/* =========================================================
   Siva — Portfolio
   Theme: Light + Indigo/Teal, Inter + Space Grotesk
   ========================================================= */

:root {
  /* Palette */
  --color-bg: #ffffff;
  --color-surface: #f8fafc;
  --color-surface-2: #f1f5f9;
  --color-border: #e2e8f0;
  --color-border-strong: #cbd5e1;
  --color-text: #0f172a;
  --color-text-muted: #475569;
  --color-text-subtle: #64748b;
  --color-primary: #4f46e5;       /* Indigo 600 */
  --color-primary-700: #4338ca;
  --color-primary-50: #eef2ff;
  --color-accent: #0d9488;        /* Teal 600 */
  --color-accent-50: #f0fdfa;
  --color-success: #16a34a;

  /* Typography */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-display: "Space Grotesk", "Inter", system-ui, sans-serif;

  /* Layout */
  --radius-sm: 6px;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow: 0 8px 24px -8px rgba(15, 23, 42, 0.12), 0 2px 6px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 20px 40px -12px rgba(15, 23, 42, 0.18);
  --container: 1200px;
  --gutter: clamp(16px, 4vw, 32px);
  --header-h: 72px;
}

/* ----- Reset ----- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; height: auto; }
a { color: var(--color-primary); text-decoration: none; transition: color .15s ease; }
a:hover { color: var(--color-primary-700); }
button { font: inherit; cursor: pointer; }

/* ----- Layout helpers ----- */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}
.section { padding: clamp(56px, 8vw, 112px) 0; }
.section--tight { padding: clamp(40px, 6vw, 72px) 0; }
.section--alt { background: var(--color-surface); }

/* ----- Typography ----- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--color-text);
  letter-spacing: -0.015em;
  line-height: 1.2;
  margin: 0 0 0.5em;
  font-weight: 600;
}
h1 { font-size: clamp(2.25rem, 4.6vw, 3.75rem); letter-spacing: -0.025em; }
h2 { font-size: clamp(1.75rem, 3.2vw, 2.5rem); }
h3 { font-size: clamp(1.15rem, 2vw, 1.35rem); }
p  { margin: 0 0 1em; color: var(--color-text-muted); }
.eyebrow {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-primary);
  background: var(--color-primary-50);
  padding: 6px 12px;
  border-radius: 999px;
  margin-bottom: 18px;
}
.section-head {
  max-width: 720px;
  margin: 0 auto 48px;
  text-align: center;
}
.section-head p { font-size: 1.05rem; }

/* ----- Header / Nav ----- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: 24px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--color-text);
}
.brand:hover { color: var(--color-primary); }
.brand-mark {
  width: 32px; height: 32px;
  display: grid; place-items: center;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  box-shadow: var(--shadow-sm);
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  margin: 0; padding: 0;
}
.nav-links a {
  display: inline-block;
  padding: 6px 10px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--color-text-muted);
  border-radius: 8px;
  transition: background .15s ease, color .15s ease;
}
.nav-links a:hover { color: var(--color-text); background: var(--color-surface-2); }
.nav-links a.is-active { color: var(--color-primary); background: var(--color-primary-50); }
.nav-cta { margin-left: 8px; }
.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 8px 10px;
  color: var(--color-text);
}

/* ----- Buttons ----- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: transform .12s ease, background .15s ease, border-color .15s ease, color .15s ease, box-shadow .15s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn--primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 6px 16px -6px rgba(79,70,229,.55);
}
.btn--primary:hover { background: var(--color-primary-700); color: #fff; }
.btn--ghost {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border-strong);
}
.btn--ghost:hover { background: var(--color-surface); }
.btn--accent {
  background: var(--color-accent);
  color: #fff;
}
.btn--accent:hover { background: #0f766e; color: #fff; }

/* ----- Hero ----- */
.hero {
  position: relative;
  padding: clamp(72px, 10vw, 128px) 0 clamp(56px, 8vw, 96px);
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute; inset: 0;
  background:
    radial-gradient(800px 400px at 12% -10%, var(--color-primary-50) 0%, transparent 60%),
    radial-gradient(700px 360px at 95% 0%, var(--color-accent-50) 0%, transparent 60%);
  z-index: -1;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: 56px;
  align-items: center;
}
.hero h1 { margin-bottom: 18px; }
.hero-lead {
  font-size: clamp(1.05rem, 1.5vw, 1.18rem);
  color: var(--color-text-muted);
  max-width: 56ch;
  margin-bottom: 28px;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 28px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  display: inline-block;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.82rem;
  font-weight: 500;
}
.hero-card {
  position: relative;
  padding: 28px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}
.hero-card::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-lg);
  padding: 1px;
  background: linear-gradient(135deg, rgba(79,70,229,.35), rgba(13,148,136,.25));
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  pointer-events: none;
}
.hero-card h3 { margin-bottom: 4px; }
.hero-card .role { color: var(--color-accent); font-weight: 600; font-size: 0.95rem; margin-bottom: 18px; }
.hero-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; }
.hero-list li {
  display: flex; gap: 10px; align-items: flex-start;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}
.hero-list li::before {
  content: "";
  display: inline-block;
  width: 6px; height: 6px;
  margin-top: 9px;
  border-radius: 50%;
  background: var(--color-primary);
  flex: none;
}
.social-row { display: flex; gap: 10px; margin-top: 22px; flex-wrap: wrap; }
.social-pill {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 12px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: 8px;
  font-size: 0.86rem;
  color: var(--color-text);
  font-weight: 500;
}
.social-pill:hover { border-color: var(--color-primary); color: var(--color-primary); background: var(--color-primary-50); }

/* ----- Page header (subpage hero) ----- */
.page-hero {
  padding: clamp(64px, 8vw, 112px) 0 clamp(40px, 5vw, 64px);
  position: relative;
  background:
    radial-gradient(900px 380px at 50% -10%, var(--color-primary-50) 0%, transparent 60%),
    var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}
.page-hero-inner { max-width: 820px; margin: 0 auto; text-align: center; }
.page-hero p { font-size: 1.08rem; }

/* ----- Card grid (talks/media) ----- */
.cards {
  display: grid;
  gap: 28px;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
}
.card {
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.card:hover {
  transform: translateY(-3px);
  border-color: var(--color-border-strong);
  box-shadow: var(--shadow);
}
.card-media {
  position: relative;
  aspect-ratio: 16 / 10;
  background: linear-gradient(135deg, var(--color-primary-50), var(--color-accent-50));
  overflow: hidden;
}
.card-media img {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform .4s ease;
}
.card:hover .card-media img { transform: scale(1.04); }
.card-media-fallback {
  position: absolute; inset: 0;
  display: grid; place-items: center;
  font-family: var(--font-display);
  font-size: 2.2rem; font-weight: 700;
  color: rgba(79,70,229,.35);
  letter-spacing: -0.02em;
}
.card-body { padding: 22px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
.card-meta {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.78rem; font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.card-meta::before {
  content: ""; width: 6px; height: 6px; border-radius: 50%;
  background: var(--color-accent);
}
.card-title {
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 600;
  color: var(--color-text);
  margin: 0;
  line-height: 1.35;
}
.card-desc { color: var(--color-text-muted); font-size: 0.95rem; margin: 0; }
.card-link {
  margin-top: auto;
  display: inline-flex; align-items: center; gap: 6px;
  font-weight: 600; font-size: 0.9rem;
  color: var(--color-primary);
  padding-top: 8px;
}
.card-link::after {
  content: "→";
  transition: transform .15s ease;
}
.card-link:hover::after { transform: translateX(3px); }

/* ----- Interview row ----- */
.interview-list {
  display: grid;
  gap: 18px;
}
.interview {
  display: grid;
  grid-template-columns: 100px 1fr auto;
  align-items: center;
  gap: 24px;
  padding: 22px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}
.interview-date {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--color-primary);
  font-size: 0.95rem;
}
.interview h4 { margin: 0 0 4px; font-size: 1.05rem; font-family: var(--font-display); }
.interview p { margin: 0; color: var(--color-text-muted); font-size: 0.95rem; }

/* ----- Timeline (conferences) ----- */
.timeline {
  position: relative;
  padding-left: 32px;
  margin: 0;
  list-style: none;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 10px; top: 6px; bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--color-primary), var(--color-accent));
  border-radius: 2px;
}
.timeline-item { position: relative; padding: 18px 0 18px 24px; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -28px; top: 26px;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: #fff;
  border: 3px solid var(--color-primary);
  box-shadow: 0 0 0 4px var(--color-primary-50);
}
.timeline-year {
  display: inline-block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--color-primary);
  background: var(--color-primary-50);
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 8px;
}
.timeline-title { font-family: var(--font-display); font-size: 1.05rem; margin: 0 0 4px; }
.timeline-meta { color: var(--color-text-subtle); font-size: 0.9rem; margin: 0 0 6px; }
.timeline a { font-weight: 600; font-size: 0.9rem; }

/* ----- Stats ----- */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin-top: 40px;
}
.stat {
  padding: 24px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  text-align: center;
}
.stat-value {
  font-family: var(--font-display);
  font-size: 2rem; font-weight: 700;
  color: var(--color-primary);
  display: block;
  letter-spacing: -0.02em;
}
.stat-label {
  color: var(--color-text-muted);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ----- CTA band ----- */
.cta-band {
  padding: clamp(48px, 8vw, 80px) 0;
  background: linear-gradient(135deg, var(--color-primary), #6366f1 60%, var(--color-accent));
  color: #fff;
  text-align: center;
}
.cta-band h2 { color: #fff; }
.cta-band p { color: rgba(255,255,255,.85); max-width: 620px; margin: 0 auto 24px; }
.cta-band .btn--primary { background: #fff; color: var(--color-primary); box-shadow: none; }
.cta-band .btn--primary:hover { background: #f8fafc; color: var(--color-primary-700); }
.cta-band .btn--ghost { color: #fff; border-color: rgba(255,255,255,.4); }
.cta-band .btn--ghost:hover { background: rgba(255,255,255,.1); }

/* ----- Footer ----- */
.site-footer {
  padding: 56px 0 32px;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 36px;
}
.footer-grid h4 {
  font-family: var(--font-display);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text);
  margin: 0 0 14px;
}
.footer-grid ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.footer-grid a { color: var(--color-text-muted); font-size: 0.92rem; }
.footer-grid a:hover { color: var(--color-primary); }
.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap;
  gap: 12px;
  color: var(--color-text-subtle);
  font-size: 0.88rem;
}

/* ----- States ----- */
.loading, .empty {
  text-align: center;
  padding: 56px 24px;
  color: var(--color-text-subtle);
  font-size: 0.95rem;
}
.loading::after {
  content: "";
  display: inline-block;
  margin-left: 10px;
  width: 14px; height: 14px;
  border: 2px solid var(--color-border-strong);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  vertical-align: middle;
  animation: spin .9s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ----- Responsive ----- */
@media (max-width: 960px) {
  .hero-grid { grid-template-columns: 1fr; gap: 36px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 1100px) {
  .nav-links { display: none; position: absolute; top: var(--header-h); left: 0; right: 0; flex-direction: column; align-items: stretch; gap: 0; background: #fff; border-bottom: 1px solid var(--color-border); padding: 12px; z-index: 50; }
  .nav-links.is-open { display: flex; }
  .nav-links a { padding: 12px 14px; border-radius: 8px; font-size: 0.93rem; }
  .nav-toggle { display: inline-flex; }
  .nav-cta { display: none; }
  .interview { grid-template-columns: 1fr; gap: 6px; }
  .interview-date { order: -1; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

/* ----- Print ----- */
@media print {
  .site-header, .site-footer, .cta-band, .nav-cta { display: none; }
  body { color: #000; }
  a { color: #000; text-decoration: underline; }
}