:root {
  --surface-sky: #eef7f9;
  --ink-deep: #0e2a36;
  --foam: #f4fbfc;
  --abyss-text: #c8dde5;
  --abyss-muted: #7e9aa6;
  --accent-light: #0b7285;
  --accent-glow: #5fd4e8;
  --deep-text: #e7f2f5;
  --deep-soft: #c3d9e0;
  --deep-rule: rgba(231, 242, 245, 0.25);
  --serif: "Source Serif 4", Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

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

html {
  scroll-behavior: smooth;
  /* Anything past the gradient stays abyss-dark (short pages, overscroll) */
  background: #060f17;
}

body {
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.7;
  color: var(--ink-deep);
  min-height: 100vh;
  background-repeat: no-repeat;
}

/* Homepage: one continuous descent, proportional to the full page */
body.dive-home {
  background: linear-gradient(
    to bottom,
    #eef7f9 0%,
    #d9edf1 9%,
    #b6dde6 18%,
    #8cc3d2 28%,
    #5d9fb4 38%,
    #3d7d95 48%,
    #2a5f77 58%,
    #1c465c 68%,
    #122f42 78%,
    #0b1f2e 88%,
    #060f17 100%
  );
}

/* Inner pages: slow, gentle descent — dark ink works throughout.
   Pages may not reach the deep end; that's intentional. */
body.dive-inner {
  background: linear-gradient(
    to bottom,
    #eef7f9  0%,
    #e2f1f5 15%,
    #cce5ec 30%,
    #b3d6df 50%,
    #97c6d1 70%,
    #7db3c3 90%,
    #6dafc0 100%
  );
}

/* Inner pages stay in the light-to-medium range, so dark ink is used
   throughout — no need to switch to the deep-sea light palette. */
body.dive-inner section,
body.dive-inner .abyss              { color: var(--ink-deep); }

body.dive-inner .zone-intro         { color: #1d4254; }
body.dive-inner .arrow-link         { color: var(--accent-light); }
body.dive-inner .abyss .arrow-link  { color: var(--accent-light); }
body.dive-inner .abyss .btn         { background: var(--ink-deep); color: var(--foam); }
body.dive-inner .abyss .btn:hover   { background: #1d4356; }

body.dive-inner .prose              { color: #2c4d5e; }
body.dive-inner .prose h2           { color: var(--ink-deep); }
body.dive-inner .prose a            { color: var(--accent-light); }
body.dive-inner .prose strong       { color: var(--ink-deep); }
body.dive-inner .prose li::marker   { color: var(--accent-light); }

body.dive-inner .status-list,
body.dive-inner .status-item        { border-color: rgba(14, 42, 54, 0.15); }
body.dive-inner .status-item h3     { color: var(--ink-deep); }
body.dive-inner .status-item p,
body.dive-inner .status-item ul     { color: #2c4d5e; }
body.dive-inner .status-item li::marker { color: var(--accent-light); }
body.dive-inner .status-label.ok    { color: #1a6b35; }
body.dive-inner .status-label.poc   { color: #7a5200; }
body.dive-inner .status-label.early { color: #1a4f7a; }

body.dive-inner .faq-list,
body.dive-inner .faq-list details   { border-color: rgba(14, 42, 54, 0.15); }
body.dive-inner .faq-list summary   { color: var(--ink-deep); }
body.dive-inner .faq-list summary::after { color: var(--accent-light); }
body.dive-inner .faq-list .answer   { color: #2c4d5e; }
body.dive-inner .faq-list .answer a { color: var(--accent-light); }
body.dive-inner .faq-list .answer code { background: rgba(14, 42, 54, 0.06); }

body.dive-inner .contact-list,
body.dive-inner .contact-item       { border-color: rgba(14, 42, 54, 0.15); }
body.dive-inner .contact-item h3    { color: var(--ink-deep); }
body.dive-inner .contact-item p     { color: #2c4d5e; }
body.dive-inner .contact-item a     { color: var(--accent-light); }

body.dive-inner .site-footer        { color: #335263; border-color: rgba(14, 42, 54, 0.15); }
body.dive-inner .site-footer a      { color: var(--ink-deep); }
body.dive-inner .seafloor           { color: #2c4d5e; }
body.dive-inner .depth              { color: var(--ink-deep); }

h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.25; }


.container { max-width: 920px; margin: 0 auto; padding: 0 24px; }

a { color: inherit; }

/* ------- Depth marker labels ------- */
.depth {
  display: flex; align-items: center; gap: 14px;
  font-family: var(--mono); font-size: 0.78rem;
  letter-spacing: 0.14em; text-transform: uppercase;
  margin-bottom: 34px;
}
.depth::before {
  content: ""; width: 46px; height: 1px; background: currentColor; opacity: 0.6;
}
.depth::after {
  content: ""; flex: 1; height: 1px; background: currentColor; opacity: 0.15;
}

/* ------- Header ------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(238, 247, 249, 0.92);
  border-bottom: 1px solid rgba(14, 42, 54, 0.12);
}
.site-header .container {
  display: flex; align-items: center; justify-content: space-between;
  height: 62px; gap: 24px;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--serif); font-weight: 700; font-size: 1.2rem;
  color: var(--ink-deep); text-decoration: none;
}
.brand img { height: 30px; }
.site-nav { display: flex; gap: 24px; flex-wrap: wrap; }
.site-nav a {
  color: #335263; font-size: 0.92rem; text-decoration: none;
}
.site-nav a:hover { color: var(--accent-light); text-decoration: underline; text-underline-offset: 5px; }
.site-nav a[aria-current="page"] { color: var(--ink-deep); font-weight: 600; }

/* Hamburger — CSS-only via hidden checkbox */
.nav-checkbox { display: none; }

.nav-toggle {
  display: none;
  flex-direction: column; gap: 5px;
  cursor: pointer; padding: 6px; margin: -6px;
  color: var(--ink-deep);
}
.nav-toggle span {
  display: block; width: 22px; height: 2px;
  background: currentColor; border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}
.nav-checkbox:checked ~ .nav-toggle span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-checkbox:checked ~ .nav-toggle span:nth-child(2) { opacity: 0; }
.nav-checkbox:checked ~ .nav-toggle span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 700px) {
  .site-header .container { position: relative; }
  .nav-toggle { display: flex; }

  .site-nav {
    display: none;
    position: absolute; top: 62px; left: 0; right: 0;
    flex-direction: column; gap: 0;
    background: rgba(238, 247, 249, 0.98);
    border-bottom: 1px solid rgba(14, 42, 54, 0.12);
  }
  .nav-checkbox:checked ~ .site-nav { display: flex; }
  .site-nav a {
    padding: 14px 24px;
    border-top: 1px solid rgba(14, 42, 54, 0.07);
    font-size: 1rem;
  }
}

/* ------- Surface (homepage hero) ------- */
.surface { padding: 90px 0 110px; }
.surface h1 {
  font-size: clamp(2.3rem, 5.5vw, 3.6rem);
  max-width: 17ch; margin-bottom: 24px;
}
.surface .lede {
  font-size: 1.18rem; color: #2c4d5e; max-width: 56ch; margin-bottom: 38px;
}
.btn-row { display: flex; align-items: center; gap: 26px; flex-wrap: wrap; }
.btn {
  display: inline-block; background: var(--ink-deep); color: var(--foam);
  font-weight: 600; font-size: 0.96rem; padding: 13px 28px;
  border-radius: 4px; text-decoration: none;
}
.btn:hover { background: #1d4356; }
.arrow-link { font-weight: 600; font-size: 0.96rem; color: var(--accent-light); }
.arrow-link::after { content: " ↓"; }
.arrow-link.ext::after { content: " →"; }

.surface .dive-note {
  margin-top: 70px; font-family: var(--mono); font-size: 0.8rem;
  letter-spacing: 0.12em; text-transform: uppercase; color: #46707f;
}

/* ------- Inner page hero (still at the surface) ------- */
.page-hero { padding: 56px 0 80px; color: var(--ink-deep); }
.page-hero h1 {
  font-size: clamp(2rem, 4.5vw, 2.8rem);
  max-width: 22ch; margin-bottom: 16px;
}
.page-hero .lede { font-size: 1.12rem; color: #1d4254; max-width: 58ch; }
.page-hero .lede a { color: var(--accent-light); }

/* ------- Sections (zones) ------- */
section { padding: 96px 0; }
body.dive-inner section { padding: 70px 0; }

section h2 { font-size: clamp(1.6rem, 3.2vw, 2.2rem); margin-bottom: 18px; }
section .zone-intro { max-width: 62ch; margin-bottom: 18px; }

/* Zone 1: periscope depth — still dark text on mid-light water */
.zone-periscope { color: #11313f; }
.zone-periscope .zone-intro { color: #1d4254; }

.feature-cols { display: grid; grid-template-columns: repeat(3, 1fr); gap: 36px; margin-top: 46px; }
@media (max-width: 760px) { .feature-cols { grid-template-columns: 1fr; gap: 28px; } }
.feature-cols > div {
  border-top: 2px solid rgba(17, 49, 63, 0.55);
  padding-top: 16px;
}
.feature-cols h3 { font-size: 1.1rem; margin-bottom: 8px; }
.feature-cols p { font-size: 0.94rem; }
.zone-periscope .feature-cols p { color: #1d4254; }

/* Zone 2: twilight — light text begins */
.zone-twilight { color: var(--deep-text); }
.zone-twilight .zone-intro { color: var(--deep-soft); }
.zone-twilight .arrow-link { color: var(--accent-glow); }

/* Generic deep zone for inner-page content (light text on dark water) */
.zone-deep { color: var(--deep-text); }
.zone-deep .zone-intro { color: var(--deep-soft); }
.zone-deep .arrow-link { color: var(--accent-glow); }

/* Shallow zone — dark ink for sections near the surface (light/medium background) */
.zone-light { color: var(--ink-deep); }
.zone-light .zone-intro { color: #1d4254; }
.zone-light .arrow-link { color: var(--accent-light); }
.zone-light .prose { color: #2c4d5e; }
.zone-light .prose h2 { color: var(--ink-deep); }
.zone-light .prose a { color: var(--accent-light); }
.zone-light .prose strong { color: var(--ink-deep); }
.zone-light .prose li::marker { color: var(--accent-light); }
.zone-light .status-list,
.zone-light .status-item { border-color: rgba(14, 42, 54, 0.15); }
.zone-light .status-item h3 { color: var(--ink-deep); }
.zone-light .status-item p,
.zone-light .status-item ul { color: #2c4d5e; }
.zone-light .status-item li::marker { color: var(--accent-light); }
.zone-light .faq-list,
.zone-light .faq-list details { border-color: rgba(14, 42, 54, 0.15); }
.zone-light .faq-list summary { color: var(--ink-deep); }
.zone-light .faq-list summary::after { color: var(--accent-light); }
.zone-light .faq-list .answer { color: #2c4d5e; }
.zone-light .faq-list .answer a { color: var(--accent-light); }
.zone-light .faq-list .answer code { background: rgba(14, 42, 54, 0.06); }
.zone-light .contact-list,
.zone-light .contact-item { border-color: rgba(14, 42, 54, 0.15); }
.zone-light .contact-item h3 { color: var(--ink-deep); }
.zone-light .contact-item p { color: #2c4d5e; }
.zone-light .contact-item a { color: var(--accent-light); }
.zone-light .status-label.ok { color: #1a6b35; }
.zone-light .status-label.poc { color: #7a5200; }
.zone-light .status-label.early { color: #1a4f7a; }

/* ------- Status list ------- */
.status-list { margin-top: 38px; border-top: 1px solid var(--deep-rule); }
.status-item {
  display: grid; grid-template-columns: 210px 1fr; gap: 12px 40px;
  padding: 24px 0; border-bottom: 1px solid var(--deep-rule);
}
@media (max-width: 760px) { .status-item { grid-template-columns: 1fr; } }
.status-item h3 { font-size: 1.08rem; margin-bottom: 4px; }
.status-label {
  display: block; font-family: var(--mono); font-size: 0.72rem;
  font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase;
}
.status-label.ok { color: #9fe6b0; }
.status-label.poc { color: #f5d58a; }
.status-label.early { color: #9cc8f0; }
.status-item p { color: var(--deep-soft); font-size: 0.95rem; }
.status-item ul {
  margin: 10px 0 0 20px; color: var(--deep-soft); font-size: 0.95rem;
}
.status-item li { margin-bottom: 6px; }
.status-item li::marker { color: var(--abyss-muted); }

/* Zone 3: midnight — pull-quote */
.zone-midnight { color: #d7e6ec; }
.zone-midnight .zone-intro { color: #aac3cd; }
.zone-midnight blockquote {
  font-family: var(--serif); font-size: clamp(1.25rem, 2.6vw, 1.7rem);
  line-height: 1.5; max-width: 26ch; margin: 30px 0;
}
.zone-midnight blockquote em { color: var(--accent-glow); font-style: normal; }

/* ------- Prose (about, contribute) ------- */
.prose { max-width: 68ch; color: var(--deep-soft); }
.prose h2 { color: var(--deep-text); font-size: 1.5rem; margin: 48px 0 14px; }
.prose h2:first-child { margin-top: 0; }
.prose p { margin-bottom: 16px; }
.prose ul { margin: 0 0 16px 22px; }
.prose li { margin-bottom: 10px; }
.prose li::marker { color: var(--abyss-muted); }
.prose a { color: var(--accent-glow); }
.prose strong { color: var(--deep-text); }

/* ------- FAQ list ------- */
.faq-list { border-top: 1px solid var(--deep-rule); }
.faq-list details { border-bottom: 1px solid var(--deep-rule); }
.faq-list summary {
  cursor: pointer; list-style: none; position: relative;
  padding: 22px 44px 22px 0;
  font-family: var(--serif); font-weight: 600; font-size: 1.12rem;
  color: var(--deep-text);
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: "+"; position: absolute; right: 6px; top: 50%;
  transform: translateY(-50%);
  font-family: var(--mono); font-size: 1.2rem; font-weight: 400;
  color: var(--accent-glow);
}
.faq-list details[open] summary::after { content: "−"; }
.faq-list .answer { padding: 0 0 24px; max-width: 66ch; color: var(--deep-soft); }
.faq-list .answer a { color: var(--accent-glow); }
.faq-list .answer code {
  font-family: var(--mono); font-size: 0.88em;
  background: rgba(255, 255, 255, 0.08);
  padding: 1px 6px; border-radius: 3px;
}

/* ------- Contact list ------- */
.contact-list { margin-top: 10px; border-top: 1px solid var(--deep-rule); }
.contact-item {
  display: grid; grid-template-columns: 180px 1fr; gap: 12px 40px;
  padding: 26px 0; border-bottom: 1px solid var(--deep-rule);
}
@media (max-width: 760px) { .contact-item { grid-template-columns: 1fr; } }
.contact-item h3 { font-size: 1.1rem; }
.contact-item p { color: var(--deep-soft); font-size: 0.95rem; margin-bottom: 6px; }
.contact-item a { color: var(--accent-glow); font-size: 0.95rem; }

/* ------- Abyss: closing + footer ------- */
.abyss { color: var(--abyss-text); padding: 110px 0 0; position: relative; }
body.dive-inner .abyss { padding: 80px 0 60px; }
.abyss h2 { font-size: clamp(1.6rem, 3.2vw, 2.2rem); margin-bottom: 16px; }
.abyss .zone-intro { color: var(--abyss-muted); max-width: 56ch; margin-bottom: 32px; }
.abyss .btn { background: var(--accent-glow); color: #06222c; }
.abyss .btn:hover { background: #83e0ef; }
.abyss .arrow-link { color: var(--accent-glow); }

.abyss .sub-art { margin-bottom: 40px; }
.abyss .sub-art img {
  height: 72px;
  transform: rotate(12deg);
  opacity: 0.95;
}

.site-footer {
  margin-top: 90px;
  border-top: 1px solid rgba(200, 221, 229, 0.18);
  padding-top: 30px;
  display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap;
  font-size: 0.86rem; color: var(--abyss-muted);
}
body.dive-inner .site-footer { margin-top: 70px; }
.site-footer a { color: var(--abyss-text); }
.site-footer nav { display: flex; gap: 20px; flex-wrap: wrap; }

.seafloor {
  margin-top: 50px;
  font-family: var(--mono); font-size: 0.74rem;
  letter-spacing: 0.16em; text-transform: uppercase; color: #41606d;
  text-align: center;
}

/* ------- Mobile ------- */
@media (max-width: 700px) {
  .surface { padding: 56px 0 70px; }
  .surface .dive-note { margin-top: 44px; }
  section { padding: 64px 0; }
  body.dive-inner section { padding: 48px 0; }
  .page-hero { padding: 40px 0 56px; }
  .abyss { padding-top: 72px; }
  body.dive-inner .abyss { padding-top: 56px; }
  .site-footer { flex-direction: column; gap: 18px; }
  .abyss .zone-intro { max-width: 100%; }
}

/* ------- Easter egg: shipwreck ------- */
.shipwreck {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  line-height: 0;
  z-index: 0;
  pointer-events: none;
}
.shipwreck-img {
  display: block;
  width: 100%;
  mix-blend-mode: multiply;
  opacity: 0.3;
}
.abyss .container {
  position: relative;
  z-index: 1;
  padding-bottom: 60px;
}