/* FiberOS — marketing site. Hand-set, dark, terminal-grade. No frameworks. */

:root {
  --bg: #0a0d10;
  --panel: #0f141a;
  --panel-2: #131a21;
  --border: #1e2830;
  --fg: #dee6ec;
  --muted: #7d8b96;
  --accent: #3adb84;
  --accent-dim: rgba(58, 219, 132, 0.12);
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: "Space Grotesk", system-ui, -apple-system, sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; }

::selection { background: var(--accent); color: #06130c; }

/* ------------------------------------------------------------ topbar */
.topbar {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 2rem;
  padding: 0.9rem clamp(1.25rem, 4vw, 3rem);
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.wordmark {
  display: inline-flex; align-items: center; gap: 0.55rem;
  font-weight: 700; font-size: 1.05rem; letter-spacing: -0.01em;
  text-decoration: none;
}
.wordmark .mark {
  width: 13px; height: 13px; border-radius: 50%;
  border: 2.5px solid var(--accent);
  box-shadow: 0 0 10px rgba(58, 219, 132, 0.55);
}
.wordmark.small { font-size: 0.95rem; }
.topbar nav { display: flex; gap: 1.4rem; margin-left: auto; }
.topbar nav a {
  font-size: 0.9rem; color: var(--muted); text-decoration: none;
  transition: color 150ms;
}
.topbar nav a:hover { color: var(--fg); }

/* ------------------------------------------------------------ buttons */
.btn {
  display: inline-block; text-decoration: none;
  font-weight: 600; font-size: 0.92rem;
  padding: 0.6rem 1.15rem; border-radius: 8px;
  transition: opacity 150ms, background 150ms;
}
.btn-solid { background: var(--accent); color: #06130c; }
.btn-solid:hover { opacity: 0.88; }
.btn-ghost { border: 1px solid var(--border); color: var(--fg); }
.btn-ghost:hover { background: var(--panel-2); }
.btn-lg { font-size: 1.05rem; padding: 0.85rem 1.6rem; font-family: var(--mono); font-weight: 500; }

/* ------------------------------------------------------------ kicker */
.kicker {
  font-family: var(--mono);
  font-size: 0.72rem; font-weight: 500;
  text-transform: uppercase; letter-spacing: 0.22em;
  color: var(--accent);
  margin-bottom: 1rem;
}

/* ------------------------------------------------------------ hero */
.hero {
  max-width: 1100px; margin: 0 auto;
  padding: clamp(4rem, 9vh, 7rem) clamp(1.25rem, 4vw, 3rem) 0;
  text-align: center;
}
.hero h1 {
  font-size: clamp(2.4rem, 6vw, 4.2rem);
  line-height: 1.06; letter-spacing: -0.03em; font-weight: 700;
}
.hero h1 em {
  font-style: normal; color: var(--accent);
}
.hero .sub {
  max-width: 34em; margin: 1.4rem auto 0;
  color: var(--muted); font-size: 1.08rem;
}
.cta-row { display: flex; gap: 0.8rem; justify-content: center; margin-top: 2rem; }

/* ------------------------------------------------------------ frames */
.frame {
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  background: var(--panel);
}
.frame .chrome {
  display: flex; align-items: center; gap: 6px;
  padding: 9px 12px;
  border-bottom: 1px solid var(--border);
  background: var(--panel-2);
}
.frame .chrome i {
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--border); display: inline-block;
}
.frame .chrome span {
  margin: 0 auto;
  font-family: var(--mono); font-size: 0.7rem; color: var(--muted);
}
.hero-shot { margin: 3.2rem auto 0; max-width: 1050px; }

/* ------------------------------------------------------------ proof */
.proof {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin-top: 4.5rem;
  padding: 1.6rem clamp(1.25rem, 4vw, 3rem);
  background: var(--panel);
}
.proof-label {
  text-align: center;
  font-family: var(--mono); font-size: 0.68rem;
  text-transform: uppercase; letter-spacing: 0.22em;
  color: var(--muted); margin-bottom: 0.9rem;
}
.proof ul {
  list-style: none;
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 1rem 3.5rem;
  font-family: var(--mono); font-size: 0.88rem; color: var(--muted);
}
.proof b { color: var(--fg); font-weight: 500; margin-right: 0.45em; font-size: 1.05rem; }

/* ------------------------------------------------------------ features */
.features {
  max-width: 1180px; margin: 0 auto;
  padding: clamp(3rem, 8vh, 6rem) clamp(1.25rem, 4vw, 3rem);
  display: flex; flex-direction: column; gap: clamp(4rem, 9vh, 7rem);
}
.feature {
  display: grid; grid-template-columns: minmax(300px, 5fr) 7fr;
  gap: clamp(2rem, 4vw, 4rem); align-items: center;
}
.feature.flip { grid-template-columns: 7fr minmax(300px, 5fr); }
.feature.flip .feature-copy { order: 2; }
.feature h2 {
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  line-height: 1.2; letter-spacing: -0.02em; margin-bottom: 1rem;
}
.feature p { color: var(--muted); font-size: 0.98rem; }
.feature code {
  font-family: var(--mono); font-size: 0.85em;
  background: var(--accent-dim); color: var(--accent);
  padding: 0.1em 0.4em; border-radius: 5px;
}
.ticks { list-style: none; margin-top: 1.3rem; display: grid; gap: 0.55rem; }
.ticks li {
  position: relative; padding-left: 1.5rem;
  font-size: 0.92rem; color: var(--fg);
}
.ticks li::before {
  content: "▸"; position: absolute; left: 0;
  color: var(--accent); font-family: var(--mono);
}
.ticks em { font-style: normal; color: var(--accent); }

/* ------------------------------------------------------------ capability grid */
.grid-section {
  border-top: 1px solid var(--border);
  padding: clamp(3rem, 8vh, 5.5rem) clamp(1.25rem, 4vw, 3rem);
  max-width: 1180px; margin: 0 auto;
}
.cap-grid {
  display: grid; gap: 1px;
  grid-template-columns: repeat(3, 1fr); /* 6 cards -> balanced 3x2 */
  background: var(--border);
  border: 1px solid var(--border); border-radius: 12px;
  overflow: hidden;
}
@media (max-width: 900px) { .cap-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .cap-grid { grid-template-columns: 1fr; } }
.cap { background: var(--panel); padding: 1.5rem 1.6rem; }
.cap h3 {
  font-size: 0.95rem; font-weight: 600; margin-bottom: 0.45rem;
  letter-spacing: -0.01em;
}
.cap p { font-size: 0.88rem; color: var(--muted); }

/* ------------------------------------------------------------ story */
.story {
  border-top: 1px solid var(--border);
  background: var(--panel);
  padding: clamp(3.5rem, 9vh, 6rem) clamp(1.25rem, 4vw, 3rem);
}
.story > * { max-width: 1000px; margin-left: auto; margin-right: auto; }
.story h2 {
  font-size: clamp(1.7rem, 3.2vw, 2.4rem);
  letter-spacing: -0.02em; line-height: 1.15;
  margin-bottom: 1.6rem; max-width: 18em;
}
.story-cols {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 2.5rem; color: var(--muted); font-size: 0.98rem;
}
.story-cols a { color: var(--fg); }
.story-cols em { font-style: normal; color: var(--accent); }

/* ------------------------------------------------------------ stack */
.stack {
  max-width: 1000px; margin: 0 auto;
  padding: clamp(3rem, 8vh, 5.5rem) clamp(1.25rem, 4vw, 3rem);
  text-align: center;
}
.stack-line {
  display: flex; flex-wrap: wrap; justify-content: center; align-items: center;
  gap: 0.7rem 0.9rem;
  font-family: var(--mono); font-size: 0.88rem;
}
.stack-line span:not(.arrow) {
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--panel); padding: 0.5rem 0.9rem;
}
.stack-line .arrow { color: var(--accent); }
.stack-facts {
  list-style: none;
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 0.5rem 2.2rem;
  margin-top: 1.8rem;
  font-size: 0.85rem; color: var(--muted);
}
.stack-facts li::before { content: "— "; color: var(--accent); }

/* ------------------------------------------------------------ closing */
.closing {
  border-top: 1px solid var(--border);
  text-align: center;
  padding: clamp(4rem, 10vh, 7rem) clamp(1.25rem, 4vw, 3rem);
}
.closing h2 { font-size: clamp(1.8rem, 3.4vw, 2.6rem); letter-spacing: -0.02em; }
.closing p { color: var(--muted); margin: 0.7rem 0 1.8rem; }

/* ------------------------------------------------------------ footer */
footer {
  border-top: 1px solid var(--border);
  display: flex; flex-wrap: wrap; align-items: center; gap: 1rem;
  justify-content: space-between;
  padding: 1.4rem clamp(1.25rem, 4vw, 3rem);
}
.foot-note { font-size: 0.78rem; color: var(--muted); font-family: var(--mono); }

/* ------------------------------------------------------------ mobile */
@media (max-width: 860px) {
  .topbar nav { display: none; }
  .feature, .feature.flip { grid-template-columns: 1fr; }
  .feature.flip .feature-copy { order: 0; }
  .story-cols { grid-template-columns: 1fr; }
}