/* =========================================================
   Siddharth Shukla — Portfolio
   Light default + dark toggle. No build step, vanilla CSS.
   ========================================================= */

:root {
  --navy: #1b3a5c;
  --blue: #2e75b6;
  --accent: #2e75b6;
  --accent-soft: #eaf1fa;

  --bg: #ffffff;
  --bg-alt: #f5f8fc;
  --surface: #ffffff;
  --surface-2: #f0f5fb;
  --border: #e2e8f0;
  --text: #1a2330;
  --text-soft: #4a5568;
  --text-faint: #6b7790;
  --heading: #15293f;
  --shadow: 0 1px 2px rgba(16, 38, 66, .04), 0 8px 24px rgba(16, 38, 66, .06);
  --shadow-hover: 0 4px 12px rgba(16, 38, 66, .08), 0 18px 40px rgba(16, 38, 66, .12);
}

html[data-theme="dark"] {
  --navy: #0b1220;
  --blue: #5aa9ff;
  --accent: #6db4ff;
  --accent-soft: #16243a;

  --bg: #0a0f1a;
  --bg-alt: #0d1422;
  --surface: #111a2b;
  --surface-2: #16203400;
  --border: #1f2c44;
  --text: #e6edf6;
  --text-soft: #aab7c9;
  --text-faint: #7e8da3;
  --heading: #f2f6fc;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 10px 30px rgba(0, 0, 0, .35);
  --shadow-hover: 0 6px 18px rgba(0, 0, 0, .4), 0 24px 50px rgba(0, 0, 0, .5);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background .35s ease, color .35s ease;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 1040px; margin: 0 auto; padding: 0 24px; }

section { padding: 76px 0; }

.eyebrow {
  font-size: .78rem; font-weight: 700; letter-spacing: .14em; text-transform: uppercase;
  color: var(--blue); margin-bottom: 10px;
}
.section-title {
  font-size: clamp(1.5rem, 3.2vw, 2rem);
  color: var(--heading);
  letter-spacing: -.025em;
  margin-bottom: 8px;
}
.section-sub { color: var(--text-faint); margin-bottom: 40px; font-size: 1rem; max-width: 620px; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1040px; margin: 0 auto; padding: 12px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { font-weight: 700; color: var(--heading); letter-spacing: -.01em; font-size: 1.02rem; }
.brand span { color: var(--blue); }
.nav-links { display: flex; gap: 24px; align-items: center; }
.nav-links a { color: var(--text-soft); font-size: .92rem; font-weight: 500; }
.nav-links a:hover { color: var(--accent); text-decoration: none; }

.theme-toggle {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  width: 38px; height: 38px; border-radius: 10px;
  cursor: pointer; font-size: 1.05rem; line-height: 1;
  display: inline-flex; align-items: center; justify-content: center;
  transition: background .2s, transform .2s, border-color .2s;
}
.theme-toggle:hover { transform: translateY(-1px); border-color: var(--blue); }

@media (max-width: 680px) { .nav-links a:not(.theme-toggle) { display: none; } }

/* ---------- Hero ---------- */
.hero { padding: 104px 0 72px; position: relative; overflow: hidden; }
.hero::after {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(680px 360px at 8% -10%, var(--accent-soft), transparent 70%),
    radial-gradient(560px 320px at 98% 8%, var(--accent-soft), transparent 72%);
  opacity: .95;
}
.hero .available {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: .82rem; font-weight: 600; color: var(--text-soft);
  background: var(--surface); border: 1px solid var(--border);
  padding: 6px 14px; border-radius: 999px; box-shadow: var(--shadow); margin-bottom: 24px;
}
.dot { width: 8px; height: 8px; border-radius: 50%; background: #22c55e; box-shadow: 0 0 0 3px rgba(34,197,94,.18); }

.hero h1 {
  font-size: clamp(2.4rem, 7vw, 4.2rem);
  color: var(--heading); letter-spacing: -.04em; line-height: 1.02; font-weight: 800;
}
.hero h1 .grad {
  background: linear-gradient(120deg, var(--navy), var(--blue));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
html[data-theme="dark"] .hero h1 .grad {
  background: linear-gradient(120deg, #8fc6ff, var(--blue));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero .role { color: var(--blue); font-weight: 600; font-size: clamp(1.05rem, 2.4vw, 1.35rem); margin-top: 14px; }
.hero .blurb { color: var(--text-soft); margin-top: 18px; max-width: 660px; font-size: 1.1rem; }

.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 20px; border-radius: 11px; font-weight: 600; font-size: .94rem;
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  transition: transform .18s, box-shadow .18s, border-color .18s, background .18s;
}
.btn:hover { transform: translateY(-2px); box-shadow: var(--shadow); text-decoration: none; border-color: var(--blue); }
.btn-primary { background: linear-gradient(145deg, var(--navy), var(--blue)); color: #fff; border-color: transparent; }
.btn-primary:hover { color: #fff; box-shadow: var(--shadow-hover); }

/* ---------- Marquee skills strip under hero ---------- */
.focus-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 38px; }
.focus-chip {
  font-size: .86rem; font-weight: 600; color: var(--text-soft);
  background: var(--surface-2); border: 1px solid var(--border);
  padding: 7px 14px; border-radius: 10px;
}
.focus-chip b { color: var(--blue); }

/* ---------- About ---------- */
.about-line {
  font-size: clamp(1.25rem, 2.8vw, 1.7rem); line-height: 1.5; color: var(--heading);
  letter-spacing: -.01em; max-width: 880px; font-weight: 500;
}
.about-line strong { color: var(--blue); font-weight: 700; }

/* ---------- Projects ---------- */
.proj-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 22px; }

.proj-card {
  display: flex; flex-direction: column;
  background: var(--surface); border: 1px solid var(--border); border-radius: 18px;
  padding: 28px; box-shadow: var(--shadow);
  position: relative; overflow: hidden;
  transition: transform .22s, box-shadow .22s, border-color .22s;
}
.proj-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); border-color: color-mix(in srgb, var(--blue) 50%, var(--border)); }

.proj-top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; }
.proj-index {
  font-size: .8rem; font-weight: 700; color: var(--text-faint); letter-spacing: .1em;
}
.pill {
  font-size: .68rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase;
  color: var(--blue); background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--blue) 28%, transparent);
  padding: 4px 10px; border-radius: 999px;
}
.proj-card h3 { font-size: 1.32rem; color: var(--heading); margin-bottom: 8px; letter-spacing: -.01em; }
.proj-card .stack { color: var(--blue); font-size: .82rem; font-weight: 600; margin-bottom: 14px; }
.proj-card p { color: var(--text-soft); font-size: .96rem; flex: 1; }
.proj-links { display: flex; gap: 18px; margin-top: 22px; flex-wrap: wrap; }
.proj-links a { font-size: .9rem; font-weight: 600; display: inline-flex; align-items: center; gap: 5px; }
.proj-links a:hover { text-decoration: none; transform: translateX(1px); }

/* compact cards for the professional "selected work" row */
.work-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 18px; }
.work-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
  padding: 22px 24px; box-shadow: var(--shadow);
  border-left: 4px solid; border-left-color: var(--blue);
  transition: transform .2s, box-shadow .2s;
}
.work-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.work-card h3 { font-size: 1.1rem; color: var(--heading); margin-bottom: 4px; }
.work-card .stack { color: var(--blue); font-size: .78rem; font-weight: 600; margin-bottom: 10px; }
.work-card p { color: var(--text-soft); font-size: .92rem; }

/* ---------- Skills ---------- */
.skill-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 16px; }
.skill-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
  padding: 22px; box-shadow: var(--shadow);
  transition: transform .2s, box-shadow .2s, border-color .2s;
}
.skill-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: color-mix(in srgb, var(--blue) 40%, var(--border)); }
.skill-card h3 {
  font-size: .82rem; text-transform: uppercase; letter-spacing: .08em;
  color: var(--blue); margin-bottom: 14px;
}
.tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  font-size: .82rem; padding: 5px 11px; border-radius: 999px;
  background: var(--surface-2); color: var(--text-soft); border: 1px solid var(--border);
}

/* ---------- Contact ---------- */
.contact { text-align: center; }
.contact .eyebrow { text-align: center; }
.contact .section-title { font-size: clamp(1.8rem, 4vw, 2.6rem); }
.contact p { color: var(--text-soft); max-width: 560px; margin: 0 auto 30px; font-size: 1.05rem; }
.contact-links { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--border); padding: 30px 0;
  text-align: center; color: var(--text-faint); font-size: .86rem;
}

/* reveal-on-scroll */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}