/* ---------- Font ---------- */
@font-face {
  font-family: 'Inter';
  src: url('assets/fonts/inter-latin.woff2') format('woff2');
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

/* ---------- Tokens ---------- */
:root {
  --bg: #ffffff;
  --bg-soft: #f7f8fb;
  --text: #101219;
  --text-muted: #5a5f73;
  --accent: #3f5ae8;
  --border: #e3e6ef;
  --btn-bg: #f3f4f9;
  --btn-bg-hover: #e8eaf4;
  --shadow: 0 1px 2px rgba(16,18,25,.05), 0 8px 24px rgba(16,18,25,.05);
  --maxw: 1080px;
}

:root[data-theme="dark"] {
  --bg: #0c0e13;
  --bg-soft: #12141c;
  --text: #f1f2f7;
  --text-muted: #939ab1;
  --accent: #7f95ff;
  --border: #222634;
  --btn-bg: #171a24;
  --btn-bg-hover: #1f2432;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 28px rgba(0,0,0,.35);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 90px;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background .25s ease, color .25s ease;
}

a { color: inherit; }

/* ---------- Top bar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: .9rem 2rem;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s ease;
}

.topbar.scrolled { border-bottom-color: var(--border); }

.brand {
  font-weight: 800;
  letter-spacing: .06em;
  text-decoration: none;
  font-size: 1.05rem;
}

.nav {
  display: flex;
  gap: 1.6rem;
  margin-left: auto;
  font-size: .9rem;
}

.nav a {
  color: var(--text-muted);
  text-decoration: none;
  position: relative;
  transition: color .2s ease;
}

.nav a::after {
  content: '';
  position: absolute;
  left: 0; bottom: -5px;
  width: 100%; height: 1.5px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .25s ease;
}

.nav a:hover { color: var(--text); }
.nav a:hover::after,
.nav a.active::after { transform: scaleX(1); }
.nav a.active { color: var(--text); }

.theme-toggle {
  background: var(--btn-bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  width: 38px; height: 38px;
  display: grid; place-items: center;
  cursor: pointer;
  color: var(--text);
  flex-shrink: 0;
  transition: background .2s ease;
}
.theme-toggle:hover { background: var(--btn-bg-hover); }
.theme-toggle svg { width: 17px; height: 17px; }

.icon-moon { display: none; }
:root[data-theme="dark"] .icon-sun { display: none; }
:root[data-theme="dark"] .icon-moon { display: block; }

/* ---------- Layout ---------- */
main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 2rem;
}

.section { padding: 5rem 0 1rem; }

.section h2 {
  font-size: 1.6rem;
  letter-spacing: -.02em;
  margin: 0 0 2rem;
  display: flex;
  align-items: baseline;
  gap: .7rem;
}

.num {
  color: var(--accent);
  font-size: .95rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* ---------- Hero ---------- */
.hero {
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 3.5rem;
  align-items: center;
  min-height: calc(100vh - 140px);
  padding: 2rem 0 3rem;
}

.eyebrow {
  color: var(--accent);
  font-weight: 600;
  font-size: .95rem;
  margin: 0 0 .4rem;
}

h1 {
  font-size: clamp(2.4rem, 5.5vw, 3.6rem);
  line-height: 1.08;
  letter-spacing: -.035em;
  margin: 0 0 .8rem;
  font-weight: 700;
}

.tagline {
  color: var(--text-muted);
  font-size: 1rem;
  font-weight: 500;
  margin: 0 0 1.4rem;
}

.bio {
  color: var(--text-muted);
  max-width: 50ch;
  margin: 0 0 2rem;
}

.bio a, .tl-item a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, var(--accent) 40%, transparent);
  transition: border-color .2s ease;
}
.bio a:hover, .tl-item a:hover { border-bottom-color: var(--accent); }

.links { display: flex; flex-wrap: wrap; gap: .7rem; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .6rem 1.05rem;
  border-radius: 9px;
  background: var(--btn-bg);
  border: 1px solid var(--border);
  text-decoration: none;
  font-size: .9rem;
  font-weight: 500;
  transition: background .2s ease, transform .15s ease, border-color .2s ease;
}
.btn:hover {
  background: var(--btn-bg-hover);
  border-color: color-mix(in srgb, var(--accent) 55%, var(--border));
  transform: translateY(-2px);
}
.btn-ghost { background: transparent; }

.hero-image {
  border-radius: 18px;
  overflow: hidden;
  aspect-ratio: 633 / 742;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}
.hero-image img {
  width: 100%; height: 100%;
  object-fit: cover;
  display: block;
}

/* ---------- Achievements strip ---------- */
.strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  margin: 1rem 0 2rem;
}
.strip-item {
  background: var(--bg-soft);
  padding: 1.1rem 1.2rem;
  display: flex;
  flex-direction: column;
  gap: .15rem;
}
.strip-item b {
  font-size: 1.05rem;
  letter-spacing: -.01em;
}
.strip-item span {
  font-size: .78rem;
  color: var(--text-muted);
  line-height: 1.45;
}

/* ---------- About ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  color: var(--text-muted);
}
.about-grid p { margin: 0; }

/* ---------- Timeline ---------- */
.timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 1.6rem;
  border-left: 1px solid var(--border);
}

.tl-item {
  position: relative;
  padding-bottom: 2.4rem;
}
.tl-item:last-child { padding-bottom: .5rem; }

.tl-item::before {
  content: '';
  position: absolute;
  left: calc(-1.6rem - 5px);
  top: .55rem;
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--accent);
}

.tl-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: .5rem;
}

.tl-head h3 {
  font-size: 1.05rem;
  margin: 0;
  font-weight: 600;
  letter-spacing: -.01em;
}

.tl-date {
  font-size: .8rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.tl-org {
  color: var(--accent);
  font-size: .88rem;
  font-weight: 500;
  margin: .2rem 0 .6rem;
}

.tl-item ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--text-muted);
  font-size: .92rem;
}
.tl-item li { margin-bottom: .35rem; }

/* ---------- Project cards ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 1.1rem;
}

.card {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.card:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--accent) 45%, var(--border));
  box-shadow: var(--shadow);
}

.card h3 {
  font-size: 1.02rem;
  margin: 0 0 .3rem;
  font-weight: 600;
  letter-spacing: -.01em;
}

.medal {
  display: inline-block;
  font-size: .68rem;
  font-weight: 600;
  padding: .1rem .45rem;
  border-radius: 5px;
  background: color-mix(in srgb, var(--accent) 16%, transparent);
  color: var(--accent);
  vertical-align: middle;
  margin-left: .3rem;
}

.card-meta {
  font-size: .78rem;
  color: var(--accent);
  margin: 0 0 .7rem;
  font-weight: 500;
}

.card p {
  font-size: .9rem;
  color: var(--text-muted);
  margin: 0 0 1rem;
}

.card code {
  font-family: ui-monospace, 'SF Mono', Menlo, monospace;
  font-size: .85em;
  background: var(--btn-bg);
  padding: .05rem .3rem;
  border-radius: 4px;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
  margin-top: auto;
}
.tags span {
  font-size: .74rem;
  padding: .22rem .55rem;
  border-radius: 6px;
  background: var(--btn-bg);
  border: 1px solid var(--border);
  color: var(--text-muted);
}

.card-link {
  margin-top: .9rem;
  font-size: .84rem;
  font-weight: 500;
  color: var(--accent);
  text-decoration: none;
}
.card-link:hover { text-decoration: underline; }

/* ---------- Skills ---------- */
.skills {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1.6rem;
}
.skill-group h4 {
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-muted);
  margin: 0 0 .7rem;
  font-weight: 600;
}

/* ---------- Contact ---------- */
.contact { padding-bottom: 4rem; }
.contact p { color: var(--text-muted); max-width: 48ch; }
.mail-link {
  display: inline-block;
  font-size: clamp(1.1rem, 3vw, 1.6rem);
  font-weight: 600;
  letter-spacing: -.02em;
  color: var(--accent);
  text-decoration: none;
  margin: .4rem 0 1.6rem;
  border-bottom: 2px solid transparent;
  transition: border-color .2s ease;
}
.mail-link:hover { border-bottom-color: var(--accent); }

/* ---------- Footer ---------- */
footer {
  border-top: 1px solid var(--border);
  margin-top: 3rem;
  padding: 1.8rem;
  text-align: center;
  color: var(--text-muted);
  font-size: .82rem;
}
footer p { margin: 0; }

/* ---------- Reveal animation ---------- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s cubic-bezier(.2,.7,.3,1), transform .6s cubic-bezier(.2,.7,.3,1);
}
.reveal.visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  * { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .about-grid { grid-template-columns: 1fr; gap: 1rem; }
}

@media (max-width: 760px) {
  .topbar { padding: .8rem 1.2rem; gap: 1rem; }
  .nav { display: none; }
  main { padding: 0 1.2rem; }
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    min-height: auto;
    gap: 2rem;
  }
  .hero-image { order: -1; max-width: 260px; margin: 0 auto; }
  .bio { margin-left: auto; margin-right: auto; }
  .links { justify-content: center; }
  .section { padding: 3.5rem 0 1rem; }
  .tl-head { justify-content: flex-start; }
}

@media (max-width: 460px) {
  .strip { grid-template-columns: 1fr; }
}

/* ---------- Hero photo rotation ---------- */
.hero-image { position: relative; }

.hero-slide {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity .9s ease;
}
.hero-slide.is-active { opacity: 1; }

.hero-dots {
  position: absolute;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 6px;
  padding: 5px 8px;
  border-radius: 999px;
  background: rgba(0, 0, 0, .32);
  backdrop-filter: blur(6px);
}
.hero-dots[hidden] { display: none; }

.hero-dot {
  width: 7px;
  height: 7px;
  padding: 0;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, .45);
  cursor: pointer;
  transition: background .25s ease, transform .25s ease;
}
.hero-dot:hover { background: rgba(255, 255, 255, .75); }
.hero-dot.is-active { background: #fff; transform: scale(1.15); }

@media (prefers-reduced-motion: reduce) {
  .hero-slide { transition: none; }
}