/* ---------- Design tokens ---------- */
:root {
  --bg: #f6f7fb;
  --bg-elev: #ffffff;
  --bg-elev-2: #eef0f7;
  --text: #12151c;
  --text-dim: #4a5265;
  --text-faint: #8890a0;
  --accent: #0f9d84;
  --accent-2: #0284c7;
  --accent-warm: #c2760a;
  --border: rgba(10,15,25,0.08);
  --border-strong: rgba(10,15,25,0.16);
  --shadow: 0 20px 60px rgba(20,25,40,0.10);
  --radius: 16px;
  --font-display: 'Space Grotesk', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
  color-scheme: light;
}

:root[data-theme="dark"] {
  --bg: #0a0e14;
  --bg-elev: #10151f;
  --bg-elev-2: #161d2b;
  --text: #eef1f6;
  --text-dim: #9aa4b6;
  --text-faint: #626d82;
  --accent: #5eead4;
  --accent-2: #7dd3fc;
  --accent-warm: #fbbf6b;
  --border: rgba(255,255,255,0.08);
  --border-strong: rgba(255,255,255,0.16);
  --shadow: 0 20px 60px rgba(0,0,0,0.45);
  color-scheme: dark;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-display);
  line-height: 1.5;
  overflow-x: hidden;
  transition: background 0.3s ease, color 0.3s ease;
}

::selection { background: var(--accent); color: #05221c; }

a { color: inherit; text-decoration: none; }

/* subtle grain */
.noise-overlay {
  position: fixed; inset: 0; pointer-events: none; z-index: 9999;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='100' height='100'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  mix-blend-mode: overlay;
}

.cursor-glow {
  position: fixed; width: 420px; height: 420px; border-radius: 50%;
  pointer-events: none; z-index: 0; top: 0; left: 0;
  background: radial-gradient(circle, rgba(94,234,212,0.10), transparent 70%);
  transform: translate(-50%, -50%);
  transition: opacity 0.3s ease;
  display: none;
}
@media (hover: hover) { .cursor-glow { display: block; } }

/* ---------- Nav ---------- */
#navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 6vw;
  backdrop-filter: blur(14px) saturate(140%);
  background: color-mix(in srgb, var(--bg) 70%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease;
}
#navbar.scrolled { border-bottom-color: var(--border); }

.nav-logo {
  font-weight: 700; font-size: 1.2rem; letter-spacing: 0.02em;
}
.nav-logo .dot { color: var(--accent); }

.nav-links {
  display: flex; align-items: center; gap: 2rem;
  font-size: 0.92rem; color: var(--text-dim);
}
.nav-links a { position: relative; padding: 4px 0; transition: color 0.2s; }
.nav-links a:hover { color: var(--text); }
.nav-links a::after {
  content: ''; position: absolute; left: 0; bottom: -2px; width: 0; height: 1.5px;
  background: var(--accent); transition: width 0.25s ease;
}
.nav-links a:hover::after { width: 100%; }

.theme-toggle {
  width: 36px; height: 36px; border-radius: 50%;
  border: 1px solid var(--border-strong); background: var(--bg-elev);
  color: var(--text); display: grid; place-items: center; cursor: pointer;
  transition: transform 0.3s ease, border-color 0.2s;
}
.theme-toggle:hover { border-color: var(--accent); transform: rotate(15deg); }
.icon-moon { display: none; }
:root[data-theme="dark"] .icon-sun { display: none; }
:root[data-theme="dark"] .icon-moon { display: block; }

.nav-toggle {
  display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 8px;
}
.nav-toggle span { width: 22px; height: 2px; background: var(--text); transition: 0.3s; }

/* ---------- Hero ---------- */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center; justify-content: center;
  padding: 120px 6vw 80px; overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; z-index: 0; }
#particleCanvas { width: 100%; height: 100%; display: block; opacity: 0.55; }

.hero-inner { position: relative; z-index: 2; max-width: 900px; text-align: center; margin: 0 auto; }

.eyebrow {
  font-family: var(--font-mono); font-size: 0.85rem; color: var(--accent);
  letter-spacing: 0.08em; text-transform: uppercase; margin-bottom: 1.2rem;
}

.hero h1 { display: flex; flex-direction: column; gap: 0.1em; margin-bottom: 1.2rem; }
.hero-name {
  font-size: clamp(2.2rem, 6vw, 4.2rem); font-weight: 700; line-height: 1.05; letter-spacing: -0.02em;
  background: linear-gradient(120deg, var(--text) 40%, var(--accent) 70%, var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

.hero-role {
  font-family: var(--font-mono); font-size: clamp(1rem, 2.2vw, 1.3rem); color: var(--text-dim);
  min-height: 1.6em; margin-bottom: 1.4rem;
}
.caret { color: var(--accent); animation: blink 1s step-end infinite; }
@keyframes blink { 50% { opacity: 0; } }

.hero-desc {
  max-width: 640px; margin: 0 auto 2.4rem; color: var(--text-dim); font-size: 1.05rem;
}
.hero-desc strong { color: var(--text); font-weight: 600; }

.hero-stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.4rem;
  max-width: 760px; margin: 0 auto 2.6rem; padding: 1.6rem;
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
}
.stat { display: flex; flex-direction: column; gap: 0.3rem; }
.stat-num { font-family: var(--font-mono); font-size: 1.7rem; font-weight: 700; color: var(--accent); }
.stat-label { font-size: 0.74rem; color: var(--text-faint); line-height: 1.3; }

.hero-cta { display: flex; flex-wrap: wrap; gap: 0.9rem; justify-content: center; margin-bottom: 1.8rem; }
.btn {
  padding: 0.8rem 1.6rem; border-radius: 999px; font-size: 0.92rem; font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
  display: inline-flex; align-items: center; gap: 0.4rem; cursor: pointer;
}
.btn-primary { background: var(--accent); color: #052420; border: 1px solid var(--accent); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 30px rgba(94,234,212,0.25); }
.btn-outline { border: 1px solid var(--border-strong); color: var(--text); }
.btn-outline:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }
.btn-ghost { color: var(--text-dim); }
.btn-ghost:hover { color: var(--text); }

.hero-links { display: flex; gap: 1.6rem; justify-content: center; font-size: 0.88rem; color: var(--text-faint); }
.hero-links a:hover { color: var(--accent); }

.scroll-cue {
  position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%); z-index: 2;
  width: 26px; height: 42px; border: 1.5px solid var(--border-strong); border-radius: 20px;
}
.scroll-cue span {
  position: absolute; top: 8px; left: 50%; width: 4px; height: 8px; border-radius: 2px;
  background: var(--accent); transform: translateX(-50%);
  animation: scrollcue 1.8s ease-in-out infinite;
}
@keyframes scrollcue { 0%{opacity:1;top:8px;} 70%{opacity:0;top:22px;} 100%{opacity:0;top:8px;} }

/* ---------- Sections ---------- */
.section { padding: 7rem 6vw; position: relative; }
.section-inner { max-width: 1080px; margin: 0 auto; }
.section-tag {
  font-family: var(--font-mono); font-size: 0.8rem; color: var(--accent);
  letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 0.8rem;
}
.section-tag.small { margin-bottom: 0.6rem; }
.section h2 { font-size: clamp(1.8rem, 3.6vw, 2.6rem); font-weight: 700; letter-spacing: -0.02em; margin-bottom: 1.8rem; }

.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in-view { opacity: 1; transform: translateY(0); }

/* About */
.about-body { max-width: 720px; color: var(--text-dim); font-size: 1.05rem; margin-bottom: 2.4rem; }
.about-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.2rem; }
.about-card {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.6rem; transition: transform 0.25s ease, border-color 0.25s ease;
}
.about-card:hover { transform: translateY(-4px); border-color: var(--accent); }
.about-card h3 { font-size: 1.02rem; margin-bottom: 0.5rem; color: var(--accent); }
.about-card p { color: var(--text-dim); font-size: 0.92rem; }

/* Skills */
.skill-filters { display: flex; gap: 0.6rem; flex-wrap: wrap; margin-bottom: 1.8rem; }
.filter-btn {
  padding: 0.5rem 1.1rem; border-radius: 999px; border: 1px solid var(--border-strong);
  background: transparent; color: var(--text-dim); font-family: var(--font-mono); font-size: 0.82rem;
  cursor: pointer; transition: all 0.2s ease;
}
.filter-btn:hover { border-color: var(--accent); color: var(--text); }
.filter-btn.active { background: var(--accent); color: #052420; border-color: var(--accent); }

.skill-cloud { display: flex; flex-wrap: wrap; gap: 0.7rem; }
.skill-tag {
  padding: 0.55rem 1.1rem; border-radius: 10px; background: var(--bg-elev);
  border: 1px solid var(--border); font-size: 0.9rem; color: var(--text);
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
  cursor: default;
}
.skill-tag:hover { transform: translateY(-3px) scale(1.04); border-color: var(--accent); background: var(--bg-elev-2); }
.skill-tag.hidden { display: none; }

/* Projects */
.project-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.4rem; }
.project-card {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.8rem; transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
  display: flex; flex-direction: column;
}
.project-card:hover { transform: translateY(-6px); border-color: var(--accent); box-shadow: var(--shadow); }
.project-card-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.project-icon { font-size: 1.6rem; }
.project-link {
  width: 34px; height: 34px; border-radius: 50%; border: 1px solid var(--border-strong);
  display: grid; place-items: center; font-size: 1rem; transition: all 0.2s ease;
}
.project-link:hover { background: var(--accent); color: #052420; border-color: var(--accent); transform: rotate(45deg); }
.project-link-static { cursor: default; font-size: 0.85rem; opacity: 0.6; }
.project-link-static:hover { background: none; color: inherit; border-color: var(--border-strong); transform: none; }
.project-card h3 { font-size: 1.12rem; margin-bottom: 0.7rem; }
.project-card p { color: var(--text-dim); font-size: 0.92rem; flex-grow: 1; margin-bottom: 1.1rem; }
.project-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; list-style: none; }
.project-tags li {
  font-family: var(--font-mono); font-size: 0.74rem; padding: 0.3rem 0.7rem; border-radius: 6px;
  background: var(--bg-elev-2); color: var(--accent-2);
}

/* Thesis */
.thesis-section { background: var(--bg-elev); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.thesis-sub { font-family: var(--font-mono); color: var(--text-faint); font-size: 0.88rem; margin-bottom: 1.4rem; }
.thesis-desc { max-width: 740px; color: var(--text-dim); font-size: 1.05rem; margin-bottom: 2.6rem; }

.thesis-flow {
  display: flex; align-items: center; justify-content: center; gap: 1.6rem; flex-wrap: wrap;
  margin-bottom: 2.8rem;
}
.flow-step {
  display: flex; flex-direction: column; align-items: center; gap: 0.4rem;
  padding: 1.4rem 2.2rem; border-radius: var(--radius); border: 1px solid var(--border);
  background: var(--bg-elev-2); min-width: 200px;
}
.flow-step.highlight { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent) inset; }
.flow-time { font-family: var(--font-mono); font-size: 1.7rem; font-weight: 700; }
.flow-step.highlight .flow-time { color: var(--accent); }
.flow-label { font-size: 0.82rem; color: var(--text-dim); text-align: center; }
.flow-arrow { font-size: 1.6rem; color: var(--text-faint); }

.thesis-gallery { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.4rem; margin-bottom: 3rem; }
.thesis-figure {
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; transition: transform 0.25s ease, border-color 0.25s ease;
}
.thesis-figure:hover { transform: translateY(-4px); border-color: var(--accent-2); }
.thesis-figure img { width: 100%; height: 200px; object-fit: contain; background: #ffffff; display: block; }
.thesis-figure figcaption { padding: 0.9rem 1.1rem; font-size: 0.8rem; color: var(--text-dim); border-top: 1px solid var(--border); }

.thesis-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.2rem; margin-bottom: 3rem; }
.thesis-card {
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.6rem;
  transition: transform 0.25s ease, border-color 0.25s ease;
}
.thesis-card:hover { transform: translateY(-4px); border-color: var(--accent-2); }
.thesis-card h3 { color: var(--accent-2); font-size: 1rem; margin-bottom: 0.5rem; }
.thesis-card p { color: var(--text-dim); font-size: 0.9rem; }

.thesis-result { max-width: 640px; }
.result-bar-wrap { margin-bottom: 1.2rem; }
.result-label { font-size: 0.85rem; color: var(--text-dim); display: block; margin-bottom: 0.5rem; }
.result-bar { background: var(--bg); border: 1px solid var(--border); border-radius: 8px; height: 34px; overflow: hidden; }
.result-bar-fill {
  height: 100%; width: 0%; background: var(--accent-warm); border-radius: 8px;
  display: flex; align-items: center; justify-content: flex-end; padding-right: 10px;
  font-family: var(--font-mono); font-size: 0.78rem; color: #241300; font-weight: 600;
  transition: width 1.4s cubic-bezier(0.16, 1, 0.3, 1);
}
.result-bar-fill.result-bar-good { background: var(--accent); color: #052420; }
.result-bar-wrap.in-view .result-bar-fill { width: var(--pct); }
.result-caption { font-size: 0.85rem; color: var(--text-faint); margin-top: 0.4rem; }

/* Timeline */
.timeline { position: relative; padding-left: 2rem; margin-bottom: 3.5rem; }
.timeline::before {
  content: ''; position: absolute; left: 5px; top: 6px; bottom: 6px; width: 2px;
  background: linear-gradient(var(--border-strong), transparent);
}
.timeline-item { position: relative; padding-bottom: 2.4rem; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot {
  position: absolute; left: -2rem; top: 4px; width: 12px; height: 12px; border-radius: 50%;
  background: var(--bg); border: 2px solid var(--accent);
}
.timeline-date { font-family: var(--font-mono); font-size: 0.78rem; color: var(--accent); }
.timeline-content h3 { font-size: 1.05rem; margin: 0.3rem 0 0.5rem; }
.timeline-content p { color: var(--text-dim); font-size: 0.92rem; max-width: 680px; }

.edu-cert-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.6rem; }
.edu-block, .cert-block {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.6rem;
}
.edu-block h3 { font-size: 0.98rem; margin: 0.6rem 0 0.15rem; }
.edu-block h3:first-of-type { margin-top: 0.4rem; }
.muted { color: var(--text-faint); font-size: 0.85rem; }
.cert-list { list-style: none; display: flex; flex-direction: column; gap: 0.6rem; margin-top: 0.4rem; }
.cert-list li { font-size: 0.9rem; color: var(--text-dim); padding-left: 1.1rem; position: relative; }
.cert-list li::before { content: '✓'; position: absolute; left: 0; color: var(--accent); }

/* Contact */
.contact-section { text-align: center; }
.contact-desc { color: var(--text-dim); margin-bottom: 2.2rem; }
.contact-links { display: flex; flex-wrap: wrap; gap: 0.8rem; justify-content: center; }
.contact-pill {
  padding: 0.75rem 1.4rem; border-radius: 999px; border: 1px solid var(--border-strong);
  font-family: var(--font-mono); font-size: 0.85rem; transition: all 0.2s ease;
}
.contact-pill:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-3px); }

footer { text-align: center; padding: 2.4rem; color: var(--text-faint); font-size: 0.8rem; border-top: 1px solid var(--border); }

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .project-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 860px) {
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .about-grid, .thesis-grid, .thesis-gallery { grid-template-columns: 1fr; }
  .edu-cert-grid { grid-template-columns: 1fr; }
  .thesis-flow { flex-direction: column; }
  .flow-arrow { transform: rotate(90deg); }
}

@media (max-width: 560px) {
  .project-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .nav-links {
    position: fixed; top: 64px; right: 0; height: calc(100vh - 64px); width: 78%;
    background: var(--bg-elev); flex-direction: column; align-items: flex-start; padding: 2rem;
    border-left: 1px solid var(--border); transform: translateX(100%); transition: transform 0.3s ease;
    gap: 1.6rem; font-size: 1.05rem;
  }
  .nav-links.open { transform: translateX(0); }
  .nav-toggle { display: flex; }
  .theme-toggle { margin-top: 1rem; }
  .hero-stats { grid-template-columns: 1fr 1fr; padding: 1.1rem; gap: 1rem; }
  .section { padding: 5rem 6vw; }
}