px;font-size:.88em;font-weight:600;display:inline-block}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}