/* ============================================================
   Saurabh Verma · AI Systems Portfolio
   Dark, engineering-forward. Emerald accent nods to brand.
   ============================================================ */

:root {
  --bg:        #080b10;
  --bg2:       #0d1119;
  --panel:     #10151f;
  --panel2:    #141b27;
  --border:    rgba(120,160,150,.14);
  --border2:   rgba(120,160,150,.24);
  --grid:      rgba(120,160,150,.05);

  --emerald:   #34d399;
  --emerald-d: #10b981;
  --cyan:      #38bdf8;
  --amber:     #f4b860;

  --text:      #e6eef0;
  --muted:     #93a7a0;
  --dim:       #5f736c;

  --mono:      'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans:      'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --body:      'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --radius:    14px;
  --radius-lg: 20px;
  --shadow:    0 8px 40px rgba(0,0,0,.45);
  --glow:      0 0 0 1px rgba(52,211,153,.25), 0 8px 40px rgba(52,211,153,.08);
  --trans:     .22s cubic-bezier(.4,0,.2,1);
  --max:       1180px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; -webkit-text-size-adjust: 100%; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--body);
  line-height: 1.65;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(900px 500px at 82% -8%, rgba(52,211,153,.09), transparent 60%),
    radial-gradient(760px 460px at 8% 8%, rgba(56,189,248,.06), transparent 55%);
  background-repeat: no-repeat;
}
a { color: var(--emerald); text-decoration: none; transition: color var(--trans); }
a:hover { color: var(--cyan); }
img { max-width: 100%; display: block; }
ul { list-style: none; }
::selection { background: rgba(52,211,153,.28); color: #fff; }

h1, h2, h3, h4 { font-family: var(--sans); line-height: 1.15; font-weight: 600; letter-spacing: -.02em; }
h1 { font-size: clamp(2.4rem, 6vw, 4.2rem); font-weight: 700; }
h2 { font-size: clamp(1.7rem, 3.4vw, 2.6rem); }
h3 { font-size: 1.28rem; }

/* ── layout ── */
.container { max-width: var(--max); margin: 0 auto; padding: 0 1.6rem; }
section { position: relative; }
.sec { padding: clamp(4.5rem, 9vw, 7.5rem) 0; }

.eyebrow {
  font-family: var(--mono);
  font-size: .74rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--emerald);
  display: inline-flex;
  align-items: center;
  gap: .55rem;
}
.eyebrow::before {
  content: '';
  width: 26px; height: 1px;
  background: linear-gradient(90deg, var(--emerald), transparent);
}
.sec-head { max-width: 720px; margin-bottom: 3rem; }
.sec-head h2 { margin: .9rem 0 .8rem; }
.sec-head p { color: var(--muted); font-size: 1.06rem; }

/* ── nav ── */
#nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(8,11,16,.72);
  backdrop-filter: blur(16px) saturate(140%);
  border-bottom: 1px solid transparent;
  transition: border-color var(--trans), background var(--trans);
}
#nav.scrolled { border-bottom-color: var(--border); background: rgba(8,11,16,.9); }
.nav-inner {
  max-width: var(--max); margin: 0 auto; padding: .95rem 1.6rem;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-logo {
  font-family: var(--mono); font-weight: 700; font-size: 1.02rem;
  color: var(--text); letter-spacing: -.02em;
}
.nav-logo b { color: var(--emerald); }
.nav-links { display: flex; gap: 2rem; align-items: center; }
.nav-links a {
  font-family: var(--mono); font-size: .82rem; color: var(--muted);
  letter-spacing: .02em; position: relative;
}
.nav-links a::after {
  content: ''; position: absolute; left: 0; bottom: -5px; height: 1px; width: 0;
  background: var(--emerald); transition: width var(--trans);
}
.nav-links a:hover { color: var(--text); }
.nav-links a:hover::after { width: 100%; }
.nav-cta {
  font-family: var(--mono); font-size: .8rem;
  border: 1px solid var(--border2); border-radius: 8px;
  padding: .45rem .95rem !important; color: var(--text) !important;
  transition: all var(--trans);
}
.nav-cta:hover { border-color: var(--emerald); background: rgba(52,211,153,.08); }
.nav-cta::after { display: none; }
.nav-toggle { display: none; background: none; border: 0; color: var(--text); cursor: pointer; font-size: 1.5rem; }

/* ── hero ── */
#hero { padding: 9.5rem 0 5rem; position: relative; overflow: hidden; }
.hero-grid {
  position: absolute; inset: 0; z-index: 0;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(700px 500px at 70% 30%, #000 20%, transparent 78%);
}
.hero-inner {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 1.55fr .95fr; gap: 3.5rem; align-items: center;
}
.hero-status {
  display: inline-flex; align-items: center; gap: .55rem;
  font-family: var(--mono); font-size: .76rem; color: var(--muted);
  border: 1px solid var(--border); border-radius: 100px;
  padding: .4rem .9rem; margin-bottom: 1.7rem;
}
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--emerald); box-shadow: 0 0 0 0 rgba(52,211,153,.5); animation: pulse 2.2s infinite; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 rgba(52,211,153,.5); } 70% { box-shadow: 0 0 0 8px rgba(52,211,153,0); } 100% { box-shadow: 0 0 0 0 rgba(52,211,153,0); } }

.hero-inner h1 { margin-bottom: 1.1rem; }
.hero-inner h1 .grad {
  background: linear-gradient(120deg, var(--emerald), var(--cyan));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-lead { font-size: 1.18rem; color: var(--muted); max-width: 40rem; margin-bottom: 1.4rem; }
.hero-lead strong { color: var(--text); font-weight: 600; }
.hero-tags { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 2rem; }
.tag {
  font-family: var(--mono); font-size: .74rem; color: var(--muted);
  border: 1px solid var(--border); border-radius: 7px; padding: .32rem .7rem;
  background: var(--panel);
}
.hero-actions { display: flex; flex-wrap: wrap; gap: .9rem; }
.btn {
  font-family: var(--mono); font-size: .86rem; font-weight: 500;
  padding: .8rem 1.5rem; border-radius: 10px; cursor: pointer;
  display: inline-flex; align-items: center; gap: .5rem;
  transition: all var(--trans); border: 1px solid transparent;
}
.btn-primary { background: var(--emerald); color: #052e22; font-weight: 600; }
.btn-primary:hover { background: var(--emerald-d); color: #042319; transform: translateY(-2px); box-shadow: 0 10px 30px rgba(52,211,153,.25); }
.btn-ghost { border-color: var(--border2); color: var(--text); background: var(--panel); }
.btn-ghost:hover { border-color: var(--emerald); color: var(--emerald); transform: translateY(-2px); }

/* hero terminal card */
.hero-card {
  background: linear-gradient(180deg, var(--panel), var(--bg2));
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  box-shadow: var(--shadow); overflow: hidden;
}
.term-bar { display: flex; align-items: center; gap: .5rem; padding: .8rem 1rem; border-bottom: 1px solid var(--border); background: rgba(255,255,255,.02); }
.term-bar span { width: 11px; height: 11px; border-radius: 50%; background: #2b3440; }
.term-bar span:nth-child(1) { background: #ff5f57; }
.term-bar span:nth-child(2) { background: #febc2e; }
.term-bar span:nth-child(3) { background: #28c840; }
.term-bar .term-title { width: auto; height: auto; background: none; margin-left: auto; font-family: var(--mono); font-size: .72rem; color: var(--dim); border-radius: 0; }
.term-body { padding: 1.15rem 1.2rem; font-family: var(--mono); font-size: .82rem; line-height: 1.9; }
.term-body .l { color: var(--muted); }
.term-body .k { color: var(--cyan); }
.term-body .v { color: var(--text); }
.term-body .g { color: var(--emerald); }
.term-body .c { color: var(--dim); }
.term-body .prompt { color: var(--emerald); }
.cursor { display: inline-block; width: 8px; height: 1.05em; background: var(--emerald); vertical-align: -2px; animation: blink 1.1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }

/* ── stat strip ── */
.stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0;
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--panel); overflow: hidden; margin-top: 3.2rem;
}
.stat { padding: 1.5rem 1.3rem; border-right: 1px solid var(--border); }
.stat:last-child { border-right: 0; }
.stat .num { font-family: var(--sans); font-size: 2rem; font-weight: 700; color: var(--text); letter-spacing: -.03em; }
.stat .num .u { color: var(--emerald); }
.stat .lbl { font-family: var(--mono); font-size: .72rem; color: var(--muted); text-transform: uppercase; letter-spacing: .08em; margin-top: .25rem; }

/* ── thesis ── */
#thesis .thesis-body { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; align-items: start; }
.thesis-body p { color: var(--muted); font-size: 1.08rem; margin-bottom: 1.1rem; }
.thesis-body p strong { color: var(--text); }
.model-line {
  font-family: var(--mono); font-size: .82rem; color: var(--muted);
  border-left: 2px solid var(--emerald); padding: .3rem 0 .3rem 1rem; margin: 1.3rem 0;
  line-height: 2;
}
.model-line b { color: var(--emerald); font-weight: 500; }

/* ── projects ── */
.projects { display: flex; flex-direction: column; gap: 1.6rem; }
.project {
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  background: linear-gradient(180deg, var(--panel), var(--bg2));
  padding: 2.1rem 2.1rem 1.9rem; transition: border-color var(--trans), transform var(--trans);
  position: relative; overflow: hidden;
}
.project::before {
  content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: linear-gradient(var(--emerald), var(--cyan)); opacity: .5; transition: opacity var(--trans);
}
.project:hover { border-color: var(--border2); transform: translateY(-3px); }
.project:hover::before { opacity: 1; }
.project-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.project-id { font-family: var(--mono); font-size: .74rem; color: var(--dim); letter-spacing: .1em; }
.project h3 { font-size: 1.5rem; margin: .35rem 0 .2rem; }
.project .role { font-family: var(--mono); font-size: .78rem; color: var(--emerald); }
.project-status {
  font-family: var(--mono); font-size: .72rem; color: var(--emerald);
  border: 1px solid rgba(52,211,153,.3); border-radius: 100px; padding: .3rem .8rem;
  display: inline-flex; align-items: center; gap: .45rem; white-space: nowrap; background: rgba(52,211,153,.06);
}
.project-status.wip { color: var(--amber); border-color: rgba(244,184,96,.3); background: rgba(244,184,96,.06); }
.project-desc { color: var(--muted); margin: 1.1rem 0 1.3rem; font-size: 1.02rem; max-width: 60rem; }
.project-desc strong { color: var(--text); }

.project-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 1.8rem; }
.pg-block h4 { font-family: var(--mono); font-size: .74rem; text-transform: uppercase; letter-spacing: .1em; color: var(--dim); margin-bottom: .7rem; }
.feat-list li { position: relative; padding-left: 1.4rem; color: var(--muted); font-size: .95rem; margin-bottom: .55rem; }
.feat-list li::before { content: '→'; position: absolute; left: 0; color: var(--emerald); font-family: var(--mono); }
.feat-list li b { color: var(--text); font-weight: 600; }

.metrics { display: grid; grid-template-columns: 1fr 1fr; gap: .7rem; margin-bottom: 1.3rem; }
.metric { border: 1px solid var(--border); border-radius: 10px; padding: .8rem .9rem; background: rgba(255,255,255,.015); }
.metric .m-num { font-family: var(--sans); font-size: 1.35rem; font-weight: 700; color: var(--emerald); letter-spacing: -.02em; }
.metric .m-lbl { font-family: var(--mono); font-size: .68rem; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; margin-top: .1rem; }
.stack { display: flex; flex-wrap: wrap; gap: .4rem; }
.stack span { font-family: var(--mono); font-size: .72rem; color: var(--muted); border: 1px solid var(--border); border-radius: 6px; padding: .25rem .6rem; }
.project-link { font-family: var(--mono); font-size: .8rem; margin-top: 1.4rem; display: inline-flex; align-items: center; gap: .4rem; }

/* ── architecture ── */
#architecture { background: var(--bg2); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.arch-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; align-items: center; }
.arch-diagram {
  border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--panel);
  padding: 1.4rem; font-family: var(--mono); font-size: .78rem; box-shadow: var(--shadow);
}
.arch-row { display: flex; align-items: center; gap: .7rem; padding: .55rem .2rem; }
.arch-node {
  flex: 1; border: 1px solid var(--border2); border-radius: 9px; padding: .6rem .8rem;
  background: var(--panel2); color: var(--text); display: flex; align-items: center; justify-content: space-between; gap: .5rem;
}
.arch-node small { color: var(--dim); font-size: .68rem; }
.arch-node.accent { border-color: rgba(52,211,153,.4); background: rgba(52,211,153,.06); }
.arch-node.accent b { color: var(--emerald); }
.arch-arrow { color: var(--dim); text-align: center; padding: .1rem 0; font-size: .8rem; }
.arch-legend { display: flex; flex-direction: column; gap: 1rem; }
.arch-legend .li { display: flex; gap: .9rem; align-items: flex-start; }
.arch-legend .li .ic { font-family: var(--mono); color: var(--emerald); font-size: .9rem; margin-top: .1rem; min-width: 22px; }
.arch-legend .li h4 { font-size: .98rem; margin-bottom: .15rem; }
.arch-legend .li p { color: var(--muted); font-size: .9rem; margin: 0; }

/* ── capabilities ── */
.cap-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.cap {
  border: 1px solid var(--border); border-radius: var(--radius); background: var(--panel);
  padding: 1.3rem 1.2rem; transition: border-color var(--trans), transform var(--trans);
}
.cap:hover { border-color: var(--border2); transform: translateY(-2px); }
.cap h4 { font-family: var(--mono); font-size: .78rem; text-transform: uppercase; letter-spacing: .08em; color: var(--emerald); margin-bottom: .7rem; }
.cap ul li { color: var(--muted); font-size: .88rem; padding: .18rem 0; }

/* ── contact ── */
#contact { text-align: center; }
#contact .container { max-width: 720px; }
#contact h2 { margin: 1rem 0 1rem; font-size: clamp(2rem, 4.5vw, 3.2rem); }
#contact .lead { color: var(--muted); font-size: 1.12rem; margin-bottom: 2.2rem; }
.contact-actions { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.contact-links { display: flex; gap: 2rem; justify-content: center; flex-wrap: wrap; margin-top: 2.5rem; font-family: var(--mono); font-size: .84rem; }
.contact-links a { color: var(--muted); display: inline-flex; align-items: center; gap: .45rem; }
.contact-links a:hover { color: var(--emerald); }

/* ── footer ── */
footer { border-top: 1px solid var(--border); padding: 2.2rem 0; }
.footer-inner { max-width: var(--max); margin: 0 auto; padding: 0 1.6rem; display: flex; justify-content: space-between; align-items: center; gap: 1rem; flex-wrap: wrap; font-family: var(--mono); font-size: .76rem; color: var(--dim); }
.footer-inner a { color: var(--muted); }

/* ── reveal anim ── */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ── responsive ── */
@media (max-width: 940px) {
  .hero-inner { grid-template-columns: 1fr; gap: 2.5rem; }
  .hero-card { max-width: 460px; }
  .thesis-body, .arch-wrap { grid-template-columns: 1fr; gap: 2rem; }
  .project-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .cap-grid { grid-template-columns: repeat(2, 1fr); }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat:nth-child(2) { border-right: 0; }
  .stat:nth-child(1), .stat:nth-child(2) { border-bottom: 1px solid var(--border); }
}
@media (max-width: 620px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0;
    background: rgba(8,11,16,.97); backdrop-filter: blur(16px); padding: 1.2rem 1.6rem; gap: 1.1rem;
    border-bottom: 1px solid var(--border);
  }
  .nav-toggle { display: block; }
  .metrics { grid-template-columns: 1fr 1fr; }
  .cap-grid { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr; }
  .stat { border-right: 0 !important; border-bottom: 1px solid var(--border); }
  .stat:last-child { border-bottom: 0; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}