/* ============================================================================
 * Selat Labs — styles.css
 * Tema gelap infra (Linear/Vercel-arah), satu halaman, tiada dependency luar.
 * Semua token warna dalam :root. Setiap pasangan warna yang digunakan diuji
 * kontras >= 4.5:1 dalam tools/check_contrast.py.
 * ==========================================================================*/

:root {
  /* permukaan */
  --bg:            #08090a;
  --bg-alt:        #0b0d11;
  --surface:       #101317;
  --surface-2:     #14181e;
  --border:        #1e232a;
  --border-strong: #2b323c;

  /* teks */
  --text:      #e8eaed;
  --text-dim:  #a2abb8;
  --text-mute: #7b8695;

  /* aksen */
  --accent:      #6e7bff;
  --accent-soft: rgba(110, 123, 255, .12);
  --accent-line: rgba(110, 123, 255, .28);
  --accent-2:    #35e0c8;
  --accent-ink:  #08090a;

  /* bentuk */
  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 20px;
  --wrap: 1180px;
  --pad: 22px;

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

*, *::before, *::after { box-sizing: border-box; }

/* Atribut `hidden` mesti menang atas display:grid/flex daripada kelas author —
   tanpa ini, baris facts / seksyen AI yang sepatutnya tersembunyi tetap kelihatan. */
[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img, svg { max-width: 100%; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { margin: 0; line-height: 1.14; letter-spacing: -0.02em; font-weight: 600; }
p { margin: 0; }

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--pad);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: var(--accent-ink);
  padding: 10px 16px;
  border-radius: 0 0 var(--r-sm) 0;
  z-index: 60;
  font-weight: 600;
}
.skip-link:focus { left: 0; }

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ============================== BUTTONS ================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 10px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background-color .18s ease, border-color .18s ease, color .18s ease, transform .18s ease;
  white-space: nowrap;
}
.btn-sm { padding: 9px 15px; font-size: 14px; }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover { background: #8691ff; }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--border-strong); }
.btn-ghost:hover { border-color: var(--accent-line); background: var(--accent-soft); }

/* ============================== HEADER =================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(8, 9, 10, .82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 66px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; min-width: 0; }
.brand-mark { width: 30px; height: 30px; color: var(--accent); flex: none; }
.brand-name {
  font-weight: 650;
  letter-spacing: -0.01em;
  font-size: 17px;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  flex: none;
}
.nav-toggle-bars { display: block; width: 18px; }
.nav-toggle-bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
}
.nav-toggle-bars span + span { margin-top: 4px; }

.primary-nav {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
  padding: 14px var(--pad) 22px;
}
.primary-nav.is-open { display: block; }
.primary-nav ul { display: flex; flex-direction: column; gap: 2px; margin-bottom: 14px; }
/* Skop kepada `ul a` — bukan `.primary-nav a` — supaya CTA butang utama (.nav-cta)
   tidak diwarisi color --text-dim di atas latar aksen (itu 1.52:1, gagal WCAG). */
.primary-nav ul a {
  display: block;
  padding: 11px 4px;
  color: var(--text-dim);
  font-size: 15px;
  font-weight: 500;
  border-bottom: 1px solid var(--border);
}
.primary-nav li:last-child a { border-bottom: 0; }
.primary-nav ul a:hover { color: var(--text); }
.nav-cta { width: 100%; color: var(--accent-ink); }

@media (min-width: 900px) {
  .nav-toggle { display: none; }
  .primary-nav {
    display: flex;
    position: static;
    align-items: center;
    gap: 26px;
    background: none;
    border: 0;
    padding: 0;
    flex: 1;
    justify-content: flex-end;
  }
  .primary-nav ul { flex-direction: row; gap: 24px; margin: 0; }
  .primary-nav ul a {
    padding: 4px 0;
    border-bottom: 0;
    font-size: 14.5px;
    color: var(--text-dim);
  }
  .primary-nav ul a:hover { color: var(--accent); }
  .nav-cta { width: auto; }
}

/* =============================== HERO ==================================== */
.hero { position: relative; overflow: hidden; padding: 62px 0 68px; }
.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(255,255,255,.035) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,.035) 1px, transparent 1px);
  background-size: 62px 62px;
  mask-image: radial-gradient(ellipse 90% 70% at 50% 0%, #000 20%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 90% 70% at 50% 0%, #000 20%, transparent 78%);
  pointer-events: none;
}
.hero-inner { position: relative; display: grid; gap: 48px; }

.eyebrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .01em;
  color: var(--text-mute);
  margin-bottom: 20px;
}
.eyebrow .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent-2);
  box-shadow: 0 0 0 3px rgba(53, 224, 200, .16);
  flex: none;
}
.eyebrow .sep { color: var(--border-strong); }

h1 { font-size: clamp(2.1rem, 6.1vw, 3.6rem); letter-spacing: -0.035em; }
.lede {
  margin-top: 22px;
  font-size: clamp(1rem, 2.1vw, 1.13rem);
  color: var(--text-dim);
  max-width: 56ch;
}
.lede em { color: var(--text); font-style: normal; font-weight: 600; }

.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }

.stat-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 22px;
  margin-top: 46px;
  padding-top: 30px;
  border-top: 1px solid var(--border);
}
.stat-value {
  display: block;
  font-size: 15px;
  font-weight: 650;
  color: var(--text);
  letter-spacing: -0.01em;
}
.stat-label {
  display: block;
  margin-top: 3px;
  font-size: 12.5px;
  line-height: 1.45;
  color: var(--text-mute);
}
@media (min-width: 900px) {
  .stat-row { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

/* hero visual */
.viz-card {
  background: linear-gradient(180deg, var(--surface-2), var(--surface));
  border: 1px solid var(--border-strong);
  border-radius: var(--r-lg);
  padding: 18px;
  box-shadow: 0 24px 60px -30px rgba(0, 0, 0, .9);
}
.viz-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}
.viz-title { font-size: 13px; font-weight: 600; color: var(--text-dim); }
.viz-badge {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--accent-2);
  background: rgba(53, 224, 200, .1);
  border: 1px solid rgba(53, 224, 200, .28);
  padding: 3px 9px;
  border-radius: 999px;
}
.viz-svg { display: block; width: 100%; height: auto; }

.viz-node { fill: rgba(255,255,255,.025); stroke: var(--border-strong); stroke-width: 1.2; }
.viz-kicker {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: .14em;
  fill: var(--text-mute);
}
.viz-kicker-center { text-anchor: middle; }
.viz-label { font-size: 15px; font-weight: 600; fill: var(--text); }
.viz-sub { font-size: 11px; fill: var(--text-mute); }
.viz-rail { opacity: .55; }
.viz-dash { animation: dash 2.4s linear infinite; }
@keyframes dash { to { stroke-dashoffset: -32; } }
.viz-hub-outer { fill: none; stroke: var(--accent-line); stroke-width: 1; }
.viz-hub { fill: rgba(110, 123, 255, .14); stroke: var(--accent); stroke-width: 1.4; }
.viz-hub-label {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: .1em;
  fill: var(--text);
  text-anchor: middle;
}
.viz-pill { fill: rgba(255,255,255,.03); stroke: var(--border-strong); stroke-width: 1; }
.viz-pill-accent { fill: rgba(110, 123, 255, .14); stroke: var(--accent-line); }
.viz-pill-text {
  font-family: var(--mono);
  font-size: 10px;
  fill: var(--text-dim);
  text-anchor: middle;
}
.viz-foot {
  margin-top: 12px;
  font-size: 11.5px;
  color: var(--text-mute);
  text-align: center;
}
@media (min-width: 980px) {
  .hero { padding: 78px 0 92px; }
  .hero-inner { grid-template-columns: minmax(0, 1.02fr) minmax(0, .98fr); gap: 56px; align-items: center; }
}

/* ============================= SECTIONS ================================== */
.section { padding: 76px 0; }
.section-alt { background: var(--bg-alt); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-head { max-width: 62ch; margin-bottom: 40px; }
.section-kicker {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
}
.section h2 { font-size: clamp(1.6rem, 4vw, 2.3rem); }
.section-lede { margin-top: 16px; color: var(--text-dim); font-size: 1rem; }

/* =============================== CARDS =================================== */
.card-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}
.card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 24px 22px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: border-color .2s ease, background-color .2s ease;
}
.card:hover { border-color: var(--border-strong); background: var(--surface-2); }
.card h3 { font-size: 1.06rem; }
.card p { color: var(--text-dim); font-size: 14.5px; }
.card-num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--accent);
  opacity: .85;
}
.card-points { display: flex; flex-wrap: wrap; gap: 8px; margin-top: auto; padding-top: 6px; }
.card-points li {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-mute);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 4px 10px;
  white-space: nowrap;
}
.card-points-inline { margin-top: 0; }
.card-quiet { background: transparent; }
.card-wide { border-color: var(--accent-line); background: linear-gradient(160deg, var(--accent-soft), var(--surface) 62%); }

@media (min-width: 601px) {
  .card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 901px) {
  .card-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .card-wide { grid-column: span 2; }
  .card-grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .card-grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

/* =============================== STEPS =================================== */
.step-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  overflow: hidden;
}
.step { background: var(--bg-alt); padding: 24px 22px; }
.step-num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--accent);
}
.step h3 { margin-top: 10px; font-size: 1rem; }
.step p { margin-top: 8px; color: var(--text-dim); font-size: 14px; }
@media (min-width: 601px) { .step-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (min-width: 1000px) { .step-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); } }

/* ============================ CODE BLOCK ================================= */
.code-block {
  margin-top: 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  overflow: hidden;
}
.code-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 11px 16px;
  border-bottom: 1px solid var(--border);
  background: rgba(255,255,255,.015);
}
.code-lang { font-family: var(--mono); font-size: 11.5px; color: var(--text-mute); letter-spacing: .06em; }
.code-copy {
  font-family: inherit;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-dim);
  background: transparent;
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  padding: 5px 13px;
  cursor: pointer;
}
.code-copy:hover { color: var(--text); border-color: var(--accent-line); }
.code-block pre {
  margin: 0;
  padding: 18px 16px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 12.6px;
  line-height: 1.72;
  color: #cfd6e2;
  -webkit-overflow-scrolling: touch;
}

/* ============================== SPLIT ==================================== */
.split { display: grid; gap: 40px; }
.split-copy h2 { font-size: clamp(1.6rem, 4vw, 2.3rem); }
.split-copy p { margin-top: 16px; color: var(--text-dim); }
@media (min-width: 940px) {
  .section { padding: 96px 0; }
  .split { grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr); gap: 64px; align-items: start; }
}
.check-list { margin-top: 26px; display: grid; gap: 14px; }
.check-list li {
  position: relative;
  padding-left: 26px;
  color: var(--text-dim);
  font-size: 14.5px;
}
.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 12px;
  height: 12px;
  border-radius: 3px;
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
}
.check-list strong { color: var(--text); font-weight: 600; }

/* trail */
.trail { display: grid; gap: 0; }
.trail-item {
  position: relative;
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr);
  gap: 14px;
  padding-bottom: 26px;
}
.trail-item:last-child { padding-bottom: 0; }
.trail-item:not(:last-child)::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 22px;
  bottom: 0;
  width: 1px;
  background: var(--border-strong);
}
.trail-dot {
  width: 12px;
  height: 12px;
  margin-top: 5px;
  border-radius: 50%;
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  justify-self: center;
  z-index: 1;
}
.trail-dot-accent { background: var(--accent); border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
.trail-dot-quiet { background: var(--accent-2); border-color: var(--accent-2); }
.trail-title { font-size: 15px; font-weight: 600; }
.trail-meta { margin-top: 3px; font-family: var(--mono); font-size: 11.5px; color: var(--text-mute); }
.split-visual {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 26px 24px;
}

/* =============================== FACTS =================================== */
.facts { margin-top: 34px; }
.facts-rail {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.facts-rail span {
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--text-mute);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 13px;
}

/* =============================== CTA ==================================== */
.section-cta { background: var(--bg-alt); border-top: 1px solid var(--border); }
.cta-inner { display: grid; gap: 38px; }
.cta-copy h2 { font-size: clamp(1.7rem, 4.4vw, 2.4rem); }
.cta-copy p { margin-top: 16px; color: var(--text-dim); max-width: 52ch; }
.facts-list { display: grid; gap: 0; border-top: 1px solid var(--border); }
.facts-row {
  display: grid;
  grid-template-columns: minmax(0, 118px) minmax(0, 1fr);
  gap: 14px;
  padding: 13px 0;
  border-bottom: 1px solid var(--border);
}
.facts-row dt { font-size: 13px; color: var(--text-mute); }
.facts-row dd { margin: 0; font-size: 14px; color: var(--text); overflow-wrap: anywhere; }
.facts-row dd a { color: var(--accent); }
.facts-row dd a:hover { text-decoration: underline; }
@media (min-width: 940px) {
  .cta-inner { grid-template-columns: minmax(0, 1fr) minmax(0, .85fr); gap: 72px; align-items: start; }
}

/* ============================== FOOTER ================================== */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 44px 0 34px;
  background: var(--bg);
}
.footer-inner { display: grid; gap: 22px; }
.footer-brand .brand-name { display: block; font-size: 16px; }
.footer-brand p { margin-top: 6px; font-size: 13.5px; color: var(--text-mute); }
.footer-nav ul { display: flex; flex-wrap: wrap; gap: 8px 22px; }
.footer-nav a { font-size: 13.5px; color: var(--text-dim); }
.footer-nav a:hover { color: var(--accent); }
.footer-legal { font-size: 12.5px; color: var(--text-mute); }
@media (min-width: 800px) {
  .footer-inner { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); align-items: start; }
  .footer-legal { grid-column: 1 / -1; padding-top: 18px; border-top: 1px solid var(--border); }
}

/* ============================== MOTION ================================== */
.reveal { opacity: 0; transform: translateY(14px); }
.reveal.is-visible { opacity: 1; transform: none; transition: opacity .55s ease, transform .55s ease; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .viz-dash { animation: none; }
  .reveal, .reveal.is-visible { opacity: 1; transform: none; transition: none; }
  .btn, .card { transition: none; }
}