/* ============================================================
   Vijay Nelakurthi — Portfolio
   Design tokens
   ============================================================ */
:root {
  --bg: #0b0f14;
  --bg-alt: #0f151c;
  --surface: #121a23;
  --surface-2: #16212c;
  --border: #1f2c39;
  --text: #e7eef5;
  --muted: #93a4b5;
  --faint: #62707e;
  --accent: #3ddc97;
  --accent-2: #635bff;
  --accent-soft: rgba(61, 220, 151, 0.12);
  --grad: linear-gradient(110deg, #3ddc97 0%, #5ee6e0 45%, #635bff 100%);
  --radius: 16px;
  --radius-sm: 10px;
  --maxw: 1120px;
  --shadow: 0 20px 50px -20px rgba(0, 0, 0, 0.6);
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

[data-theme="light"] {
  --bg: #f7f9fb;
  --bg-alt: #eef2f6;
  --surface: #ffffff;
  --surface-2: #f3f6f9;
  --border: #e1e8ef;
  --text: #14202b;
  --muted: #51606f;
  --faint: #8294a4;
  --accent: #0f9d63;
  --accent-2: #5046e5;
  --accent-soft: rgba(15, 157, 99, 0.1);
  --shadow: 0 20px 50px -24px rgba(20, 40, 60, 0.25);
}

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

html { scroll-behavior: smooth; scroll-padding-top: 88px; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  transition: background 0.3s ease, color 0.3s ease;
}

a { color: var(--accent); text-decoration: none; transition: color 0.2s ease; }
a:hover { color: var(--text); }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

.grad {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ============================================================ Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn--primary {
  background: var(--grad);
  color: #04110b;
  box-shadow: 0 10px 30px -10px rgba(61, 220, 151, 0.5);
}
.btn--primary:hover { color: #04110b; box-shadow: 0 16px 40px -10px rgba(61, 220, 151, 0.6); }
.btn--ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn--ghost:hover { border-color: var(--accent); color: var(--accent); }

/* ============================================================ Nav */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--bg) 72%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease;
}
.nav.scrolled { border-bottom-color: var(--border); }
.nav__inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}
.nav__brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; }
.nav__logo {
  display: grid; place-items: center;
  width: 34px; height: 34px;
  border-radius: 9px;
  background: var(--grad);
  color: #04110b;
  font-weight: 800;
  font-size: 0.85rem;
}
.nav__name { font-size: 0.98rem; }
.nav__links { display: flex; gap: 26px; }
.nav__links a { color: var(--muted); font-size: 0.92rem; font-weight: 500; }
.nav__links a:hover { color: var(--text); }
.nav__cta { display: flex; align-items: center; gap: 12px; }
.theme-toggle {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  width: 38px; height: 38px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 1.1rem;
  transition: border-color 0.2s ease, transform 0.15s ease;
}
.theme-toggle:hover { border-color: var(--accent); transform: rotate(20deg); }

@media (max-width: 760px) {
  .nav__links { display: none; }
  .nav__name { display: none; }
}

/* ============================================================ Hero */
.hero {
  position: relative;
  padding: 170px 0 90px;
  overflow: hidden;
}
.hero__bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(60% 50% at 15% 10%, rgba(61, 220, 151, 0.14), transparent 60%),
    radial-gradient(55% 45% at 85% 0%, rgba(99, 91, 255, 0.16), transparent 55%);
  pointer-events: none;
}
.hero__inner { position: relative; }
.hero__eyebrow {
  font-family: var(--mono);
  color: var(--accent);
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 22px;
}
.hero__title {
  font-size: clamp(2.2rem, 6vw, 4rem);
  line-height: 1.08;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 26px;
}
.hero__lede {
  font-size: clamp(1.02rem, 2vw, 1.22rem);
  color: var(--muted);
  max-width: 720px;
  margin-bottom: 34px;
}
.hero__lede strong { color: var(--text); }
.hero__actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 30px; }
.hero__meta {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--faint);
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}
.hero__meta a { color: var(--muted); }
.hero__meta a:hover { color: var(--accent); }
.dot { color: var(--faint); }

/* ============================================================ Metrics */
.metrics { padding: 10px 0 30px; }
.metrics__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.metric {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 22px;
}
.metric__num {
  display: block;
  font-size: 2.1rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.metric__label { color: var(--muted); font-size: 0.9rem; }
@media (max-width: 760px) {
  .metrics__grid { grid-template-columns: repeat(2, 1fr); }
}

/* ============================================================ Sections */
.section { padding: 88px 0; }
.section--alt { background: var(--bg-alt); }
.section__head { max-width: 720px; margin-bottom: 50px; }
.section__kicker {
  font-family: var(--mono);
  color: var(--accent);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 12px;
}
.section__title {
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
}
.section__sub { color: var(--muted); margin-top: 14px; font-size: 1.05rem; }

.grid-2 { display: grid; grid-template-columns: 0.85fr 1.15fr; gap: 50px; align-items: start; }
@media (max-width: 860px) { .grid-2 { grid-template-columns: 1fr; gap: 24px; } }

.about__body p { color: var(--muted); margin-bottom: 18px; font-size: 1.05rem; }
.about__body strong { color: var(--text); }
.about__tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 26px;
}
.about__tags li {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
  padding: 6px 12px;
  border-radius: 999px;
}

/* ============================================================ Skills */
.skills__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
@media (max-width: 760px) { .skills__grid { grid-template-columns: 1fr; } }
.skillcard {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.25s ease;
}
.skillcard:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); box-shadow: var(--shadow); }
.skillcard__icon { font-size: 1.6rem; margin-bottom: 14px; }
.skillcard h3 { font-size: 1.2rem; margin-bottom: 8px; }
.skillcard > p { color: var(--muted); font-size: 0.95rem; margin-bottom: 18px; }
.chips { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; }
.chips li {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--muted);
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 5px 10px;
  border-radius: 7px;
}

/* ============================================================ Work */
.work__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
@media (max-width: 860px) { .work__grid { grid-template-columns: 1fr; } }
.project {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  position: relative;
  overflow: hidden;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.25s ease;
}
.project::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--grad);
  opacity: 0;
  transition: opacity 0.25s ease;
}
.project:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: color-mix(in srgb, var(--accent) 35%, var(--border)); }
.project:hover::before { opacity: 1; }
.project__head { display: flex; flex-direction: column; gap: 6px; margin-bottom: 14px; }
.project__head h3 { font-size: 1.3rem; }
.project__tag { font-family: var(--mono); font-size: 0.74rem; color: var(--accent); }
.project > p { color: var(--muted); font-size: 0.97rem; margin-bottom: 16px; }
.project > p strong { color: var(--text); }
.project__points { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.project__points li {
  color: var(--muted);
  font-size: 0.9rem;
  padding-left: 20px;
  position: relative;
}
.project__points li::before {
  content: "▹";
  position: absolute; left: 0;
  color: var(--accent);
}
.work__note { margin-top: 34px; text-align: center; }
.link-arrow { font-family: var(--mono); font-weight: 600; }

/* ============================================================ Impact */
.impact__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
@media (max-width: 860px) { .impact__grid { grid-template-columns: 1fr; } }
.impact {
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 24px;
  background: var(--surface);
}
.impact h3 { font-size: 1.08rem; margin-bottom: 8px; }
.impact p { color: var(--muted); font-size: 0.93rem; }

/* ============================================================ Writing */
.writing__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
@media (max-width: 760px) { .writing__grid { grid-template-columns: 1fr; } }
.post {
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 22px 24px;
  transition: transform 0.18s ease, border-color 0.2s ease;
}
.post:hover { transform: translateX(4px); border-color: var(--accent); }
.post h3 { font-size: 1.05rem; color: var(--text); }
.post span { font-family: var(--mono); font-size: 0.75rem; color: var(--faint); }

/* ============================================================ CTA */
.section--cta { text-align: center; }
.cta__inner {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 60px 30px;
  position: relative;
  overflow: hidden;
}
.cta__inner::after {
  content: "";
  position: absolute; inset: 0;
  background: radial-gradient(60% 100% at 50% 0%, rgba(61, 220, 151, 0.1), transparent 70%);
  pointer-events: none;
}
.cta__title { font-size: clamp(1.8rem, 4vw, 2.6rem); font-weight: 800; letter-spacing: -0.02em; }
.cta__sub { color: var(--muted); max-width: 520px; margin: 14px auto 28px; }
.cta__actions { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }

/* ============================================================ Footer */
.footer { border-top: 1px solid var(--border); padding: 30px 0; }
.footer__inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  color: var(--faint);
  font-size: 0.85rem;
}
.footer__meta a { color: var(--muted); }
.fineprint { display: block; color: var(--faint); font-size: 0.75rem; padding-bottom: 30px; }

/* ============================================================ Reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1), transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}