:root {
    --bg: #050a15;
    --bg-card: #091221;
    --bg-card-2: #0c1829;
    --border: rgba(0, 212, 255, 0.12);
    --border-bright: rgba(0, 212, 255, 0.35);
    --primary: #00d4ff;
    --primary-dim: rgba(0, 212, 255, 0.1);
    --primary-glow: rgba(0, 212, 255, 0.4);
    --violet: #818cf8;
    --violet-dim: rgba(129, 140, 248, 0.1);
    --green: #34d399;
    --green-dim: rgba(52, 211, 153, 0.1);
    --orange: #fbbf24;
    --orange-dim: rgba(251, 191, 36, 0.1);
    --text: #e2e8f0;
    --text-subtle: #94a3b8;
    --text-muted: #475569;
    --radius: 12px;
    --radius-lg: 20px;
    --trans: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    background-color: var(--bg);
    color: var(--text);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
}
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--primary); border-radius: 2px; }

/* NAV */
nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    padding: 0 48px; height: 64px;
    display: flex; align-items: center; justify-content: space-between;
    transition: var(--trans);
}
nav.scrolled {
    background: rgba(5, 10, 21, 0.93);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
}
.nav-logo {
    font-family: 'JetBrains Mono', monospace;
    font-size: 20px; font-weight: 600; color: var(--primary);
    letter-spacing: 3px; text-shadow: 0 0 20px var(--primary-glow);
}
.nav-links { display: flex; list-style: none; gap: 4px; }
.nav-links a {
    color: var(--text-subtle); text-decoration: none;
    font-size: 13px; font-weight: 500;
    padding: 6px 14px; border-radius: 20px; transition: var(--trans);
}
.nav-links a:hover, .nav-links a.active {
    color: var(--primary); background: var(--primary-dim);
}

/* SECTIONS */
section { padding: 100px 48px; }
.container { max-width: 1100px; margin: 0 auto; }
.section-header { text-align: center; margin-bottom: 60px; }
.section-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px; font-weight: 500; color: var(--primary);
    letter-spacing: 3px; text-transform: uppercase; margin-bottom: 12px;
}
.section-title { font-size: clamp(26px, 4vw, 38px); font-weight: 700; color: var(--text); }
.section-title span { color: var(--primary); }
.section-divider {
    width: 60px; height: 3px;
    background: linear-gradient(90deg, var(--primary), transparent);
    margin: 16px auto 0; border-radius: 2px;
}

/* HERO */
#home {
    position: relative; height: 100vh; min-height: 680px;
    padding: 0; display: flex; align-items: center; justify-content: center; overflow: hidden;
}
#particles-canvas { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }
.hero-grid-overlay {
    position: absolute; inset: 0;
    background-image:
        linear-gradient(rgba(0,212,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,212,255,0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black, transparent);
}
.hero-content { position: relative; z-index: 10; text-align: center; padding: 0 20px; }
.hero-badge {
    display: inline-block;
    background: var(--primary-dim); border: 1px solid var(--border-bright);
    color: var(--primary); font-family: 'JetBrains Mono', monospace;
    font-size: 11px; letter-spacing: 3px; padding: 6px 20px; border-radius: 20px;
    margin-bottom: 28px; animation: fadeInDown 0.8s ease both;
}
.hero-name {
    font-size: clamp(56px, 9vw, 100px); font-weight: 700;
    letter-spacing: -3px; color: #fff; line-height: 1; margin-bottom: 20px;
    animation: fadeInUp 0.8s ease 0.1s both;
}
.hero-name .glow {
    color: var(--primary);
    text-shadow: 0 0 60px var(--primary-glow), 0 0 120px rgba(0,212,255,0.15);
}
.hero-title {
    font-size: clamp(15px, 2.2vw, 20px); color: var(--text-subtle);
    margin-bottom: 52px; min-height: 1.6em; animation: fadeInUp 0.8s ease 0.2s both;
}
#typewriter { border-right: 2px solid var(--primary); padding-right: 2px; }
.hero-stats {
    display: flex; justify-content: center; gap: 56px; margin-bottom: 52px;
    flex-wrap: wrap; animation: fadeInUp 0.8s ease 0.3s both;
}
.stat-item { text-align: center; }
.stat-number {
    font-size: 38px; font-weight: 700; color: var(--primary);
    font-family: 'JetBrains Mono', monospace; line-height: 1; display: inline;
    text-shadow: 0 0 24px var(--primary-glow);
}
.stat-suffix { font-size: 16px; color: var(--primary); font-weight: 600; }
.stat-label { font-size: 11px; color: var(--text-muted); margin-top: 6px; letter-spacing: 1px; display: block; }
.hero-cta { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; animation: fadeInUp 0.8s ease 0.4s both; }
.btn-outline {
    border: 1px solid var(--border-bright); color: var(--primary);
    text-decoration: none; padding: 13px 32px; border-radius: 8px;
    font-weight: 500; font-size: 14px; transition: var(--trans);
}
.btn-outline:hover { background: var(--primary-dim); transform: translateY(-2px); }
.scroll-indicator {
    position: absolute; bottom: 36px; left: 50%; transform: translateX(-50%);
    display: flex; flex-direction: column; align-items: center; gap: 8px;
    animation: bounce 2.5s ease infinite;
}
.scroll-indicator span { font-size: 10px; color: var(--text-muted); letter-spacing: 3px; }
.scroll-dot { width: 1px; height: 44px; background: linear-gradient(to bottom, var(--primary), transparent); }

/* ABOUT */
#about { background: linear-gradient(180deg, var(--bg), #07101f); }
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: start; }
.about-text p { color: var(--text-subtle); margin-bottom: 16px; font-size: 15px; line-height: 1.9; }
.about-text p strong { color: var(--primary); font-weight: 600; }
.about-highlights { display: flex; flex-direction: column; gap: 14px; }
.highlight-card {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 18px 22px; display: flex; align-items: flex-start; gap: 14px; transition: var(--trans);
}
.highlight-card:hover { border-color: var(--border-bright); background: var(--bg-card-2); transform: translateX(5px); }
.highlight-icon { font-size: 24px; flex-shrink: 0; line-height: 1.3; }
.highlight-info h4 { font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 3px; }
.highlight-info p { font-size: 12px; color: var(--text-subtle); line-height: 1.6; }

/* SKILLS */
#skills { background: #06101f; }
.skills-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.skill-category {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 24px; transition: var(--trans);
}
.skill-category:hover { border-color: var(--border-bright); }
.skill-cat-header { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.skill-cat-icon { font-size: 20px; }
.skill-cat-name { font-size: 13px; font-weight: 600; color: var(--text); }
.skill-tags { display: flex; flex-wrap: wrap; gap: 7px; }
.tag {
    font-family: 'JetBrains Mono', monospace; font-size: 11px;
    padding: 4px 10px; border-radius: 4px; border: 1px solid; white-space: nowrap;
}
.tag-cyan   { color: var(--primary); background: var(--primary-dim); border-color: rgba(0,212,255,0.25); }
.tag-violet { color: var(--violet);  background: var(--violet-dim);  border-color: rgba(129,140,248,0.25); }
.tag-green  { color: var(--green);   background: var(--green-dim);   border-color: rgba(52,211,153,0.25); }
.tag-orange { color: var(--orange);  background: var(--orange-dim);  border-color: rgba(251,191,36,0.25); }
.tag-pink   { color: #f472b6; background: rgba(244,114,182,0.08); border-color: rgba(244,114,182,0.25); }
.tag-red    { color: #f87171; background: rgba(248,113,113,0.08); border-color: rgba(248,113,113,0.25); }

/* EXPERIENCE */
#experience { background: linear-gradient(180deg, #06101f, var(--bg)); }
.timeline { position: relative; padding-left: 40px; }
.timeline::before {
    content: ''; position: absolute; left: 0; top: 8px; bottom: 8px; width: 1px;
    background: linear-gradient(to bottom, var(--primary), rgba(0,212,255,0.05));
}
.timeline-item { position: relative; margin-bottom: 40px; }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-dot {
    position: absolute; left: -46px; top: 6px;
    width: 12px; height: 12px; border-radius: 50%;
    background: var(--primary); box-shadow: 0 0 14px var(--primary-glow); border: 2px solid var(--bg);
}
.timeline-card {
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 26px 30px; transition: var(--trans);
}
.timeline-card:hover { border-color: var(--border-bright); }
.timeline-header {
    display: flex; justify-content: space-between; align-items: flex-start;
    flex-wrap: wrap; gap: 10px; margin-bottom: 6px;
}
.timeline-company { font-size: 16px; font-weight: 700; color: var(--text); }
.timeline-period {
    font-family: 'JetBrains Mono', monospace; font-size: 11px; color: var(--primary);
    background: var(--primary-dim); padding: 4px 12px; border-radius: 20px; white-space: nowrap;
}
.timeline-role { font-size: 13px; color: var(--green); margin-bottom: 14px; font-weight: 500; }
.timeline-list { list-style: none; }
.timeline-list li {
    font-size: 13px; color: var(--text-subtle); padding: 3px 0 3px 18px;
    position: relative; line-height: 1.7;
}
.timeline-list li::before { content: '›'; position: absolute; left: 0; color: var(--primary); font-size: 18px; line-height: 1.35; }
.timeline-achievement { margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--border); }
.ach-label {
    font-size: 10px; font-family: 'JetBrains Mono', monospace; color: var(--orange);
    letter-spacing: 2px; text-transform: uppercase; margin-bottom: 8px;
}
.timeline-achievement .timeline-list li::before { color: var(--orange); }

/* CERTIFICATES */
#certificates { background: #06101f; }
.certs-main-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; max-width: 840px; margin: 0 auto 24px; }
.cert-card {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-lg);
    overflow: hidden; transition: var(--trans); cursor: pointer;
}
.cert-card:hover { border-color: var(--border-bright); transform: translateY(-5px); box-shadow: 0 20px 48px rgba(0,0,0,0.4); }
.cert-image-wrapper { width: 100%; aspect-ratio: 4/3; overflow: hidden; }
.cert-image-wrapper img { width: 100%; height: 100%; object-fit: cover; transition: var(--trans); }
.cert-card:hover .cert-image-wrapper img { transform: scale(1.04); }
.cert-info { padding: 18px 20px; }
.cert-name { font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 4px; }
.cert-detail { font-size: 11px; color: var(--text-subtle); font-family: 'JetBrains Mono', monospace; }
.cert-badge { display: inline-block; margin-top: 10px; font-size: 11px; padding: 3px 12px; border-radius: 12px; }
.badge-gold { background: var(--orange-dim); color: var(--orange); border: 1px solid rgba(251,191,36,0.3); }
.badge-cyan { background: var(--primary-dim); color: var(--primary); border: 1px solid rgba(0,212,255,0.3); }
.certs-other { display: flex; gap: 14px; max-width: 840px; margin: 0 auto; flex-wrap: wrap; }
.cert-other-item {
    flex: 1; min-width: 180px; background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 16px 20px; display: flex; align-items: center; gap: 12px;
}
.cert-other-icon {
    width: 36px; height: 36px; border-radius: 8px; background: var(--primary-dim);
    display: flex; align-items: center; justify-content: center; font-size: 17px; flex-shrink: 0;
}
.cert-other-name { font-size: 13px; font-weight: 600; color: var(--text); }
.cert-other-sub { font-size: 11px; color: var(--text-subtle); }

/* LIGHTBOX */
.lightbox {
    display: none; position: fixed; inset: 0; z-index: 9999;
    background: rgba(0,0,0,0.93); align-items: center; justify-content: center; padding: 20px;
}
.lightbox.active { display: flex; }
.lightbox img { max-width: 90vw; max-height: 90vh; border-radius: var(--radius); box-shadow: 0 0 80px rgba(0,212,255,0.2); }
.lightbox-close {
    position: absolute; top: 20px; right: 28px; color: var(--text-subtle);
    font-size: 36px; cursor: pointer; line-height: 1; transition: var(--trans);
}
.lightbox-close:hover { color: var(--primary); }

/* EDUCATION */
#education { background: linear-gradient(180deg, var(--bg), #07101f); }
.edu-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; max-width: 760px; margin: 0 auto; }
.edu-card {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 28px; transition: var(--trans);
}
.edu-card:hover { border-color: var(--border-bright); }
.edu-school { font-size: 17px; font-weight: 700; color: var(--text); margin-bottom: 6px; }
.edu-degree { font-size: 13px; color: var(--primary); margin-bottom: 3px; }
.edu-major { font-size: 13px; color: var(--text-subtle); margin-bottom: 10px; }
.edu-period { font-family: 'JetBrains Mono', monospace; font-size: 12px; color: var(--text-muted); }
.edu-note { font-size: 12px; color: var(--green); margin-top: 6px; }

/* CONTACT */
#contact { background: var(--bg); text-align: center; }
.contact-wrapper { max-width: 520px; margin: 0 auto; }
.contact-intro { font-size: 15px; color: var(--text-subtle); margin-bottom: 44px; line-height: 1.8; }
.contact-items { display: flex; flex-direction: column; gap: 14px; }
.contact-item {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 18px 26px; display: flex; align-items: center; gap: 16px;
    text-decoration: none; transition: var(--trans);
}
.contact-item:hover { border-color: var(--border-bright); background: var(--bg-card-2); }
.contact-icon {
    width: 44px; height: 44px; border-radius: 10px; background: var(--primary-dim);
    display: flex; align-items: center; justify-content: center; font-size: 20px; flex-shrink: 0;
}
.contact-label { font-size: 10px; color: var(--text-muted); letter-spacing: 2px; font-family: 'JetBrains Mono', monospace; }
.contact-value { font-size: 14px; color: var(--text); font-weight: 500; text-align: left; }

/* FOOTER */
footer { background: #020710; border-top: 1px solid var(--border); padding: 24px 48px; text-align: center; }
footer p { font-size: 12px; color: var(--text-muted); font-family: 'JetBrains Mono', monospace; }
footer span { color: var(--primary); }

/* ANIMATIONS */
@keyframes fadeInDown { from { opacity: 0; transform: translateY(-20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes fadeInUp   { from { opacity: 0; transform: translateY(30px);  } to { opacity: 1; transform: translateY(0); } }
@keyframes bounce     { 0%, 100% { transform: translateX(-50%) translateY(0); } 50% { transform: translateX(-50%) translateY(10px); } }
.reveal { opacity: 0; transform: translateY(36px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* RESPONSIVE */
@media (max-width: 900px) {
    nav { padding: 0 20px; }
    .nav-links { display: none; }
    section { padding: 80px 20px; }
    .about-grid { grid-template-columns: 1fr; gap: 40px; }
    .skills-grid { grid-template-columns: 1fr 1fr; }
    .hero-stats { gap: 28px; }
}
@media (max-width: 600px) {
    .skills-grid { grid-template-columns: 1fr; }
    .certs-main-grid { grid-template-columns: 1fr; }
    .edu-grid { grid-template-columns: 1fr; }
}