/* =====================================================================
   fzkaipeng.com - Global Stylesheet
   Aesthetic: Computer-science x immersive full-screen cinematic
   ===================================================================== */

:root {
    --bg-0: #05070d;
    --bg-1: #0a0f1c;
    --bg-2: #0f1626;
    --panel: rgba(255, 255, 255, 0.03);
    --panel-strong: rgba(255, 255, 255, 0.06);
    --border: rgba(120, 160, 255, 0.12);
    --border-strong: rgba(120, 160, 255, 0.28);
    --text: #e6ecf5;
    --text-dim: #9aa6b8;
    --text-faint: #6a7588;
    --accent: #5cc8ff;
    --accent-2: #7d6cff;
    --accent-3: #58e1c4;
    --warn: #ffb86b;
    --danger: #ff6b8b;
    --code-bg: #0b1120;
    --mono: 'JetBrains Mono', 'Fira Code', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    --sans: 'Inter', 'Helvetica Neue', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
    --display: 'Space Grotesk', 'Inter', system-ui, sans-serif;
    --ease: cubic-bezier(.2, .7, .2, 1);
    --grid: linear-gradient(rgba(120,160,255,.05) 1px, transparent 1px),
            linear-gradient(90deg, rgba(120,160,255,.05) 1px, transparent 1px);
}

[data-theme="light"] {
    --bg-0: #f4f6fb;
    --bg-1: #eef2f9;
    --bg-2: #e6ecf5;
    --panel: rgba(10, 20, 40, 0.03);
    --panel-strong: rgba(10, 20, 40, 0.06);
    --border: rgba(10, 20, 40, 0.1);
    --border-strong: rgba(10, 20, 40, 0.22);
    --text: #0b1220;
    --text-dim: #4b556a;
    --text-faint: #6a7588;
    --accent: #0d6efd;
    --accent-2: #6a4cff;
    --accent-3: #0aa884;
    --code-bg: #0b1120;
}

* { box-sizing: border-box; }
*::selection { background: var(--accent); color: #001; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
    background: var(--bg-0);
    color: var(--text);
    font-family: var(--sans);
    font-size: 16px;
    line-height: 1.65;
    letter-spacing: 0.01em;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    min-height: 100vh;
    position: relative;
}

body::before {
    content: ''; position: fixed; inset: 0;
    background:
        radial-gradient(1200px 600px at 80% -10%, rgba(93, 80, 255, 0.18), transparent 60%),
        radial-gradient(900px 500px at -10% 30%, rgba(0, 200, 255, 0.12), transparent 60%),
        radial-gradient(800px 500px at 50% 110%, rgba(90, 230, 200, 0.10), transparent 60%);
    z-index: -2; pointer-events: none;
}

body::after {
    content: ''; position: fixed; inset: 0;
    background-image: var(--grid);
    background-size: 64px 64px;
    mask-image: radial-gradient(ellipse at center, rgba(0,0,0,1) 30%, rgba(0,0,0,0) 80%);
    -webkit-mask-image: radial-gradient(ellipse at center, rgba(0,0,0,1) 30%, rgba(0,0,0,0) 80%);
    opacity: .55; z-index: -1; pointer-events: none;
}

a { color: var(--accent); text-decoration: none; transition: color .25s var(--ease); }
a:hover { color: var(--accent-3); }
img, svg { max-width: 100%; display: block; }

h1, h2, h3, h4, h5 {
    font-family: var(--display); font-weight: 600; line-height: 1.15;
    margin: 0 0 .6em; color: var(--text); letter-spacing: -0.01em;
}
h1 { font-size: clamp(2.4rem, 5vw, 4.6rem); letter-spacing: -0.03em; }
h2 { font-size: clamp(1.8rem, 3.4vw, 2.8rem); }
h3 { font-size: clamp(1.25rem, 2vw, 1.55rem); }
p { margin: 0 0 1em; color: var(--text-dim); }
code { font-family: var(--mono); background: var(--code-bg); color: #cde6ff; padding: 2px 6px; border-radius: 4px; font-size: .92em; }
pre { background: var(--code-bg); border: 1px solid var(--border); border-radius: 10px; padding: 16px; overflow: auto; }
pre code { background: transparent; padding: 0; }
.container { width: min(1240px, 92vw); margin: 0 auto; }

/* ================== NAV ================== */
.nav {
    position: fixed; top: 18px; left: 50%; transform: translateX(-50%);
    width: min(1240px, 92vw); z-index: 50;
    background: linear-gradient(180deg, rgba(10,15,28,.78), rgba(10,15,28,.55));
    backdrop-filter: blur(18px) saturate(140%);
    -webkit-backdrop-filter: blur(18px) saturate(140%);
    border: 1px solid var(--border);
    border-radius: 16px; padding: 12px 18px;
    display: flex; align-items: center; gap: 18px;
    transition: padding .3s var(--ease), background .3s var(--ease);
}
.nav.scrolled { padding: 8px 14px; }
.nav-brand { display: flex; align-items: center; gap: 10px; font-family: var(--display); font-weight: 600; color: var(--text); font-size: 1.02rem; }
.nav-brand svg { width: 28px; height: 28px; }
.nav-brand .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent-3); box-shadow: 0 0 12px var(--accent-3); animation: pulse 2.2s infinite; }
.nav-links { margin-left: auto; display: flex; gap: 6px; align-items: center; }
.nav-links a { color: var(--text-dim); padding: 8px 14px; border-radius: 8px; font-size: .92rem; font-weight: 500; position: relative; transition: color .25s var(--ease), background .25s var(--ease); }
.nav-links a:hover, .nav-links a.active { color: var(--text); background: var(--panel-strong); }
.nav-links a.active::after { content: ''; position: absolute; left: 14px; right: 14px; bottom: 2px; height: 2px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); border-radius: 2px; }
.nav-cta { margin-left: 6px; display: inline-flex; align-items: center; gap: 6px; padding: 8px 14px; border: 1px solid var(--border-strong); border-radius: 8px; color: var(--text); font-size: .9rem; background: var(--panel-strong); transition: transform .25s var(--ease), border-color .25s var(--ease); }
.nav-cta:hover { transform: translateY(-1px); border-color: var(--accent); }
.nav-toggle { display: none; }

/* ================== HERO ================== */
.hero { min-height: 100vh; position: relative; display: flex; align-items: center; padding: 140px 0 80px; overflow: hidden; }
.hero-canvas { position: absolute; inset: 0; z-index: -1; pointer-events: none; }
.hero-inner { display: grid; grid-template-columns: 1.1fr .9fr; gap: 56px; align-items: center; width: 100%; }
.hero-eyebrow { display: inline-flex; align-items: center; gap: 10px; padding: 6px 12px; border: 1px solid var(--border); background: var(--panel); border-radius: 999px; color: var(--text-dim); font-family: var(--mono); font-size: .82rem; letter-spacing: .04em; }
.hero-eyebrow .live { width: 8px; height: 8px; border-radius: 50%; background: var(--accent-3); box-shadow: 0 0 10px var(--accent-3); animation: pulse 1.8s infinite; }
.hero h1 .grad { background: linear-gradient(135deg, #ffffff 10%, #9ad8ff 40%, #7d6cff 70%, #58e1c4 100%); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; color: transparent; }
.hero p.lead { font-size: 1.15rem; color: var(--text-dim); max-width: 56ch; margin-top: 16px; }
.hero-actions { display: flex; gap: 12px; margin-top: 28px; flex-wrap: wrap; }
.btn { display: inline-flex; align-items: center; gap: 10px; padding: 14px 22px; border-radius: 12px; font-weight: 600; font-size: .95rem; border: 1px solid transparent; cursor: pointer; user-select: none; transition: transform .25s var(--ease), background .25s var(--ease), border-color .25s var(--ease); }
.btn-primary { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #04111f; box-shadow: 0 12px 40px -12px rgba(93,200,255,.5); }
.btn-primary:hover { transform: translateY(-2px); color: #04111f; }
.btn-ghost { border-color: var(--border-strong); color: var(--text); background: var(--panel); }
.btn-ghost:hover { border-color: var(--accent); transform: translateY(-2px); }
.hero-meta { margin-top: 48px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; border-top: 1px dashed var(--border); padding-top: 24px; }
.hero-meta .m .num { font-family: var(--display); font-size: 1.8rem; font-weight: 600; background: linear-gradient(135deg, #fff, #9ad8ff); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-meta .m .lbl { color: var(--text-faint); font-size: .82rem; font-family: var(--mono); letter-spacing: .04em; text-transform: uppercase; }

/* ================== TERMINAL ================== */
.term { border: 1px solid var(--border); background: linear-gradient(180deg, rgba(255,255,255,.04), rgba(255,255,255,.02)); border-radius: 16px; overflow: hidden; box-shadow: 0 30px 80px -40px rgba(0,0,0,.8); backdrop-filter: blur(8px); }
.term-head { display: flex; align-items: center; gap: 8px; padding: 10px 14px; background: rgba(255,255,255,.04); border-bottom: 1px solid var(--border); font-family: var(--mono); font-size: .78rem; color: var(--text-faint); }
.term-head .dots { display: flex; gap: 6px; }
.term-head .dots span { width: 11px; height: 11px; border-radius: 50%; }
.term-head .dots span:nth-child(1) { background: #ff5f56; }
.term-head .dots span:nth-child(2) { background: #ffbd2e; }
.term-head .dots span:nth-child(3) { background: #27c93f; }
.term-head .path { margin-left: auto; }
.term-body { padding: 18px; font-family: var(--mono); font-size: .86rem; color: #cbe2ff; line-height: 1.7; min-height: 280px; }
.term-body .line { display: block; white-space: pre-wrap; }
.term-body .c1 { color: var(--accent-3); }
.term-body .c2 { color: var(--accent); }
.term-body .c3 { color: var(--accent-2); }
.term-body .c4 { color: #ffb86b; }
.term-body .c5 { color: var(--text-faint); }
.term-body .cursor { display: inline-block; width: 8px; height: 14px; vertical-align: middle; background: var(--accent); margin-left: 2px; animation: blink 1s steps(2) infinite; }

/* ================== SECTION ================== */
section { padding: 100px 0; position: relative; }
.section-head { max-width: 720px; margin: 0 auto 56px; text-align: center; }
.section-head .kicker { display: inline-block; font-family: var(--mono); font-size: .8rem; color: var(--accent); letter-spacing: .12em; text-transform: uppercase; padding: 4px 10px; border: 1px solid var(--border-strong); border-radius: 6px; margin-bottom: 16px; }
.section-head h2 .grad { background: linear-gradient(135deg, #fff 0%, #9ad8ff 60%, #7d6cff 100%); -webkit-background-clip: text; background-clip: text; color: transparent; }
.section-head p { font-size: 1.05rem; }

/* ================== CARDS / GRIDS ================== */
.grid { display: grid; gap: 18px; }
.cols-3 { grid-template-columns: repeat(3, 1fr); }
.cols-2 { grid-template-columns: repeat(2, 1fr); }
.cols-4 { grid-template-columns: repeat(4, 1fr); }

.card { position: relative; padding: 28px; border: 1px solid var(--border); border-radius: 14px; background: var(--panel); overflow: hidden; transition: transform .35s var(--ease), border-color .35s var(--ease), background .35s var(--ease); }
.card::before { content: ''; position: absolute; inset: 0; background: radial-gradient(600px 200px at var(--mx,50%) var(--my,0%), rgba(120,180,255,.16), transparent 60%); opacity: 0; transition: opacity .35s var(--ease); pointer-events: none; }
.card:hover { transform: translateY(-3px); border-color: var(--border-strong); }
.card:hover::before { opacity: 1; }
.card .ico { width: 48px; height: 48px; border-radius: 10px; background: linear-gradient(135deg, rgba(93,200,255,.18), rgba(125,108,255,.18)); display: flex; align-items: center; justify-content: center; color: var(--accent); margin-bottom: 16px; border: 1px solid var(--border-strong); }
.card .ico svg { width: 22px; height: 22px; }
.card h3 { margin-bottom: 8px; }
.card p { margin: 0; font-size: .95rem; }
.card .meta { margin-top: 18px; display: flex; gap: 8px; flex-wrap: wrap; font-family: var(--mono); font-size: .72rem; }
.card .tag { padding: 4px 8px; border: 1px solid var(--border); border-radius: 6px; color: var(--text-dim); }

.svc-card { min-height: 280px; }
.svc-card .num { position: absolute; right: 22px; top: 22px; font-family: var(--mono); font-size: .9rem; color: var(--text-faint); }

.feat-row { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; margin-bottom: 100px; }
.feat-row.reverse { direction: rtl; }
.feat-row.reverse > * { direction: ltr; }
.feat-row .visual { border: 1px solid var(--border); border-radius: 16px; background: var(--panel-strong); padding: 18px; position: relative; aspect-ratio: 4 / 3; overflow: hidden; }

/* ================== STATS ================== */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.stat { border: 1px solid var(--border); background: var(--panel); padding: 24px; border-radius: 14px; text-align: center; }
.stat .v { font-family: var(--display); font-size: 2.4rem; background: linear-gradient(135deg, #fff, #9ad8ff 50%, #7d6cff); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat .l { color: var(--text-faint); font-family: var(--mono); font-size: .78rem; letter-spacing: .1em; text-transform: uppercase; margin-top: 4px; }

/* ================== TIMELINE ================== */
.timeline { position: relative; padding-left: 28px; border-left: 1px dashed var(--border-strong); }
.timeline .tl-item { position: relative; padding: 0 0 28px 12px; }
.timeline .tl-item::before { content: ''; position: absolute; left: -34px; top: 6px; width: 12px; height: 12px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px rgba(93,200,255,.18); }
.timeline .date { font-family: var(--mono); font-size: .8rem; color: var(--accent); }
.timeline h4 { margin: 6px 0 6px; }
.timeline p { margin: 0; }

/* ================== CONTACT ================== */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; border: 1px solid var(--border); background: var(--panel); border-radius: 18px; padding: 36px; }
.contact-grid .field { display: block; margin-bottom: 16px; }
.contact-grid label { display: block; font-family: var(--mono); font-size: .8rem; color: var(--text-faint); margin-bottom: 6px; }
.contact-grid input, .contact-grid textarea, .contact-grid select { width: 100%; background: var(--bg-2); border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; color: var(--text); font-family: var(--sans); font-size: .95rem; outline: none; transition: border-color .25s var(--ease), background .25s var(--ease); }
.contact-grid input:focus, .contact-grid textarea:focus, .contact-grid select:focus { border-color: var(--accent); background: var(--bg-1); }
.contact-grid textarea { min-height: 130px; resize: vertical; }
.contact-grid .row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.info-block { display: flex; align-items: flex-start; gap: 14px; margin-bottom: 22px; }
.info-block .ico { flex: none; }
.info-block .lbl { font-family: var(--mono); font-size: .78rem; color: var(--text-faint); text-transform: uppercase; letter-spacing: .08em; }
.info-block .val { color: var(--text); }

/* ================== LEGAL ================== */
.legal-wrap { padding-top: 140px; padding-bottom: 80px; }
.legal-head { border-bottom: 1px solid var(--border); padding-bottom: 24px; margin-bottom: 40px; }
.legal-head .crumb { font-family: var(--mono); font-size: .82rem; color: var(--text-faint); margin-bottom: 12px; }
.legal-head h1 { font-size: clamp(2rem, 3.6vw, 3rem); }
.legal-meta { display: flex; gap: 20px; margin-top: 14px; font-family: var(--mono); font-size: .82rem; color: var(--text-faint); }
.legal-grid { display: grid; grid-template-columns: 260px 1fr; gap: 40px; }
.legal-toc { position: sticky; top: 110px; align-self: start; border: 1px solid var(--border); background: var(--panel); border-radius: 12px; padding: 18px; max-height: calc(100vh - 130px); overflow: auto; }
.legal-toc h5 { font-family: var(--mono); font-size: .75rem; letter-spacing: .12em; color: var(--text-faint); margin: 0 0 12px; text-transform: uppercase; }
.legal-toc a { display: block; color: var(--text-dim); padding: 6px 8px; border-radius: 6px; font-size: .9rem; border-left: 2px solid transparent; transition: color .25s var(--ease), border-color .25s var(--ease), background .25s var(--ease); }
.legal-toc a:hover, .legal-toc a.active { color: var(--text); background: var(--panel-strong); border-left-color: var(--accent); }
.legal-body { max-width: 880px; }
.legal-body section { padding: 30px 0 10px; border-bottom: 1px dashed var(--border); }
.legal-body section:last-child { border-bottom: 0; }
.legal-body h2 { font-size: 1.5rem; margin-top: 0; display: flex; align-items: center; gap: 12px; }
.legal-body h2 .ix { font-family: var(--mono); font-size: .8rem; color: var(--accent); padding: 4px 8px; border: 1px solid var(--border-strong); border-radius: 6px; }
.legal-body h3 { font-size: 1.1rem; margin-top: 26px; }
.legal-body p, .legal-body li { color: var(--text-dim); }
.legal-body ul, .legal-body ol { padding-left: 22px; margin: 8px 0 18px; }
.legal-body ul li, .legal-body ol li { margin-bottom: 6px; }
.legal-body .note { border-left: 3px solid var(--accent); padding: 12px 16px; background: var(--panel); border-radius: 8px; color: var(--text-dim); margin: 18px 0; }
.legal-body .pill { display: inline-block; padding: 2px 8px; background: var(--panel-strong); border: 1px solid var(--border); border-radius: 999px; font-family: var(--mono); font-size: .74rem; color: var(--accent); margin-right: 6px; margin-bottom: 4px; }
.legal-body table { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: .92rem; }
.legal-body th, .legal-body td { border: 1px solid var(--border); padding: 10px 12px; text-align: left; }
.legal-body th { background: var(--panel-strong); color: var(--text); font-weight: 600; }

/* ================== FOOTER ================== */
footer { border-top: 1px solid var(--border); margin-top: 60px; padding: 60px 0 30px; background: linear-gradient(180deg, transparent, rgba(255,255,255,.02)); }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; }
.footer-grid h6 { font-family: var(--mono); font-size: .75rem; letter-spacing: .14em; text-transform: uppercase; color: var(--text-faint); margin: 0 0 14px; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin-bottom: 8px; }
.footer-grid a { color: var(--text-dim); }
.footer-grid a:hover { color: var(--text); }
.footer-brand p { color: var(--text-dim); max-width: 36ch; font-size: .92rem; }
.footer-brand .badge { display: inline-flex; align-items: center; gap: 8px; padding: 6px 10px; border: 1px solid var(--border); border-radius: 999px; font-family: var(--mono); font-size: .78rem; color: var(--text-faint); margin-top: 16px; }
.footer-bottom { margin-top: 36px; border-top: 1px solid var(--border); padding-top: 20px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; font-family: var(--mono); font-size: .8rem; color: var(--text-faint); }

/* ================== ANIMATIONS ================== */
@keyframes pulse { 0%, 100% { transform: scale(1); opacity: 1; } 50% { transform: scale(1.35); opacity: .55; } }
@keyframes blink { 50% { opacity: 0; } }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }
@keyframes shimmer { 0% { background-position: -100% 0; } 100% { background-position: 200% 0; } }
@keyframes orbit { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
@keyframes fadeUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes spin { from { transform: rotate(0); } to { transform: rotate(360deg); } }

.reveal { opacity: 0; transform: translateY(24px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.reveal.visible { opacity: 1; transform: translateY(0); }
.shimmer-text { background: linear-gradient(90deg, #9aa6b8 0%, #fff 30%, #9aa6b8 60%, #9aa6b8 100%); background-size: 200% 100%; -webkit-background-clip: text; background-clip: text; color: transparent; animation: shimmer 6s linear infinite; }
.scroll-cue { position: absolute; left: 50%; bottom: 30px; transform: translateX(-50%); color: var(--text-faint); font-family: var(--mono); font-size: .75rem; letter-spacing: .15em; text-transform: uppercase; display: flex; flex-direction: column; align-items: center; gap: 6px; }
.scroll-cue .ln { width: 1px; height: 36px; background: linear-gradient(180deg, transparent, var(--accent)); animation: blink 2s infinite; }
.cta-band { border: 1px solid var(--border-strong); background: radial-gradient(600px 200px at 10% 20%, rgba(93,200,255,.15), transparent 60%), radial-gradient(600px 200px at 90% 80%, rgba(125,108,255,.15), transparent 60%), var(--panel); border-radius: 22px; padding: 56px 40px; text-align: center; }

/* ================== RESPONSIVE ================== */
@media (max-width: 980px) {
    .hero-inner { grid-template-columns: 1fr; }
    .cols-3, .cols-4 { grid-template-columns: 1fr 1fr; }
    .feat-row, .feat-row.reverse { grid-template-columns: 1fr; direction: ltr; }
    .contact-grid, .legal-grid { grid-template-columns: 1fr; }
    .legal-toc { position: static; max-height: none; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .stats { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 720px) {
    .nav-links { display: none; }
    .nav-toggle { display: flex; margin-left: auto; }
    .nav-links.open { display: flex; flex-direction: column; align-items: stretch; position: absolute; top: 64px; left: 0; right: 0; background: var(--bg-2); padding: 14px; border-radius: 12px; border: 1px solid var(--border); }
    .cols-2, .cols-3, .cols-4 { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .hero-meta { grid-template-columns: 1fr 1fr; }
    section { padding: 70px 0; }
}

@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation-duration: .001s !important; transition-duration: .001s !important; } }