/* ============ SPINE / FABRIC / SIGNALS shared structural styles ============ */

/* Hero (works for /spine, /fabric, /signals) */
.struct-hero{
  position: relative;
  padding: clamp(120px, 18vh, 220px) 0 clamp(72px, 10vh, 120px);
  border-bottom: 1px solid var(--rule);
  overflow: hidden;
}
.struct-hero .wrap{ position: relative; z-index: 1; }
.struct-hero .domain{
  font-size: 12px; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--green); font-weight: 500;
  display: inline-flex; align-items: center; gap: 10px;
  margin-bottom: 36px;
}
.struct-hero .domain .tick{ width: 22px; height: 1px; background: var(--green); }
.struct-hero h1{
  font-family: var(--serif);
  font-size: clamp(56px, 8.4vw, 128px);
  line-height: 0.98; letter-spacing: -0.028em;
  color: var(--ink);
  max-width: 16ch;
  margin: 0 0 32px;
}
.struct-hero .lede{
  font-family: var(--serif);
  font-size: clamp(22px, 2.2vw, 30px);
  line-height: 1.4; color: var(--muted);
  max-width: 38ch;
  font-style: italic;
  margin: 0;
}
.struct-hero .secondary{
  margin-top: 40px; padding-top: 28px;
  border-top: 1px solid var(--rule);
  display: flex; justify-content: space-between;
  align-items: baseline; gap: 24px; flex-wrap: wrap;
}
.struct-hero .secondary .note{
  font-family: var(--serif); font-style: italic;
  color: var(--muted); font-size: 17px; max-width: 42ch;
}
.struct-hero .secondary .read{
  display: inline-flex; align-items: center; gap: 12px;
  font-size: 12.5px; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--muted);
}
.struct-hero .secondary .read .arrow-down{
  width: 1px; height: 28px; background: var(--green);
  position: relative;
}
.struct-hero .secondary .read .arrow-down::after{
  content: ""; position: absolute; bottom: 0; left: -3px;
  width: 7px; height: 7px;
  border-bottom: 1px solid var(--green);
  border-right: 1px solid var(--green);
  transform: rotate(45deg);
}

/* Numbered structural sections — i. ii. iii. — used across Spine, Fabric, Signals */
.struct-section{
  position: relative;
  padding: clamp(80px, 12vh, 140px) 0;
  border-bottom: 1px solid var(--rule);
}
.struct-section:last-of-type{ border-bottom: 0; }

.struct-grid{
  display: grid; grid-template-columns: 1fr; gap: 32px;
}
@media (min-width: 920px){
  .struct-grid{ grid-template-columns: 200px minmax(0, 1fr); gap: 80px; align-items: start; }
}
.struct-grid .label{
  font-family: var(--serif); font-style: italic;
  color: var(--green); font-size: 17px;
  position: sticky; top: 96px;
}
.struct-grid .label .name{
  display: block; font-family: var(--sans); font-style: normal;
  color: var(--muted); font-size: 11.5px; letter-spacing: 0.14em;
  text-transform: uppercase; margin-top: 8px;
}
@media (max-width: 919px){ .struct-grid .label{ position: static; } }

.struct-content h2{
  font-size: clamp(30px, 3.6vw, 48px); line-height: 1.1;
  letter-spacing: -0.015em; max-width: 18ch;
  margin: 0 0 28px;
}
.struct-content p{
  color: var(--ink-2);
  font-size: 17px; line-height: 1.65;
  max-width: 52ch;
  margin: 0 0 16px;
}
.struct-content p + p{ margin-top: 16px; }
.struct-content p.muted{ color: var(--muted); }
.struct-content p.statement{
  font-family: var(--serif); font-style: italic;
  color: var(--ink); font-size: clamp(20px, 2vw, 26px);
  line-height: 1.4; max-width: 40ch;
  margin: 24px 0;
}
.struct-content ul.lines{
  list-style: none; padding: 0; margin: 18px 0 24px;
  display: flex; flex-direction: column; gap: 10px;
  border-left: 1px solid var(--green-soft);
  padding-left: 24px;
}
.struct-content ul.lines li{
  font-family: var(--serif); font-size: 18px; color: var(--ink);
  line-height: 1.4;
}
.struct-content ul.bullets{
  list-style: none; padding: 0; margin: 18px 0 24px;
  display: flex; flex-direction: column; gap: 10px;
}
.struct-content ul.bullets li{
  position: relative; padding-left: 24px;
  font-size: 16px; color: var(--ink-2); line-height: 1.55;
}
.struct-content ul.bullets li::before{
  content: ""; position: absolute; left: 0; top: 12px;
  width: 12px; height: 1px; background: var(--green);
}

/* The four pillars (Spine §iv) */
.pillars{
  display: grid; grid-template-columns: 1fr; gap: 1px;
  background: var(--rule);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  margin: 32px 0;
}
@media (min-width: 760px){ .pillars{ grid-template-columns: 1fr 1fr; } }
.pillars .p{
  background: var(--ivory);
  padding: 36px 32px 40px;
  display: flex; flex-direction: column; gap: 8px;
  min-height: 200px;
}
.pillars .p .roman{
  font-family: var(--serif); font-style: italic;
  color: var(--green); font-size: 14px;
  margin-bottom: 10px;
}
.pillars .p h3{
  font-family: var(--serif); font-size: 28px;
  letter-spacing: -0.01em; line-height: 1.1; margin: 0 0 6px;
}
.pillars .p .where{
  font-family: var(--sans); font-size: 13px;
  color: var(--muted); letter-spacing: 0.04em;
  text-transform: uppercase; margin-bottom: 14px;
}
.pillars .p p{ color: var(--muted); font-size: 15px; line-height: 1.6; margin: 0; max-width: 32ch; }

/* Closing band */
.struct-closing{
  padding: clamp(100px, 16vh, 160px) 0 clamp(80px, 12vh, 120px);
  text-align: center;
  background: var(--ivory-2);
  border-top: 1px solid var(--rule);
}
.struct-closing h2{
  font-size: clamp(36px, 5vw, 64px); line-height: 1.06;
  letter-spacing: -0.02em; max-width: 22ch;
  margin: 0 auto 20px;
}
.struct-closing p{
  font-family: var(--serif); font-style: italic;
  color: var(--muted); font-size: 19px;
  max-width: 42ch; margin: 0 auto 32px;
}
.struct-closing .links{
  display: inline-flex; gap: 32px; flex-wrap: wrap; justify-content: center;
}

/* simple text link with arrow — for signals/Spine in-flow CTAs */
.text-link{
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--ink); font-size: 15.5px;
  border-bottom: 1px solid var(--rule);
  padding: 4px 0;
  transition: color .25s ease, border-color .25s ease;
}
.text-link:hover{ color: var(--green); border-color: var(--green); }
.text-link .arr{
  width: 14px; height: 1px; background: currentColor; position: relative;
  transition: width .25s ease;
}
.text-link .arr::after{
  content: ""; position: absolute; right: 0; top: -3px;
  width: 7px; height: 7px;
  border-right: 1px solid currentColor; border-top: 1px solid currentColor;
  transform: rotate(45deg);
}
.text-link:hover .arr{ width: 22px; }

/* Spine-specific: a section that emphasizes the continuity (§iii) */
.continuity-section{
  position: relative;
  padding: clamp(72px, 11vh, 120px) 0;
  background:
    linear-gradient(to right, transparent 0, transparent 50%, transparent 100%),
    var(--ivory);
}
.continuity-section .pillar-line{
  position: absolute; left: 50%; top: 0; bottom: 0;
  width: 1px; background: linear-gradient(to bottom, transparent, var(--green) 18%, var(--green) 82%, transparent);
  opacity: .5; transform: translateX(-50%);
}
.continuity-section .col{
  position: relative; z-index: 1;
  max-width: 56ch; margin: 0 auto;
}

/* Surface trio for /spine §vi (Expression) */
.surface-trio{
  display: grid; grid-template-columns: 1fr; gap: 16px;
  margin: 28px 0 8px;
}
@media (min-width: 720px){ .surface-trio{ grid-template-columns: repeat(3, 1fr); } }
.surface-trio a.s{
  display: flex; flex-direction: column; gap: 6px;
  padding: 24px 22px;
  background: var(--ivory);
  border: 1px solid var(--rule);
  border-radius: 14px;
  transition: border-color .25s ease, transform .25s ease, background .25s ease;
}
.surface-trio a.s:hover{
  border-color: var(--green-soft);
  background: var(--green-tint);
  transform: translateY(-2px);
}
.surface-trio a.s .name{
  font-family: var(--serif); font-size: 22px; color: var(--ink);
}
.surface-trio a.s .domain{
  font-size: 12px; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--muted);
}

/* Stub page (small placeholder for Fabric/Signals before they're built in full) */
.stub{
  padding: clamp(120px, 22vh, 240px) 0 clamp(100px, 18vh, 200px);
  border-bottom: 1px solid var(--rule);
}
.stub .domain{
  font-size: 12px; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--green); font-weight: 500;
  display: inline-flex; align-items: center; gap: 10px;
  margin-bottom: 36px;
}
.stub .domain .tick{ width: 22px; height: 1px; background: var(--green); }
.stub h1{
  font-family: var(--serif);
  font-size: clamp(56px, 8.4vw, 120px);
  line-height: 0.98; letter-spacing: -0.028em;
  margin: 0 0 28px; max-width: 16ch;
}
.stub .lede{
  font-family: var(--serif); font-style: italic;
  font-size: clamp(20px, 2vw, 26px); line-height: 1.45;
  color: var(--muted); max-width: 44ch; margin: 0 0 40px;
}
.stub .coming{
  display: inline-flex; align-items: center; gap: 12px;
  font-size: 12px; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--green); font-weight: 500;
  padding: 14px 18px;
  border: 1px solid var(--green-soft);
  border-radius: 999px;
  background: var(--green-tint);
}
.stub .return{
  margin-top: 48px;
  display: flex; gap: 32px; flex-wrap: wrap;
  border-top: 1px solid var(--rule);
  padding-top: 28px;
}