/* ====== Design Tokens ====== */
:root {
  --bg: #ffffff;
  --fg: #0f172a; /* slate-900 */
  --muted: #475569; /* slate-600 */
  --card: #f8fafc; /* slate-50 */
  --border: #e2e8f0; /* slate-200 */
  --accent: #2563eb; /* blue-600 */
  --accent-weak: #dbeafe; /* blue-100 */
  --shadow: 0 1px 2px rgba(2, 6, 23, 0.06), 0 8px 24px rgba(2, 6, 23, 0.08);
  --radius: 16px;
}
/* Explicit dark-mode overrides when <html> has class="dark" */
:root.dark {
  --bg: #0b0f19;
  --fg: #e5e7eb;
  --muted: #94a3b8;
  --card: #0f172a;
  --border: #1f2937;
  --accent: #60a5fa;
  --accent-weak: #0b1220;
  --shadow: 0 1px 2px rgba(15,23,42,.5), 0 8px 24px rgba(2,6,23,.4);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0f19; /* near-black */
    --fg: #e5e7eb; /* slate-200 */
    --muted: #94a3b8; /* slate-400 */
    --card: #0f172a; /* slate-900 */
    --border: #1f2937; /* gray-800 */
    --accent: #60a5fa; /* blue-400 */
    --accent-weak: #0b1220; /* dim blue */
    --shadow: 0 1px 2px rgba(15, 23, 42, 0.5), 0 8px 24px rgba(2, 6, 23, 0.4);
  }
}

/* ====== Base ====== */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font: 16px/1.6 system-ui, -apple-system, Segoe UI, Roboto, "Helvetica Neue", Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji";
  color: var(--fg);
  background: linear-gradient(180deg, var(--bg), color-mix(in oklab, var(--bg) 90%, var(--card) 10%));
}
a { color: var(--accent); text-decoration: none; }
img { max-width: 100%; display: block; }
h1, h2, h3 { line-height: 1.2; margin: 0 0 .5rem; }
h1 { font-size: clamp(1.75rem, 2.2vw + 1rem, 2.5rem); }
h2 { font-size: clamp(1.35rem, 1.4vw + 1rem, 1.75rem); }
h3 { font-size: 1.1rem; }
p { margin: 0 0 1rem; color: var(--muted); }

.container { width: min(1100px, 100%); margin-inline: auto; padding: 0 1rem; }
.grid { display: grid; gap: 1rem; }
.grid.two { grid-template-columns: repeat(2, 1fr); }
.grid.cards { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

/* ====== Header / Nav ====== */
header {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: saturate(140%) blur(8px);
  background: color-mix(in oklab, var(--bg) 70%, transparent 30%);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: .6rem; font-weight: 700; letter-spacing: .2px; }
.brand-badge { width: 36px; height: 36px; border: 1px solid var(--border); border-radius: 12px; display: grid; place-items: center; background: var(--card); box-shadow: var(--shadow); }

.nav-links { display: none; gap: 1rem; }
.nav-links a { color: var(--muted); font-weight: 600; padding: .4rem .6rem; border-radius: 10px; }
.nav-links a:hover { background: var(--accent-weak); color: var(--fg); }

.btn { display: inline-flex; align-items: center; gap: .5rem; padding: .55rem .9rem; border-radius: 12px; border: 1px solid var(--border); background: var(--card); box-shadow: var(--shadow); color: var(--fg); font-weight: 600; }
.btn:hover { transform: translateY(-1px); }
.icon { width: 18px; height: 18px; }

/* Mobile menu */
#menu-toggle { display: none; }
.menu-btn { display: grid; place-items: center; width: 40px; height: 40px; border: 1px solid var(--border); border-radius: 12px; background: var(--card); }
.mobile-panel { display: none; padding: .5rem 0 1rem; }
#menu-toggle:checked ~ .mobile-panel { display: block; }

@media (min-width: 880px) {
  .nav-links { display: flex; }
  .menu-btn { display: none; }
  .mobile-panel { display: none !important; }
}

/* ====== Sections ====== */
section { padding: 72px 0; }
.section-head { display: flex; align-items: end; justify-content: space-between; margin-bottom: 1.25rem; }
.kicker { display: inline-block; font-size: .8rem; font-weight: 700; letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }

.card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); }
.card-pad { padding: 1rem; }

/* Hero */
.hero { display: grid; gap: 1.25rem; padding: 64px 0 40px; }
.hero h1 span { background: linear-gradient(90deg, var(--accent), color-mix(in oklab, var(--accent) 60%, #22d3ee 40%)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p { max-width: 70ch; }
.hero-cta { display: flex; gap: .6rem; flex-wrap: wrap; }

.hero-inner { display: grid; grid-template-columns: 1.2fr .8fr; gap: 1rem; align-items: center; }
.hero-photo { width: 100%; aspect-ratio: 1; object-fit: cover; border-radius: 16px; border: 1px solid var(--border); background: var(--card); }
@media (max-width: 880px) { .hero-inner { grid-template-columns: 1fr; } }

/* Projects */
.projects { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.project h3 { margin-top: .25rem; }
.stack { display: flex; gap: .4rem; flex-wrap: wrap; margin-top: .6rem; }
.tag { font-size: .75rem; padding: .25rem .5rem; border-radius: 999px; border: 1px solid var(--border); background: color-mix(in oklab, var(--card) 70%, transparent 30%); }

/* Skills */
.skills { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.skill-list { display: flex; flex-wrap: wrap; gap: .5rem; }

/* ====== Calculator UI ====== */
.calc-form select,
.calc-form input[type="number"] {
  width: 100%;
  padding: .65rem .8rem;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--fg);
  border-radius: 12px;
}
.calc-form label > span {
  display:block;
  font-size:.85rem;
  color: var(--muted);
  margin-bottom:.25rem;
}
.calc-grid {
  display:grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: .75rem;
}
.calc-output {
  margin-top: .9rem;
  padding: .9rem;
  border: 1px dashed var(--border);
  border-radius: 12px;
  background: color-mix(in oklab, var(--card) 85%, transparent 15%);
}
.result-grid {
  display:grid;
  grid-template-columns: repeat(2, minmax(120px,1fr));
  gap:.75rem;
  margin-bottom:.25rem;
}
.result-grid .num {
  font-size: 1.25rem;
  font-weight: 700;
}
.muted { color: var(--muted); }

/* Resume Embed  */
.resume-embed {
  width: 100%;
  height: min(90vh, 1100px); /* tall but not too tall */
  border: 0;
  display: block;
}

/* Optional: for small screens, prefer shorter height */
@media (max-width: 640px) {
  .resume-embed { height: 75vh; }
}

/* Experience */
.timeline { position: relative; }
.timeline::before { content: ""; position: absolute; left: 14px; top: 0; bottom: 0; width: 2px; background: var(--border); }
.entry { position: relative; padding-left: 44px; margin: 0 0 1rem; }
.entry::before { content: ""; position: absolute; left: 8px; top: .3rem; width: 12px; height: 12px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px var(--accent-weak); }

/* Contact */
form { display: grid; gap: .75rem; }
input, textarea { width: 100%; padding: .8rem .9rem; border: 1px solid var(--border); background: var(--bg); color: var(--fg); border-radius: 12px; }
textarea { min-height: 140px; resize: vertical; }
.socials { display: flex; gap: .6rem; }

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

/* Utility */
.row { display: flex; align-items: center; gap: .6rem; flex-wrap: wrap; }
.center { text-align: center; }