/* Cellar — the server room in your cellphone.
   Theme: a warm bulb in a dark basement. Amber light, green LEDs,
   cool dark steel. No frameworks, no webfonts — system stacks only. */

:root {
  --bg: #07090d;
  --bg-2: #0b0e14;
  --panel: #0e1219;
  --line: #1b2230;
  --ink: #e9e5da;
  --muted: #96a0b0;
  --dim: #7b8698; /* ≥4.5:1 on all site backgrounds (WCAG AA) */
  --amber: #ffb454;
  --amber-soft: rgba(255, 180, 84, 0.14);
  --green: #46d47e;
  --green-soft: rgba(70, 212, 126, 0.12);
  --red: #ff6b6b;
  --mono: ui-monospace, "SF Mono", "Cascadia Code", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, Inter, sans-serif;
  --maxw: 1080px;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: var(--amber); color: #14100a; }

a { color: var(--amber); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

/* ---------- cellar atmosphere ---------- */

.grain::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 50;
  background:
    radial-gradient(ellipse 90% 60% at 50% -10%, rgba(255, 180, 84, 0.06), transparent 60%),
    radial-gradient(ellipse 120% 80% at 50% 110%, rgba(0, 0, 0, 0.55), transparent 60%);
}

/* ---------- nav ---------- */

.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  background: linear-gradient(rgba(7, 9, 13, 0.92), rgba(7, 9, 13, 0.75) 70%, transparent);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.nav .brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  color: var(--ink);
}
.nav .brand:hover { text-decoration: none; }
.nav .brand svg { display: block; }

.nav .links {
  display: flex;
  gap: 22px;
  align-items: center;
  font-size: 0.92rem;
}
.nav .links a { color: var(--muted); }
.nav .links a:hover { color: var(--ink); text-decoration: none; }
.nav .links a.cta {
  color: var(--amber);
  border: 1px solid rgba(255, 180, 84, 0.35);
  padding: 6px 14px;
  border-radius: 8px;
  transition: background 0.2s, color 0.2s;
}
.nav .links a.cta:hover { background: var(--amber); color: #14100a; }

/* ---------- hero ---------- */

.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  justify-content: center;
  /* stands alone if WebGL is unavailable: same mood, no canvas */
  background:
    radial-gradient(ellipse 70% 45% at 50% 30%, rgba(255, 180, 84, 0.08), transparent 65%),
    radial-gradient(ellipse 55% 35% at 50% 78%, rgba(70, 212, 126, 0.05), transparent 60%),
    var(--bg);
}

#scene {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  background: var(--bg); /* a dead canvas must never flash white */
}

.hero-copy {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 0 24px;
  max-width: 780px;
  pointer-events: none;
}
.hero-copy > * { pointer-events: auto; }

.hero-kicker {
  font-family: var(--mono);
  font-size: 0.85rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--green);
  margin-bottom: 18px;
}
.hero-kicker::before { content: "● "; animation: blink 2.4s infinite; }

@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0.25; } }

h1 {
  font-size: clamp(2.4rem, 6.5vw, 4.2rem);
  line-height: 1.05;
  font-weight: 750;
  letter-spacing: -0.02em;
  text-wrap: balance;
}
h1 em {
  font-style: normal;
  color: var(--amber);
  text-shadow: 0 0 34px rgba(255, 180, 84, 0.35);
}

.hero-sub {
  margin: 22px auto 0;
  max-width: 560px;
  color: var(--muted);
  font-size: 1.08rem;
  text-wrap: pretty;
}

.hero-ctas {
  margin-top: 34px;
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  font-family: var(--mono);
  font-size: 0.95rem;
  padding: 12px 22px;
  border-radius: 10px;
  border: 1px solid var(--line);
  color: var(--ink);
  background: rgba(14, 18, 25, 0.7);
  transition: transform 0.15s, background 0.2s, border-color 0.2s;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); border-color: var(--dim); }
.btn.primary {
  background: var(--amber);
  border-color: var(--amber);
  color: #14100a;
  font-weight: 600;
}
.btn.primary:hover { background: #ffc271; }

.scroll-hint {
  position: absolute;
  bottom: 26px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--dim);
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  animation: sink 2.6s ease-in-out infinite;
}
@keyframes sink { 0%, 100% { transform: translate(-50%, 0); } 50% { transform: translate(-50%, 7px); } }

/* ---------- sections ---------- */

section { position: relative; z-index: 2; }

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 96px 24px;
}

.kicker {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 12px;
}

h2 {
  font-size: clamp(1.7rem, 3.6vw, 2.5rem);
  letter-spacing: -0.015em;
  line-height: 1.15;
  margin-bottom: 14px;
  text-wrap: balance;
}

.lead {
  color: var(--muted);
  max-width: 640px;
  font-size: 1.05rem;
  margin-bottom: 44px;
  text-wrap: pretty;
}

/* cards */

.grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.card {
  background: linear-gradient(180deg, var(--panel), var(--bg-2));
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 26px 24px;
  transition: border-color 0.25s, transform 0.25s;
}
.card:hover { border-color: rgba(255, 180, 84, 0.35); transform: translateY(-2px); }

.card .icon {
  font-family: var(--mono);
  color: var(--green);
  font-size: 1.1rem;
  margin-bottom: 14px;
  display: inline-block;
  background: var(--green-soft);
  border: 1px solid rgba(70, 212, 126, 0.25);
  border-radius: 8px;
  padding: 6px 10px;
}
.card.amber .icon {
  color: var(--amber);
  background: var(--amber-soft);
  border-color: rgba(255, 180, 84, 0.3);
}

.card h3 { font-size: 1.08rem; margin-bottom: 8px; letter-spacing: -0.01em; }
.card p { color: var(--muted); font-size: 0.95rem; }
.card p code, .lead code, li code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 1px 6px;
  color: var(--ink);
}

/* architecture diagram */

.arch {
  font-family: var(--mono);
  font-size: 0.86rem;
  line-height: 1.7;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 28px;
  overflow-x: auto;
  color: var(--muted);
  white-space: pre;
}
.arch b { color: var(--amber); font-weight: 600; }
.arch i { color: var(--green); font-style: normal; }

/* reality section */

.reality { background: linear-gradient(180deg, transparent, rgba(255, 107, 107, 0.03), transparent); }
.reality .card { border-left: 3px solid rgba(255, 107, 107, 0.4); border-radius: 6px 14px 14px 6px; }
.reality .card h3 { color: var(--ink); }

/* terminal */

.term {
  background: #05070a;
  border: 1px solid var(--line);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.5);
}
.term-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--line);
  background: var(--bg-2);
}
.term-bar span { width: 11px; height: 11px; border-radius: 50%; background: var(--line); }
.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 em {
  font-style: normal;
  margin-left: auto;
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--dim);
}
.term pre {
  padding: 22px 24px;
  font-family: var(--mono);
  font-size: 0.9rem;
  line-height: 1.85;
  overflow-x: auto;
}
.term .p { color: var(--green); user-select: none; }
.term .c { color: var(--dim); }
.term .o { color: var(--muted); }

/* FAQ */

details {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel);
  margin-bottom: 12px;
  overflow: hidden;
}
summary {
  cursor: pointer;
  padding: 18px 22px;
  font-weight: 600;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}
summary::-webkit-details-marker { display: none; }
summary::after {
  content: "+";
  font-family: var(--mono);
  color: var(--amber);
  font-size: 1.2rem;
  transition: transform 0.2s;
}
details[open] summary::after { transform: rotate(45deg); }
details .a { padding: 0 22px 20px; color: var(--muted); font-size: 0.96rem; }
details .a a { color: var(--amber); }

/* footer */

footer {
  border-top: 1px solid var(--line);
  padding: 44px 24px 60px;
  position: relative;
  z-index: 2;
}
.foot {
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  justify-content: space-between;
  align-items: center;
  color: var(--dim);
  font-size: 0.88rem;
}
.foot .fbrand { font-family: var(--mono); color: var(--muted); display: flex; gap: 10px; align-items: center; }
.foot nav { display: flex; gap: 18px; }
.foot a { color: var(--muted); }

.badge {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  padding: 3px 10px;
  border-radius: 999px;
  border: 1px solid rgba(70, 212, 126, 0.35);
  color: var(--green);
  background: var(--green-soft);
  vertical-align: middle;
}
.badge.warn { border-color: rgba(255, 180, 84, 0.4); color: var(--amber); background: var(--amber-soft); }

/* scroll reveal — hidden state only when JS is present (the html.js
   class), so content never depends on JS to be visible */

.js .reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.7s ease, transform 0.7s ease; }
.js .reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  /* .js .reveal outspecifies a bare .reveal — media queries add no specificity */
  .js .reveal, .reveal { opacity: 1; transform: none; transition: none; }
  .scroll-hint, .hero-kicker::before { animation: none; }
}

@media (max-width: 640px) {
  .nav .links a:not(.cta) { display: none; }
  .wrap { padding: 72px 20px; }
}