/* ====== Theme tokens ====== */
:root {
  --bg: #0b0f14;
  --bg-alt: #0f141a;
  --text: #e6f0ff;
  --muted: #b3c2d1;
  --primary: #4cc9f0;
  --primary-strong: #3bb8e4;
  --card: #16202a;
  --border: #22303c;
  --accent: linear-gradient(135deg, #4cc9f0 0%, #4361ee 50%, #7209b7 100%);
}

:root.light {
  --bg: #f7fbff;
  --bg-alt: #f1f6fb;
  --text: #0f141a;
  --muted: #384b5a;
  --card: #ffffff;
  --border: #dae6f3;
}

/* ====== Base ====== */
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container { max-width: 1000px; margin: 0 auto; padding: 0 20px; }
.section { padding: 64px 0; }
.section.alt { background: var(--bg-alt); }

/* ====== Header / Nav ====== */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: rgba(11,15,20,0.75);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border);
}
:root.light .site-header { background: rgba(247,251,255,0.75); }

.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}

.brand {
  font-weight: 800; letter-spacing: 0.5px;
  background: var(--accent); -webkit-background-clip: text; background-clip: text; color: transparent;
  font-size: 1.1rem;
}

.nav a {
  color: var(--muted); margin: 0 10px; text-decoration: none; font-weight: 500;
}
.nav a:hover { color: var(--text); }

.theme-toggle {
  background: transparent; color: var(--muted);
  border: 1px solid var(--border); border-radius: 10px;
  padding: 6px 10px; cursor: pointer; transition: background .15s ease, color .15s ease;
}
.theme-toggle:hover { background: var(--card); color: var(--text); }

/* ====== Hero ====== */
.hero { position: relative; padding: 96px 0 64px; overflow: hidden; }
.hero .gradient {
  position: absolute; inset: -20%;
  background:
    radial-gradient(600px 300px at 70% 10%, rgba(114,9,183,.35), transparent 60%),
    radial-gradient(400px 250px at 20% 40%, rgba(67,97,238,.25), transparent 60%),
    radial-gradient(500px 300px at 50% 90%, rgba(76,201,240,.20), transparent 60%);
  filter: blur(30px); z-index: -1;
}
.hero h1 { font-size: clamp(2.2rem, 4vw, 3.2rem); margin: 0 0 10px; }
.tagline { color: var(--muted); margin: 6px 0 16px; }
.summary { max-width: 72ch; color: #d5e4f7; line-height: 1.65; }

/* ====== Buttons & Links ====== */
.btn {
  display: inline-block; padding: 10px 16px; border-radius: 10px;
  border: 1px solid #274357; color: #bcd3ea; text-decoration: none; margin-right: 10px;
  transition: transform .08s ease, background .15s ease, color .15s ease, border-color .15s ease;
}
.btn:hover { transform: translateY(-1px); color: #e6f0ff; border-color: #3d6a88; }
.btn.primary { background: var(--accent); color: #fff; border: none; }
.btn.primary:hover { filter: brightness(1.05); }

/* ====== Cards, Grids, Lists ====== */
.grid.two { display: grid; grid-template-columns: 1.1fr .9fr; gap: 28px; }
@media (max-width: 820px) { .grid.two { grid-template-columns: 1fr; } }

.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
@media (max-width: 900px) { .cards { grid-template-columns: 1fr; } }

.card {
  background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 20px;
  box-shadow: 0 0 0 1px rgba(0,0,0,0), 0 4px 18px rgba(0,0,0,0.18);
}
.card h3 { margin-top: 0; }

.timeline { padding-left: 18px; }
.timeline li { margin: 8px 0; }

.facts { padding-left: 18px; }

.skills {
  display: flex; flex-wrap: wrap; gap: 10px; list-style: none; padding: 0; margin: 0;
}
.skills li {
  background: #15212c; border: 1px solid var(--border); padding: 8px 12px; border-radius: 999px; color: #cfe2f3;
}
:root.light .skills li { background: #f1f6fb; color: #173047; }

.links { list-style: none; padding: 0; display: flex; gap: 14px; flex-wrap: wrap; }
.links a {
  color: #a9c8e8; text-decoration: none; border-bottom: 1px dashed #375a79; padding-bottom: 1px;
}
.links a:hover { color: #e6f0ff; border-bottom-color: transparent; }
:root.light .links a { color: #1e4b7a; border-bottom-color: #7aa3c7; }
:root.light .links a:hover { color: #0d2f53; }

/* ====== Footer ====== */
.site-footer {
  border-top: 1px solid var(--border); padding: 24px 0; color: var(--muted); font-size: .95rem;
}

/* ====== Utilities ====== */
.center { text-align: center; }
.mt-2 { margin-top: .5rem; } .mt-4 { margin-top: 1rem; } .mt-6 { margin-top: 1.5rem; }