/* soning.stream — reasoning as geological excavation */

:root {
  --burnt: #c4613a;
  --canyon-deep: #8a3a1e;
  --sand: #f0e8de;
  --clay: #e8d4c4;
  --ochre: #d4a060;
  --slate: #6a6460;
  --basalt: #2a2420;
  --strata-1: #c4613a;
  --strata-2: #d4a060;
  --strata-3: #8a3a1e;
  --strata-4: #6a6460;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--sand);
  color: var(--basalt);
  font-family: 'Work Sans', sans-serif;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.55;
  overflow-x: hidden;
}

/* grain layer */
.grain-layer {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 100;
  opacity: 0.3;
  mix-blend-mode: multiply;
  animation: grainShift 8s steps(8) infinite;
}
@keyframes grainShift {
  0% { transform: translate(0, 0); }
  20% { transform: translate(-2%, 1%); }
  40% { transform: translate(1%, -2%); }
  60% { transform: translate(-1%, 2%); }
  80% { transform: translate(2%, -1%); }
  100% { transform: translate(0, 0); }
}

/* header */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 22px 40px;
  z-index: 50;
  background: linear-gradient(to bottom, rgba(240,232,222,0.85), transparent);
  mix-blend-mode: normal;
}
.brand {
  font-family: 'Libre Baskerville', serif;
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.02em;
  color: var(--basalt);
}
.site-nav {
  display: flex;
  gap: 28px;
}
.site-nav a {
  color: var(--basalt);
  text-decoration: none;
  font-size: 13px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: border-color 0.3s ease;
}
.site-nav a:hover { border-bottom-color: var(--burnt); }

/* mega hero */
.mega-hero {
  height: 150vh;
  background:
    radial-gradient(ellipse at 30% 40%, rgba(212,160,96,0.35) 0%, transparent 60%),
    linear-gradient(160deg, var(--burnt) 0%, var(--canyon-deep) 100%);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  padding: 0 0 0 6vw;
  color: var(--sand);
}
.hero-overline {
  font-size: 13px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  margin-bottom: 32px;
  color: var(--clay);
  position: relative;
  padding-left: 60px;
}
.hero-overline::before {
  content: "";
  position: absolute;
  left: 0; top: 50%;
  width: 44px; height: 1px;
  background: var(--clay);
}
.hero-title {
  font-family: 'Libre Baskerville', serif;
  font-weight: 700;
  font-size: clamp(60px, 18vw, 220px);
  line-height: 0.85;
  letter-spacing: -0.04em;
  white-space: nowrap;
  margin-left: -8vw;
  color: var(--sand);
  text-shadow: 0 4px 0 rgba(42,36,32,0.15);
  position: relative;
}
.hero-sub {
  margin-top: 40px;
  font-size: clamp(16px, 1.7vw, 22px);
  max-width: 540px;
  color: var(--clay);
  font-weight: 400;
  line-height: 1.5;
}
.hero-meta {
  position: absolute;
  bottom: 8vh;
  left: 6vw;
  right: 6vw;
  display: flex;
  gap: 48px;
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--clay);
  border-top: 1px solid rgba(240,232,222,0.3);
  padding-top: 18px;
}

/* section common */
section {
  position: relative;
  padding: 120px 6vw;
  z-index: 1;
}
.section-mark {
  font-size: 12px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--burnt);
  margin-bottom: 32px;
  font-weight: 500;
}
.section-title {
  font-family: 'Libre Baskerville', serif;
  font-weight: 700;
  font-size: clamp(28px, 4vw, 56px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--basalt);
  max-width: 900px;
  margin-bottom: 56px;
}
.section-lede {
  max-width: 620px;
  font-size: clamp(15px, 1.5vw, 18px);
  color: var(--slate);
  margin-bottom: 56px;
}

/* strata */
.strata-section {
  background: var(--clay);
  border-top: 8px solid var(--burnt);
  border-bottom: 4px solid var(--canyon-deep);
}
.strata-stack {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--basalt);
}
.strata-band {
  display: grid;
  grid-template-columns: 140px 1fr 100px;
  align-items: center;
  padding: 36px 24px;
  border-bottom: 1px solid var(--basalt);
  position: relative;
  font-size: clamp(15px, 1.6vw, 19px);
  font-family: 'Libre Baskerville', serif;
  transition: padding-left 0.4s ease;
  cursor: default;
}
.strata-band:hover { padding-left: 48px; }
.strata-band .band-depth {
  font-family: 'Work Sans', sans-serif;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--canyon-deep);
}
.strata-band .band-name {
  font-style: italic;
  color: var(--basalt);
}
.strata-band .band-age {
  font-family: 'Work Sans', sans-serif;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--slate);
  text-align: right;
}
.band-1 { background: linear-gradient(90deg, rgba(196,97,58,0.18), transparent 60%); }
.band-2 { background: linear-gradient(90deg, rgba(212,160,96,0.22), transparent 60%); }
.band-3 { background: linear-gradient(90deg, rgba(138,58,30,0.22), transparent 60%); }
.band-4 { background: linear-gradient(90deg, rgba(106,100,96,0.22), transparent 60%); }

/* fossils */
.fossils-section {
  background: var(--sand);
  border-top: 4px solid var(--burnt);
}
.fossil-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 0;
  border-top: 1px solid var(--basalt);
  border-left: 1px solid var(--basalt);
}
.fossil-panel {
  border-right: 1px solid var(--basalt);
  border-bottom: 1px solid var(--basalt);
  background: var(--sand);
  position: relative;
  overflow: hidden;
  transition: background 0.4s ease;
}
.fossil-panel.is-open { background: var(--clay); }
.fossil-trigger {
  width: 100%;
  border: none;
  background: transparent;
  display: grid;
  grid-template-columns: 80px 1fr 40px;
  align-items: center;
  gap: 16px;
  padding: 26px 28px;
  cursor: pointer;
  text-align: left;
  font-family: 'Work Sans', sans-serif;
  color: var(--basalt);
}
.fossil-num {
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--burnt);
  font-weight: 500;
}
.fossil-label {
  font-family: 'Libre Baskerville', serif;
  font-size: clamp(16px, 1.7vw, 21px);
  font-style: italic;
  font-weight: 400;
}
.fossil-toggle {
  font-family: 'Libre Baskerville', serif;
  font-size: 28px;
  text-align: right;
  color: var(--canyon-deep);
  transition: transform 0.4s ease;
}
.fossil-panel.is-open .fossil-toggle { transform: rotate(45deg); }
.fossil-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.5s cubic-bezier(0.4, 0, 0.2, 1), padding 0.5s ease;
  padding: 0 28px;
  color: var(--basalt);
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.6;
}
.fossil-panel.is-open .fossil-body {
  max-height: 320px;
  padding: 0 28px 32px 108px;
}

/* spark particles */
.spark {
  position: fixed;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--burnt);
  pointer-events: none;
  z-index: 200;
  opacity: 1;
}

/* flow */
.flow-section {
  background: var(--basalt);
  color: var(--sand);
  border-top: 4px solid var(--burnt);
  border-bottom: 8px solid var(--burnt);
}
.flow-section .section-mark { color: var(--ochre); }
.flow-section .section-title { color: var(--sand); }
.quote-block {
  font-family: 'Libre Baskerville', serif;
  font-style: italic;
  font-size: clamp(20px, 2.4vw, 32px);
  line-height: 1.4;
  max-width: 880px;
  border-left: 3px solid var(--burnt);
  padding: 12px 0 12px 32px;
  color: var(--clay);
  margin-bottom: 80px;
}
.flow-numbers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0;
  border-top: 1px solid var(--burnt);
  border-left: 1px solid var(--burnt);
}
.numblock {
  border-right: 1px solid var(--burnt);
  border-bottom: 1px solid var(--burnt);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.num {
  font-family: 'Libre Baskerville', serif;
  font-size: clamp(34px, 4vw, 56px);
  color: var(--ochre);
  line-height: 1;
}
.num-label {
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--clay);
}

/* deposit */
.deposit-section {
  background: var(--clay);
  border-top: 4px solid var(--canyon-deep);
}
.deposit-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px 32px;
  max-width: 760px;
}
.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.field.full { grid-column: 1 / -1; }
.field span {
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--canyon-deep);
}
.field input,
.field textarea {
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--basalt);
  font-family: 'Libre Baskerville', serif;
  font-size: 18px;
  color: var(--basalt);
  padding: 10px 0;
  font-style: italic;
  resize: vertical;
  outline: none;
  transition: border-color 0.3s ease;
}
.field textarea {
  border: 1px solid var(--basalt);
  padding: 12px;
}
.field input:focus,
.field textarea:focus { border-color: var(--burnt); }
.deposit-submit {
  grid-column: 1 / -1;
  justify-self: start;
  background: var(--basalt);
  color: var(--sand);
  border: none;
  padding: 18px 36px;
  font-family: 'Work Sans', sans-serif;
  font-size: 13px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  cursor: pointer;
  transition: background 0.3s ease, transform 0.2s ease;
}
.deposit-submit:hover {
  background: var(--burnt);
  transform: translateY(-2px);
}
.deposit-receipt {
  grid-column: 1 / -1;
  font-family: 'Libre Baskerville', serif;
  font-style: italic;
  color: var(--canyon-deep);
  min-height: 24px;
}

/* footer */
.site-footer {
  background: var(--basalt);
  color: var(--clay);
  padding: 60px 6vw 40px;
}
.footer-line {
  height: 4px;
  background: linear-gradient(90deg, var(--burnt), var(--ochre), var(--canyon-deep));
  margin-bottom: 40px;
}
.footer-cols {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

/* responsive */
@media (max-width: 720px) {
  .site-header { padding: 16px 20px; }
  .site-nav { gap: 14px; }
  .site-nav a { font-size: 11px; }
  .mega-hero { height: 110vh; padding-left: 5vw; }
  .hero-title { margin-left: -4vw; }
  .strata-band { grid-template-columns: 1fr; gap: 6px; padding: 24px 16px; }
  .strata-band .band-age { text-align: left; }
  .deposit-form { grid-template-columns: 1fr; }
  .footer-cols { flex-direction: column; }
  section { padding: 80px 6vw; }
}