/* ============================================
   NECHIRVAN OTHMAN — Personal Academic Website
   Design: Dark editorial / refined academic
   ============================================ */

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

:root {
  --bg: #0d0f14;
  --bg2: #13161e;
  --bg3: #1a1e28;
  --surface: #1f2433;
  --border: rgba(255,255,255,0.07);
  --border-hover: rgba(255,255,255,0.15);
  --text: #e8e4dc;
  --text-muted: #8a8a9a;
  --text-dim: #5a5a6a;
  --accent: #c8964a;
  --accent-soft: rgba(200,150,74,0.12);
  --accent-glow: rgba(200,150,74,0.25);
  --blue: #4a90c8;
  --teal: #4ac8b4;
  --serif: 'Cormorant Garamond', Georgia, serif;
  --mono: 'JetBrains Mono', 'Courier New', monospace;
  --sans: 'Outfit', system-ui, sans-serif;
  --radius: 8px;
  --radius-lg: 14px;
  --nav-h: 70px;
  --max: 1180px;
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; scroll-padding-top: var(--nav-h); }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  font-weight: 300;
  overflow-x: hidden;
}

::selection { background: var(--accent-soft); color: var(--accent); }

/* ---- UTILITY ---- */
.mono { font-family: var(--mono); font-size: 0.78rem; letter-spacing: 0.04em; }
.accent { color: var(--accent); }
.container { max-width: var(--max); margin: 0 auto; padding: 0 2rem; }
.lead { font-size: 1.15rem; line-height: 1.75; color: var(--text); font-weight: 300; }

/* ---- NAV ---- */
#navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(13,15,20,0.0);
  backdrop-filter: blur(0px);
  border-bottom: 1px solid transparent;
  transition: background 0.4s var(--ease), backdrop-filter 0.4s, border-color 0.4s;
}
#navbar.scrolled {
  background: rgba(13,15,20,0.92);
  backdrop-filter: blur(20px);
  border-bottom-color: var(--border);
}
.nav-inner {
  max-width: var(--max); margin: 0 auto; padding: 0 2rem;
  height: 100%; display: flex; align-items: center; justify-content: space-between;
}
.nav-logo {
  font-family: var(--serif); font-size: 1.5rem; font-weight: 600;
  color: var(--text); text-decoration: none; letter-spacing: 0.02em;
}
.nav-links {
  list-style: none; display: flex; align-items: center; gap: 0.25rem;
}
.nav-links a {
  color: var(--text-muted); text-decoration: none;
  padding: 0.4rem 0.9rem; border-radius: var(--radius);
  font-size: 0.875rem; font-weight: 400; letter-spacing: 0.01em;
  transition: color 0.2s, background 0.2s;
}
.nav-links a:hover { color: var(--text); background: rgba(255,255,255,0.05); }
.nav-links .nav-cta {
  background: var(--accent-soft); color: var(--accent);
  border: 1px solid rgba(200,150,74,0.3);
  margin-left: 0.5rem;
}
.nav-links .nav-cta:hover { background: var(--accent); color: var(--bg); }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 4px; flex-direction: column; gap: 5px; }
.nav-toggle span { display: block; width: 22px; height: 1.5px; background: var(--text); transition: all 0.3s; }

/* ---- HERO ---- */
.hero {
  min-height: 100vh; display: flex; flex-direction: column;
  justify-content: center; position: relative; overflow: hidden;
  padding: calc(var(--nav-h) + 4rem) 0 4rem;
}
.hero-bg { position: absolute; inset: 0; z-index: 0; }
.hero-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, black 0%, transparent 100%);
}
.orb {
  position: absolute; border-radius: 50%; filter: blur(80px); pointer-events: none;
}
.orb-1 { width: 500px; height: 500px; background: rgba(200,150,74,0.07); top: -100px; right: -100px; }
.orb-2 { width: 400px; height: 400px; background: rgba(74,144,200,0.05); bottom: 0; left: -150px; }
.hero-inner {
  position: relative; z-index: 1;
  max-width: var(--max); margin: 0 auto; padding: 0 2rem;
  display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; align-items: center;
}
.hero-tag { color: var(--accent); display: block; margin-bottom: 1.5rem; }
.hero-name {
  font-family: var(--serif); font-size: clamp(3rem, 6vw, 5.5rem);
  font-weight: 300; line-height: 1.05; color: var(--text);
  margin-bottom: 1.5rem; letter-spacing: -0.01em;
}
.hero-name em { color: var(--accent); font-style: italic; font-weight: 300; }
.hero-desc { color: var(--text-muted); font-size: 1.05rem; max-width: 480px; margin-bottom: 2.5rem; }
.hero-actions { display: flex; gap: 1rem; margin-bottom: 2rem; flex-wrap: wrap; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.tag {
  font-size: 0.72rem; font-family: var(--mono);
  color: var(--text-muted); background: rgba(255,255,255,0.04);
  border: 1px solid var(--border); border-radius: 4px;
  padding: 3px 10px; letter-spacing: 0.04em;
}

/* Hero photo */
.hero-photo-wrap { display: flex; flex-direction: column; align-items: flex-end; gap: 1.5rem; }
.photo-frame {
  position: relative; width: 280px; height: 320px;
  border-radius: var(--radius-lg); overflow: visible;
}
.hero-photo {
  width: 100%; height: 100%; object-fit: cover; object-position: top center;
  border-radius: var(--radius-lg);
  filter: grayscale(15%) contrast(1.05);
  position: relative; z-index: 1;
  box-shadow: 0 30px 80px rgba(0,0,0,0.6);
}
.photo-deco {
  position: absolute; inset: -8px; border-radius: calc(var(--radius-lg) + 4px);
  border: 1px solid rgba(200,150,74,0.3);
  background: linear-gradient(135deg, rgba(200,150,74,0.1) 0%, transparent 60%);
  z-index: 0;
}
.hero-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 1rem 1.25rem;
  width: 260px; align-self: flex-end;
}
.card-label { color: var(--text-dim); display: block; margin-bottom: 2px; font-size: 0.7rem; }
.hero-card p { font-size: 0.85rem; color: var(--text); font-weight: 400; line-height: 1.4; }

/* Scroll hint */
.scroll-hint {
  position: absolute; bottom: 2rem; left: 50%; transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  color: var(--text-dim); text-decoration: none; z-index: 1;
  animation: float 2.5s ease-in-out infinite;
}
.scroll-line {
  width: 1px; height: 40px; background: linear-gradient(to bottom, var(--text-dim), transparent);
}
@keyframes float { 0%,100%{transform:translateX(-50%) translateY(0)} 50%{transform:translateX(-50%) translateY(6px)} }

/* ---- BUTTONS ---- */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.65rem 1.6rem; border-radius: var(--radius);
  font-size: 0.875rem; font-weight: 400; font-family: var(--sans);
  text-decoration: none; border: none; cursor: pointer;
  transition: all 0.2s var(--ease); letter-spacing: 0.02em;
}
.btn-primary { background: var(--accent); color: #0d0f14; font-weight: 500; }
.btn-primary:hover { background: #d8a85a; transform: translateY(-1px); box-shadow: 0 8px 30px var(--accent-glow); }
.btn-ghost { background: transparent; color: var(--text); border: 1px solid var(--border-hover); }
.btn-ghost:hover { background: rgba(255,255,255,0.05); border-color: var(--text-muted); }
.full-width { width: 100%; justify-content: center; }

/* ---- SECTIONS ---- */
.section { padding: 7rem 0; }
.dark-section { background: var(--bg2); }
.section-header { margin-bottom: 3.5rem; }
.section-num { color: var(--accent); font-size: 0.72rem; display: block; margin-bottom: 0.5rem; letter-spacing: 0.1em; }
.section-header h2 {
  font-family: var(--serif); font-size: clamp(2.2rem, 4vw, 3rem);
  font-weight: 300; color: var(--text); letter-spacing: -0.01em;
}
.section-subtitle { color: var(--text-muted); margin-top: 0.75rem; max-width: 550px; }

/* ---- ABOUT ---- */
.about-grid { display: grid; grid-template-columns: 1fr 380px; gap: 4rem; align-items: start; }
.about-text p { color: var(--text-muted); margin-bottom: 1.25rem; }
.about-text .lead { color: var(--text); }
.about-stats { display: flex; gap: 2.5rem; margin-top: 2.5rem; padding-top: 2rem; border-top: 1px solid var(--border); }
.stat-num { font-family: var(--serif); font-size: 2.5rem; color: var(--accent); display: block; line-height: 1; }
.stat-label { color: var(--text-dim); font-size: 0.7rem; margin-top: 4px; display: block; }
.sidebar-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 1.5rem; margin-bottom: 1.25rem;
}
.sidebar-card h4 { color: var(--accent); font-size: 0.7rem; margin-bottom: 1rem; letter-spacing: 0.1em; }
.edu-item { display: flex; gap: 1rem; margin-bottom: 1rem; padding-bottom: 1rem; border-bottom: 1px solid var(--border); }
.edu-item:last-child { margin-bottom: 0; padding-bottom: 0; border-bottom: none; }
.edu-year { color: var(--text-dim); font-size: 0.65rem; min-width: 60px; padding-top: 3px; white-space: nowrap; }
.edu-item strong { display: block; font-weight: 500; font-size: 0.875rem; color: var(--text); line-height: 1.4; }
.edu-item span { font-size: 0.78rem; color: var(--text-muted); }
.lang-row { display: flex; justify-content: space-between; padding: 0.4rem 0; border-bottom: 1px solid var(--border); font-size: 0.875rem; }
.lang-row:last-child { border-bottom: none; }

/* ---- RESEARCH ---- */
.research-hero { margin-bottom: 3rem; max-width: 820px; }
.research-label { color: var(--accent); font-size: 0.7rem; display: block; margin-bottom: 1rem; letter-spacing: 0.1em; }
.research-title {
  font-family: var(--serif); font-size: clamp(1.4rem, 2.5vw, 1.9rem);
  font-weight: 300; color: var(--text); line-height: 1.4;
  margin-bottom: 1.25rem; font-style: italic;
}
.research-summary { color: var(--text-muted); font-size: 1rem; line-height: 1.8; }
.research-pillars { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.25rem; margin-bottom: 3rem; }
.pillar {
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 1.5rem;
  transition: border-color 0.3s, transform 0.3s;
}
.pillar:hover { border-color: var(--accent-glow); transform: translateY(-4px); }
.pillar-icon { color: var(--accent); font-size: 1.3rem; display: block; margin-bottom: 0.75rem; }
.pillar h4 { font-weight: 500; font-size: 0.9rem; margin-bottom: 0.5rem; color: var(--text); }
.pillar p { font-size: 0.82rem; color: var(--text-muted); line-height: 1.6; }
.recent-paper {
  background: var(--bg3); border: 1px solid var(--border);
  border-left: 3px solid var(--accent); border-radius: var(--radius-lg);
  padding: 2rem; max-width: 720px;
}
.recent-paper h4 { font-weight: 500; font-size: 1rem; color: var(--text); margin: 0.5rem 0 0.75rem; line-height: 1.5; }
.recent-paper p { font-size: 0.875rem; color: var(--text-muted); line-height: 1.7; margin-bottom: 1rem; }
.paper-meta { display: flex; gap: 2rem; color: var(--text-dim); font-size: 0.7rem; }

/* ---- TIMELINE ---- */
.timeline { position: relative; padding-left: 1.5rem; }
.timeline::before { content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 1px; background: var(--border); }
.tl-item {
  position: relative; padding: 0 0 2.5rem 2rem; margin-left: 0;
}
.tl-item::before {
  content: ''; position: absolute; left: -5px; top: 6px;
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--bg); border: 2px solid var(--accent);
  transition: background 0.3s;
}
.tl-item:hover::before { background: var(--accent); }
.tl-item:last-child { padding-bottom: 0; }
.tl-meta { display: flex; align-items: center; gap: 1rem; margin-bottom: 0.5rem; }
.tl-date { color: var(--text-dim); font-size: 0.7rem; }
.tl-type { font-size: 0.65rem; padding: 2px 8px; border-radius: 3px; }
.tl-content h4 { font-weight: 500; font-size: 1rem; color: var(--text); margin-bottom: 0.2rem; }
.tl-org { font-size: 0.8rem; color: var(--accent); font-family: var(--mono); display: block; margin-bottom: 0.5rem; }
.tl-content p { font-size: 0.875rem; color: var(--text-muted); line-height: 1.7; max-width: 680px; }

/* ---- PUBLICATIONS ---- */
.pub-filter { display: flex; gap: 0.5rem; margin-bottom: 2.5rem; flex-wrap: wrap; }
.pub-btn {
  background: transparent; border: 1px solid var(--border);
  color: var(--text-muted); padding: 0.35rem 1rem; border-radius: var(--radius);
  cursor: pointer; font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.04em;
  transition: all 0.2s;
}
.pub-btn:hover { border-color: var(--border-hover); color: var(--text); }
.pub-btn.active { background: var(--accent-soft); border-color: rgba(200,150,74,0.4); color: var(--accent); }
.pub-list { display: flex; flex-direction: column; gap: 1rem; }
.pub-item {
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 1.5rem 1.75rem;
  transition: border-color 0.3s, transform 0.2s;
}
.pub-item:hover { border-color: var(--border-hover); transform: translateX(4px); }
.pub-item.hidden { display: none; }
.pub-meta { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.6rem; }
.pub-badge {
  font-size: 0.65rem; padding: 3px 9px; border-radius: 3px; letter-spacing: 0.08em;
}
.pub-badge.journal { background: rgba(74,200,180,0.12); color: var(--teal); }
.pub-badge.forthcoming { background: var(--accent-soft); color: var(--accent); }
.pub-badge.conference { background: rgba(74,144,200,0.12); color: var(--blue); }
.pub-year { color: var(--text-dim); font-size: 0.7rem; }
.pub-item h4 { font-weight: 400; font-size: 0.95rem; color: var(--text); margin-bottom: 0.4rem; line-height: 1.5; }
.pub-authors { font-size: 0.8rem; color: var(--text-muted); margin-bottom: 0.25rem; }
.pub-journal { color: var(--text-dim); font-size: 0.72rem; }
.pub-doi { color: var(--accent); font-size: 0.7rem; text-decoration: none; display: block; margin-top: 0.4rem; }
.pub-doi:hover { text-decoration: underline; }

/* ---- BLOG ---- */
.blog-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 1.25rem;
  margin-bottom: 2rem;
}
.blog-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); overflow: hidden;
  transition: border-color 0.3s, transform 0.3s;
  cursor: default;
}
.blog-card:hover { border-color: var(--border-hover); transform: translateY(-4px); }
.blog-card--featured { grid-row: 1 / 3; }
.blog-card-inner { padding: 2rem; height: 100%; display: flex; flex-direction: column; }
.blog-meta { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.blog-cat { color: var(--accent); font-size: 0.68rem; letter-spacing: 0.08em; }
.blog-date { color: var(--text-dim); font-size: 0.68rem; }
.blog-card h3 {
  font-family: var(--serif); font-size: 1.2rem; font-weight: 400;
  color: var(--text); line-height: 1.4; margin-bottom: 0.75rem;
}
.blog-card--featured h3 { font-size: 1.6rem; }
.blog-card p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.65; flex: 1; }
.blog-read { color: var(--text-dim); font-size: 0.7rem; margin-top: 1.5rem; display: block; }
.blog-note { color: var(--text-dim); font-size: 0.75rem; text-align: center; padding: 1.5rem; }

/* ---- CONTACT ---- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; align-items: start; }
.contact-text .lead { margin-bottom: 2rem; }
.contact-links { display: flex; flex-direction: column; gap: 1rem; }
.contact-link {
  display: flex; align-items: center; gap: 1rem;
  padding: 1rem 1.25rem;
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: var(--radius-lg); text-decoration: none;
  transition: border-color 0.3s, transform 0.2s;
}
.contact-link:hover { border-color: var(--accent-glow); transform: translateX(4px); }
.contact-icon { font-size: 1.1rem; width: 36px; height: 36px; display: flex; align-items: center; justify-content: center; background: var(--accent-soft); border-radius: 8px; }
.contact-link span.mono { color: var(--text-dim); font-size: 0.68rem; display: block; margin-bottom: 2px; letter-spacing: 0.08em; }
.contact-link strong { color: var(--text); font-size: 0.82rem; font-weight: 400; word-break: break-all; }
.contact-form-wrap {
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 2rem;
}
.form-group { margin-bottom: 1.25rem; }
.form-group label { display: block; color: var(--text-dim); font-size: 0.7rem; margin-bottom: 0.4rem; letter-spacing: 0.08em; }
.form-group input,
.form-group textarea {
  width: 100%; background: var(--bg2); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 0.65rem 0.9rem;
  color: var(--text); font-family: var(--sans); font-size: 0.875rem;
  transition: border-color 0.2s;
  outline: none; resize: vertical;
}
.form-group input:focus,
.form-group textarea:focus { border-color: rgba(200,150,74,0.5); }
.form-group input::placeholder,
.form-group textarea::placeholder { color: var(--text-dim); }
.form-note { color: var(--text-dim); font-size: 0.68rem; margin-top: 0.75rem; text-align: center; line-height: 1.6; }
.form-note a { color: var(--accent); }

/* ---- FOOTER ---- */
.footer { background: var(--bg); border-top: 1px solid var(--border); padding: 3rem 0 2rem; }
.footer-inner { display: grid; grid-template-columns: 1fr auto; gap: 2rem; align-items: start; }
.footer-left { display: flex; flex-direction: column; gap: 0.4rem; }
.footer-left .nav-logo { font-size: 1.3rem; }
.footer-left p { color: var(--text-dim); font-size: 0.72rem; }
.footer-left a { color: var(--accent); text-decoration: none; }
.footer-links { display: flex; gap: 1.5rem; flex-wrap: wrap; padding-top: 0.25rem; }
.footer-links a { color: var(--text-muted); text-decoration: none; font-size: 0.82rem; transition: color 0.2s; }
.footer-links a:hover { color: var(--accent); }
.footer-bottom {
  grid-column: 1 / -1; display: flex; justify-content: space-between;
  color: var(--text-dim); font-size: 0.68rem;
  padding-top: 1.5rem; margin-top: 1.5rem; border-top: 1px solid var(--border);
  flex-wrap: wrap; gap: 0.5rem;
}

/* ---- SCROLL ANIMATIONS ---- */
[data-animate] { opacity: 0; transform: translateY(28px); transition: opacity 0.6s var(--ease), transform 0.6s var(--ease); }
[data-animate].in-view { opacity: 1; transform: translateY(0); }
[data-delay="80"] { transition-delay: 80ms; }
[data-delay="100"] { transition-delay: 100ms; }
[data-delay="120"] { transition-delay: 120ms; }
[data-delay="140"] { transition-delay: 140ms; }
[data-delay="150"] { transition-delay: 150ms; }
[data-delay="160"] { transition-delay: 160ms; }
[data-delay="180"] { transition-delay: 180ms; }
[data-delay="200"] { transition-delay: 200ms; }
[data-delay="220"] { transition-delay: 220ms; }
[data-delay="240"] { transition-delay: 240ms; }
[data-delay="260"] { transition-delay: 260ms; }
[data-delay="280"] { transition-delay: 280ms; }
[data-delay="320"] { transition-delay: 320ms; }

/* ---- MOBILE ---- */
@media (max-width: 1024px) {
  .research-pillars { grid-template-columns: 1fr 1fr; }
  .about-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .about-sidebar { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }
  .about-sidebar .sidebar-card { margin-bottom: 0; }
}

@media (max-width: 860px) {
  .hero-inner { grid-template-columns: 1fr; gap: 2.5rem; }
  .hero-photo-wrap { order: -1; align-items: center; }
  .hero-text { text-align: center; }
  .hero-desc, .hero-actions, .hero-tags { justify-content: center; }
  .hero-desc { max-width: 100%; }
  .blog-grid { grid-template-columns: 1fr; }
  .blog-card--featured { grid-row: auto; }
  .contact-grid { grid-template-columns: 1fr; gap: 2.5rem; }
}

@media (max-width: 768px) {
  .nav-toggle { display: flex; z-index: 110; }
  .nav-links {
    position: fixed; inset: 0; background: var(--bg);
    flex-direction: column; justify-content: center; gap: 0.5rem;
    opacity: 0; pointer-events: none; transition: opacity 0.3s;
    font-size: 1.2rem;
  }
  .nav-links.open { opacity: 1; pointer-events: all; }
  .nav-links a { padding: 0.75rem 2rem; font-size: 1rem; }
  .nav-links .nav-cta { margin-left: 0; }
  .about-sidebar { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-links { gap: 1rem; }
  .research-pillars { grid-template-columns: 1fr; }
  .about-stats { gap: 1.5rem; }
  .timeline { padding-left: 1rem; }
  .tl-item { padding-left: 1.5rem; }
}

@media (max-width: 480px) {
  .container { padding: 0 1.25rem; }
  .section { padding: 5rem 0; }
  .hero-name { font-size: 2.6rem; }
  .photo-frame { width: 220px; height: 260px; }
}