/* Base theme tokens */
:root {
  --bg: #0b0c0f;
  --card: #12141a;
  --text: #eef2f7;
  --muted: #b7c1d1;
  --accent: #7c92ff;
  --accent-strong: #5c73ff;
  --border: #242834;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

[data-theme="light"] {
  --bg: #ffffff;
  --card: #f6f7fb;
  --text: #0b0c0f;
  --muted: #3f4654;
  --accent: #3b5bfd;
  --accent-strong: #2a47e8;
  --border: #e8ebf3;
  --shadow: 0 12px 24px rgba(21, 24, 32, 0.08);
}

/* Reset */
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  color: var(--text);
  background: radial-gradient(1200px 800px at 80% -10%, rgba(92,115,255,0.18), transparent 60%), var(--bg);
  line-height: 1.55;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; padding: 0; margin: 0; }

/* Layout */
.container {
  width: min(1100px, 92%);
  margin: 0 auto;
}

.section { padding: 72px 0; }
.section.alt { background: linear-gradient(180deg, transparent, rgba(255,255,255,0.02) 10%, transparent 90%); }
.section h2 { font-size: 28px; margin: 0 0 8px; letter-spacing: -0.02em; text-align: center; }
.section .section-lead { color: var(--muted); margin: 0 0 28px; text-align: center; }
/* simple list styling for resume sections */
.bulleted { margin: 0; padding-left: 18px; }
.bulleted li { list-style: disc; margin: 6px 0; color: var(--muted); }
.edu-list, .exp-list { display: grid; gap: 14px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: saturate(180%) blur(12px);
  background: color-mix(in oklab, var(--bg) 86%, transparent);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 4%;
  transition: transform 200ms ease;
  will-change: transform;
}

.site-header.header-hidden { transform: translateY(-100%); }

.brand { font-weight: 700; letter-spacing: -0.02em; }

.site-nav { display: flex; align-items: center; gap: 12px; }
.site-nav ul { display: flex; align-items: center; gap: 12px; }
.site-nav a { padding: 10px 12px; border-radius: 10px; color: var(--muted); }
.site-nav a:hover { color: var(--text); background: var(--card); box-shadow: var(--shadow); }

.nav-toggle { display: none; background: transparent; border: 0; padding: 8px; border-radius: 10px; }
.nav-toggle .bar { display: block; width: 22px; height: 2px; background: var(--text); margin: 5px 0; border-radius: 2px; }

.theme-toggle { border: 1px solid var(--border); background: var(--card); color: var(--text); padding: 8px 10px; border-radius: 10px; cursor: pointer; }
.theme-toggle:hover { box-shadow: var(--shadow); }

/* Hero */
.hero .hero-grid { display: grid; grid-template-columns: 1fr; gap: 24px; align-items: center; justify-items: center; }
.hero.section { min-height: 80vh; display: flex; align-items: center; }
.hero h1 { font-size: clamp(28px, 4vw, 44px); margin: 0 0 12px; letter-spacing: -0.03em; text-align: center; }
.lead { color: var(--muted); margin: 0 0 20px; }
.lead.stacked { display: grid; gap: 4px; justify-items: center; text-align: center; }
.hero-actions { display: flex; gap: 12px; }
.hero-text { text-align: center; }
.hero-actions { justify-content: center; }
.accent { color: var(--accent); }

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 16px; border: 1px solid var(--border); border-radius: 12px; color: var(--text); background: var(--card); box-shadow: var(--shadow); }
.btn:hover { transform: translateY(-1px); }
.btn.primary { background: var(--accent); border-color: var(--accent-strong); color: white; }
.btn.primary:hover { filter: brightness(0.98); }

/* Projects */
.projects-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.project-card { background: var(--card); border: 1px solid var(--border); border-radius: 16px; box-shadow: var(--shadow); display: flex; flex-direction: column; }
.project-card .content { padding: 14px; display: grid; gap: 8px; }
.project-card .title { font-weight: 600; letter-spacing: -0.01em; }
.project-card .desc { color: var(--muted); }
.project-card .tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 4px; }
.project-card .tag { font-size: 12px; padding: 6px 8px; border: 1px solid var(--border); border-radius: 999px; color: var(--muted); background: color-mix(in oklab, var(--card) 88%, transparent); }

/* Education overrides: single column, centered */
.edu-grid { grid-template-columns: 1fr; }
.edu-grid .content { text-align: center; }
.edu-grid .tags { justify-content: center; }

/* Work Experience: use same boxy card style, centered single column */
.exp-grid { grid-template-columns: 1fr; justify-items: center; }
.exp-grid .project-card { width: 100%; max-width: 820px; }
.exp-grid .content { text-align: center; display: grid; gap: 8px; }
.exp-grid .exp-points { list-style: none; margin: 8px 0 0; padding: 0; color: var(--muted); display: grid; gap: 6px; justify-items: center; }

/* Skills split into three cards */
.skills-grid .content { text-align: center; }
.skills-list { list-style: disc; margin: 8px auto 0; padding-left: 18px; color: var(--muted); text-align: left; width: fit-content; }

/* Certificates in boxy cards, centered */
.certs-grid { grid-template-columns: 1fr; justify-items: center; }
.certs-grid .project-card { width: 100%; max-width: 820px; }
.certs-grid .content { text-align: center; }

/* Activities, Awards, Languages in card style */
.activities-grid, .awards-grid, .languages-grid { grid-template-columns: 1fr; justify-items: center; }
.activities-grid .project-card, .awards-grid .project-card, .languages-grid .project-card { width: 100%; max-width: 820px; }
.activities-grid .content, .awards-grid .content, .languages-grid .content { text-align: center; }

/* Contact */
.contact-actions {
  display: grid;
  gap: 14px;
  justify-items: center;
}

/* Footer */
.site-footer { border-top: 1px solid var(--border); padding: 28px 0; color: var(--muted); text-align: center; }

/* Responsive */
@media (max-width: 920px) {
  .hero .hero-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .projects-grid { grid-template-columns: 1fr; }
  .nav-toggle { display: inline-block; }
  .site-nav ul { display: none; position: absolute; right: 4%; top: 56px; background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 8px; box-shadow: var(--shadow); }
  .site-nav ul.open { display: grid; gap: 4px; }
  .site-nav a { display: block; }
}

/* Push research below initial viewport */
.section.delayed { margin-top: 12vh; }