/* ===========================================================
   Naveen Prakash R | Portfolio
   =========================================================== */

:root {
  --bg: #0b0f17;
  --bg-alt: #0f1521;
  --surface: #141b29;
  --surface-2: #1a2233;
  --border: #233047;
  --text: #e7ecf3;
  --text-dim: #9aa7bd;
  --text-faint: #6b7990;
  --accent: #5eead4;
  --accent-2: #818cf8;
  --accent-grad: linear-gradient(120deg, #5eead4 0%, #818cf8 100%);
  --shadow: 0 18px 40px -22px rgba(0, 0, 0, 0.8);
  --radius: 16px;
  --maxw: 1080px;
  --font-sans: "Inter", system-ui, -apple-system, sans-serif;
  --font-display: "Sora", var(--font-sans);
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
}

[data-theme="light"] {
  --bg: #f7f8fb;
  --bg-alt: #eef1f7;
  --surface: #ffffff;
  --surface-2: #f1f4fa;
  --border: #dde3ee;
  --text: #131925;
  --text-dim: #4a5568;
  --text-faint: #7a869c;
  --accent: #0d9488;
  --accent-2: #4f46e5;
  --accent-grad: linear-gradient(120deg, #0d9488 0%, #4f46e5 100%);
  --shadow: 0 18px 40px -26px rgba(20, 30, 60, 0.35);
}

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

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background 0.4s ease, color 0.4s ease;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }

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

.skip-link {
  position: absolute; left: -999px; top: 8px; z-index: 200;
  background: var(--accent); color: #04201c; padding: 10px 16px;
  border-radius: 8px; font-weight: 600;
}
.skip-link:focus { left: 12px; }

/* ===== Buttons ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px; font-weight: 600; font-size: 0.95rem;
  padding: 12px 22px; border-radius: 999px; cursor: pointer;
  border: 1px solid transparent; transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
  white-space: nowrap;
}
.btn--sm { padding: 8px 16px; font-size: 0.85rem; }
.btn--primary { background: var(--accent-grad); color: #06231e; box-shadow: 0 10px 24px -12px var(--accent); }
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 16px 30px -14px var(--accent); }
.btn--ghost { background: transparent; border-color: var(--border); color: var(--text); }
.btn--ghost:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }

.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; border-radius: 10px; cursor: pointer;
  background: transparent; border: 1px solid var(--border); color: var(--text);
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}
.icon-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ===== Nav ===== */
.nav {
  position: sticky; top: 0; z-index: 100;
  backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--bg) 78%, 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; gap: 20px;
}
.nav__brand { display: inline-flex; align-items: center; gap: 10px; }
.nav__logo { height: 34px; width: 34px; display: block; flex-shrink: 0; }
.nav__brand-text { font-family: var(--font-display); font-weight: 700; font-size: 1.05rem; letter-spacing: -0.4px; color: var(--text); }
.nav__links { display: flex; gap: 26px; margin-left: auto; }
.nav__links a {
  font-size: 0.92rem; color: var(--text-dim); font-weight: 500;
  position: relative; transition: color 0.2s ease;
}
.nav__links a::after {
  content: ""; position: absolute; left: 0; bottom: -6px; height: 2px; width: 0;
  background: var(--accent-grad); transition: width 0.25s ease;
}
.nav__links a:hover, .nav__links a.active { color: var(--text); }
.nav__links a:hover::after, .nav__links a.active::after { width: 100%; }
.nav__actions { display: flex; align-items: center; gap: 10px; }
.nav__burger { display: none; }

/* ===== Hero ===== */
.hero { position: relative; padding: clamp(80px, 16vh, 160px) 0 clamp(60px, 10vh, 110px); overflow: hidden; }
.hero__bg {
  position: absolute; inset: 0; z-index: 0;
  background:
    radial-gradient(60% 50% at 20% 10%, color-mix(in srgb, var(--accent) 22%, transparent), transparent 70%),
    radial-gradient(55% 50% at 85% 20%, color-mix(in srgb, var(--accent-2) 22%, transparent), transparent 70%);
  filter: blur(8px); opacity: 0.7;
}
.hero__inner { position: relative; z-index: 1; max-width: 860px; }
.hero__eyebrow {
  font-family: var(--font-mono); font-size: 0.85rem; letter-spacing: 1px;
  color: var(--accent); text-transform: uppercase; margin-bottom: 18px;
}
.hero__title {
  font-family: var(--font-display); font-weight: 800;
  font-size: clamp(2.6rem, 8vw, 5rem); line-height: 1.02;
  letter-spacing: -2px; margin-bottom: 22px;
  background: linear-gradient(180deg, var(--text), color-mix(in srgb, var(--text) 55%, var(--text-faint)));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero__lede { font-size: clamp(1.05rem, 2.4vw, 1.3rem); color: var(--text-dim); max-width: 680px; margin-bottom: 26px; }
.hero__lede strong { color: var(--text); font-weight: 600; }
.hero__meta { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 32px; }
.chip {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.82rem; color: var(--text-dim); background: var(--surface);
  border: 1px solid var(--border); padding: 7px 14px; border-radius: 999px;
}
.chip::before {
  content: ""; width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent); flex-shrink: 0;
}
.hero__cta { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 30px; }
.hero__social { display: flex; gap: 16px; align-items: center; color: var(--text-dim); }
.hero__social a { transition: color 0.2s ease, transform 0.2s ease; }
.hero__social a:hover { color: var(--accent); transform: translateY(-3px); }

/* ===== Section scaffolding ===== */
.section { padding: clamp(64px, 10vh, 110px) 0; }
.section--alt { background: var(--bg-alt); }
.section__head { display: flex; align-items: baseline; gap: 14px; margin-bottom: 44px; }
.section__head--center { flex-direction: column; align-items: center; text-align: center; gap: 6px; }
.section__num { font-family: var(--font-mono); color: var(--accent); font-size: 0.95rem; }
.section__title {
  font-family: var(--font-display); font-weight: 700;
  font-size: clamp(1.7rem, 4vw, 2.4rem); letter-spacing: -0.8px;
}

/* ===== About ===== */
.about { display: grid; grid-template-columns: 1.5fr 1fr; gap: 48px; align-items: start; }
.about__text p { color: var(--text-dim); margin-bottom: 18px; font-size: 1.05rem; }
.about__text strong { color: var(--text); font-weight: 600; }
.about__facts { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.fact {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 20px; text-align: left;
}
.fact__num {
  display: block; font-family: var(--font-display); font-weight: 800; font-size: 2rem;
  background: var(--accent-grad); -webkit-background-clip: text; background-clip: text; color: transparent;
}
.fact__label { font-size: 0.85rem; color: var(--text-dim); }

/* ===== Timeline ===== */
.timeline { list-style: none; position: relative; padding-left: 28px; }
.timeline::before {
  content: ""; position: absolute; left: 7px; top: 6px; bottom: 6px; width: 2px;
  background: linear-gradient(var(--accent), var(--accent-2), transparent);
}
.tl { position: relative; padding-bottom: 28px; }
.tl:last-child { padding-bottom: 0; }
.tl__dot {
  position: absolute; left: -28px; top: 24px; width: 16px; height: 16px; border-radius: 50%;
  background: var(--bg); border: 3px solid var(--accent); box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 18%, transparent);
}
.tl__card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px 26px; box-shadow: var(--shadow); transition: transform 0.25s ease, border-color 0.25s ease;
}
.tl__card:hover { transform: translateX(4px); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.tl__top { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 6px; margin-bottom: 14px; }
.tl__role { font-family: var(--font-display); font-size: 1.15rem; font-weight: 600; }
.tl__role span { color: var(--text-dim); font-weight: 400; font-size: 0.95rem; font-family: var(--font-sans); }
.tl__date { font-family: var(--font-mono); font-size: 0.82rem; color: var(--accent); white-space: nowrap; }
.tl__points { list-style: none; display: flex; flex-direction: column; gap: 10px; margin-bottom: 16px; }
.tl__points li { position: relative; padding-left: 20px; color: var(--text-dim); font-size: 0.97rem; }
.tl__points li::before { content: "▹"; position: absolute; left: 0; color: var(--accent); }
.tl__points strong { color: var(--text); font-weight: 600; }

/* ===== Tags ===== */
.tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  font-family: var(--font-mono); font-size: 0.74rem; color: var(--text-dim);
  background: var(--surface-2); border: 1px solid var(--border); border-radius: 6px; padding: 4px 9px;
}

/* ===== Education ===== */
.edu { margin-top: 48px; }
.edu__title { font-family: var(--font-display); font-size: 1.2rem; margin-bottom: 18px; }
.edu__grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.edu__item {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px 22px; display: flex; flex-direction: column; gap: 4px;
}
.edu__item .edu__date { font-family: var(--font-mono); font-size: 0.78rem; color: var(--accent); }
.edu__item strong { font-size: 1.02rem; }
.edu__item > span:last-of-type { color: var(--text-dim); font-size: 0.92rem; }
.edu__thesis { margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 10px; }
.edu__thesis h4 { font-family: var(--font-display); font-size: 0.95rem; font-weight: 600; color: var(--text); }
.edu__thesis ul { list-style: none; display: flex; flex-direction: column; gap: 7px; }
.edu__thesis li { position: relative; padding-left: 18px; color: var(--text-dim); font-size: 0.9rem; }
.edu__thesis li::before { content: "▹"; position: absolute; left: 0; color: var(--accent); }
.edu__thesis a { color: var(--accent); font-weight: 500; }
.edu__thesis a:hover { text-decoration: underline; }

/* ===== Projects ===== */
.projects { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow);
  transition: transform 0.25s ease, border-color 0.25s ease;
  display: flex; flex-direction: column; gap: 14px;
}
.card:hover { transform: translateY(-5px); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.card__kicker {
  font-family: var(--font-mono); font-size: 0.72rem; font-weight: 500;
  letter-spacing: 1.5px; text-transform: uppercase; color: var(--accent);
}
.card__title { font-family: var(--font-display); font-size: 1.18rem; font-weight: 600; line-height: 1.3; }
.card__tag-inline { color: var(--accent); font-weight: 500; font-size: 0.9rem; }
.card__desc { color: var(--text-dim); font-size: 0.95rem; }
.card__desc strong { color: var(--text); font-weight: 600; }
.card__desc code { font-family: var(--font-mono); font-size: 0.85em; background: var(--surface-2); padding: 1px 6px; border-radius: 5px; color: var(--accent); }
.card .tags { margin-top: auto; }
.card__link {
  font-family: var(--font-mono); font-size: 0.82rem; font-weight: 500;
  color: var(--accent); align-self: flex-start; transition: gap 0.2s ease, opacity 0.2s ease;
}
.card__link:hover { opacity: 0.8; text-decoration: underline; }

/* ===== Repos (Also on GitHub) ===== */
.repos { margin-top: 48px; }
.repos__head { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 8px; margin-bottom: 20px; }
.repos__head h3 { font-family: var(--font-display); font-size: 1.2rem; }
.repos__head h3::before { content: "// "; color: var(--accent); font-family: var(--font-mono); }
.repos__all { font-family: var(--font-mono); font-size: 0.84rem; color: var(--accent); }
.repos__all:hover { text-decoration: underline; }
.repo-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.repo {
  display: flex; flex-direction: column; gap: 10px;
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px; transition: transform 0.22s ease, border-color 0.22s ease;
}
.repo:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.repo__name { font-family: var(--font-display); font-weight: 600; font-size: 0.98rem; word-break: break-word; }
.repo__desc { color: var(--text-dim); font-size: 0.88rem; }
.repo .tags { gap: 6px; }
.repo .tag { font-size: 0.68rem; padding: 3px 7px; }
.repo__lang { display: flex; align-items: center; gap: 7px; font-size: 0.8rem; color: var(--text-faint); margin-top: auto; padding-top: 2px; }
.repo__lang i { width: 11px; height: 11px; border-radius: 50%; display: inline-block; }

/* ===== Skills ===== */
.skills { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.skillset { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px 24px; }
.skillset h3 { font-family: var(--font-display); font-size: 1.02rem; margin-bottom: 14px; color: var(--text); }
.skillset h3::before { content: "// "; color: var(--accent); font-family: var(--font-mono); }

/* ===== Achievements ===== */
.achievements { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.ach {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 24px; display: flex; gap: 16px; align-items: flex-start;
  transition: border-color 0.25s ease, transform 0.25s ease;
}
.ach:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); }
.ach__icon {
  flex-shrink: 0; width: 42px; height: 42px; border-radius: 11px;
  display: inline-flex; align-items: center; justify-content: center;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, var(--border));
  color: var(--accent);
}
.ach__icon svg { width: 21px; height: 21px; }
.ach h3 { font-family: var(--font-display); font-size: 1.02rem; margin-bottom: 6px; }
.ach p { color: var(--text-dim); font-size: 0.92rem; }
.ach a { color: var(--accent); font-weight: 500; }
.ach a:hover { text-decoration: underline; }

/* ===== Contact ===== */
.contact { text-align: center; }
.contact__lede { color: var(--text-dim); max-width: 560px; margin: 0 auto 30px; font-size: 1.05rem; }
.contact__actions { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }

/* ===== Footer ===== */
.footer { border-top: 1px solid var(--border); padding: 28px 0; }
.footer__inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; color: var(--text-faint); font-size: 0.85rem; }

/* ===== Reveal animation ===== */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .nav__links {
    position: fixed; inset: 64px 0 auto 0; flex-direction: column; gap: 0;
    background: var(--bg-alt); border-bottom: 1px solid var(--border);
    padding: 8px 24px 18px; transform: translateY(-130%); transition: transform 0.3s ease; margin-left: 0;
  }
  .nav__links.open { transform: translateY(0); }
  .nav__links a { padding: 12px 0; border-bottom: 1px solid var(--border); }
  .nav__burger { display: inline-flex; }
  .nav__actions .btn--ghost { display: none; }
  .about { grid-template-columns: 1fr; gap: 28px; }
  .projects, .skills, .achievements, .edu__grid { grid-template-columns: 1fr; }
  .repo-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 560px) {
  .repo-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .about__facts { grid-template-columns: 1fr 1fr; }
  .tl__card, .card, .skillset, .ach { padding: 18px; }
  .nav__brand-text { display: none; }
}