/* ============================================================
   CLARK — FIELD REPORT 001
   Industrial dossier: survey paper, ink serif, surveyor orange.
   ============================================================ */

:root {
  --paper: #f4efe4;
  --paper-deep: #ece5d4;
  --ink: #1c1915;
  --ink-soft: #4a443a;
  --ink-faint: #8a8172;
  --accent: #c8480a;          /* surveyor orange */
  --accent-deep: #9c3505;
  --rule: #d8cfba;
  --rule-dark: #1c1915;
  --note-bg: #ede6d3;
  --serif: "Newsreader", Georgia, serif;
  --display: "Instrument Serif", Georgia, serif;
  --mono: "IBM Plex Mono", "Courier New", monospace;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.125rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  /* paper grain */
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='2'/%3E%3CfeColorMatrix values='0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.035 0'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)'/%3E%3C/svg%3E");
}

.mono { font-family: var(--mono); }

a { color: var(--accent-deep); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--accent); }

::selection { background: var(--accent); color: var(--paper); }

/* ============ MASTHEAD ============ */

.masthead {
  border-bottom: 3px double var(--rule-dark);
  background:
    linear-gradient(180deg, rgba(200,72,10,0.04), transparent 40%);
}

.masthead-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 3.5rem 2rem 2.75rem;
}

.masthead-meta {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--ink-soft);
  text-transform: uppercase;
}

.masthead-rule { flex: 1; height: 1px; background: var(--rule-dark); opacity: 0.35; }

.masthead-title {
  font-family: var(--display);
  font-weight: 400;
  font-size: clamp(3rem, 7.5vw, 6.25rem);
  line-height: 0.98;
  letter-spacing: -0.01em;
  margin: 2.25rem 0 1.5rem;
  animation: rise 0.9s cubic-bezier(0.19, 1, 0.22, 1) both;
}

.fr-number {
  display: block;
  font-size: clamp(1.1rem, 2vw, 1.5rem);
  font-family: var(--mono);
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.4rem;
}
.fr-number em { font-style: normal; border-bottom: 2px solid var(--accent); padding-bottom: 2px; }

.masthead-dek {
  max-width: 44ch;
  font-size: 1.2rem;
  line-height: 1.55;
  color: var(--ink-soft);
  font-style: italic;
  animation: rise 0.9s 0.12s cubic-bezier(0.19, 1, 0.22, 1) both;
}

.masthead-stamp {
  display: inline-flex;
  gap: 0;
  margin-top: 2rem;
  border: 1.5px solid var(--accent-deep);
  color: var(--accent-deep);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  transform: rotate(-1.2deg);
  animation: rise 0.9s 0.24s cubic-bezier(0.19, 1, 0.22, 1) both;
}
.masthead-stamp span {
  padding: 0.4rem 0.9rem;
  border-right: 1.5px solid var(--accent-deep);
}
.masthead-stamp span:last-child { border-right: none; }

@keyframes rise {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}
.masthead-stamp { animation-name: rise-stamp; }
@keyframes rise-stamp {
  from { opacity: 0; transform: rotate(-1.2deg) translateY(18px); }
  to   { opacity: 1; transform: rotate(-1.2deg) translateY(0); }
}

/* ============ PAGE GRID ============ */

.page {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 215px minmax(0, 1fr) 250px;
  gap: 3.5rem;
  padding: 0 2rem;
}

/* ============ RAILS (shared) ============ */

.rail {
  padding-top: 3.5rem;
  font-size: 0.85rem;
}

.rail-title {
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink);
  border-bottom: 2px solid var(--rule-dark);
  padding-bottom: 0.6rem;
  margin-bottom: 1.1rem;
}

.rail-foot {
  margin-top: 2.5rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--rule);
  font-size: 0.68rem;
  line-height: 1.7;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
}

/* ---- left rail: section index (the spine) ---- */

.rail-left { position: sticky; top: 0; align-self: start; max-height: 100vh; overflow-y: auto; }

.section-index { list-style: none; }

.section-index a {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  padding: 0.55rem 0.6rem 0.55rem 0.75rem;
  text-decoration: none;
  color: var(--ink-soft);
  font-family: var(--display);
  font-size: 1.06rem;
  line-height: 1.25;
  border-left: 2px solid transparent;
  transition: color 0.18s, border-color 0.18s, background 0.18s, padding-left 0.18s;
}

.section-index .idx {
  font-size: 0.66rem;
  color: var(--ink-faint);
  letter-spacing: 0.08em;
  transition: color 0.18s;
}

.section-index a:hover {
  color: var(--ink);
  border-left-color: var(--rule-dark);
}

.section-index a.active {
  color: var(--accent-deep);
  border-left-color: var(--accent);
  background: linear-gradient(90deg, rgba(200,72,10,0.07), transparent);
  padding-left: 1rem;
}
.section-index a.active .idx { color: var(--accent); }

/* ---- figures: interlaid field imagery, dossier register ---- */

.figure {
  margin: 2.4rem 0;
  padding: 0.6rem;
  border: 1px solid var(--rule-dark);
  background: rgba(255, 253, 247, 0.55);
}

.figure img {
  display: block;
  width: 100%;
  height: auto;
  filter: saturate(0.82) contrast(1.03);
}

.figure figcaption {
  padding: 0.65rem 0.2rem 0.1rem;
  font-size: 0.68rem;
  line-height: 1.65;
  letter-spacing: 0.03em;
  color: var(--ink-soft);
}

.figure .fig-credit {
  color: var(--ink-faint);
  display: block;
  margin-top: 0.15rem;
}

.figure-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.6rem;
}
.figure-pair .fig-cell { min-width: 0; }
.figure-pair .fig-cell img { height: 100%; object-fit: cover; }
.figure-pair figcaption { grid-column: 1 / -1; }

.figure-wide {
  margin-left: -1.5rem;
  margin-right: -1.5rem;
}

@media (max-width: 720px) {
  .figure-pair { grid-template-columns: 1fr; }
  .figure-wide { margin-left: 0; margin-right: 0; }
}

/* ---- left rail: working papers (beneath the spine) ---- */

.papers-block {
  margin-top: 2.4rem;
  padding-top: 1rem;
  border-top: 2px solid var(--rule-dark);
}

.papers-title {
  font-size: 0.64rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-deep);
  margin-bottom: 0.45rem;
}

.papers-note {
  font-size: 0.78rem;
  font-style: italic;
  line-height: 1.5;
  color: var(--ink-faint);
  margin-bottom: 0.9rem;
}

.papers-list { list-style: none; }

.papers-list a {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  padding: 0.4rem 0.6rem 0.4rem 0.75rem;
  text-decoration: none;
  color: var(--ink-soft);
  font-family: var(--display);
  font-size: 0.98rem;
  line-height: 1.3;
  border-left: 2px solid transparent;
  transition: color 0.18s, border-color 0.18s;
}

.papers-list .wp {
  font-size: 0.6rem;
  color: var(--ink-faint);
  letter-spacing: 0.08em;
}

.papers-list a:hover {
  color: var(--accent-deep);
  border-left-color: var(--accent);
}
.papers-list a:hover .wp { color: var(--accent); }

/* ---- document overlay: working papers in a raw-file viewer ---- */

.paper-overlay {
  width: min(940px, 94vw);
  height: min(92vh, 1100px);
  border: 2px solid var(--ink);
  background: var(--paper);
  padding: 0;
  box-shadow: 10px 10px 0 rgba(28, 25, 21, 0.25);
}

.paper-overlay::backdrop {
  background: rgba(28, 25, 21, 0.55);
  backdrop-filter: blur(2px);
}

.overlay-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: 2.4rem;
  padding: 0 0.9rem;
  background: var(--ink);
  color: var(--paper);
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.overlay-title {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.overlay-close {
  background: none;
  border: none;
  color: var(--paper);
  font: inherit;
  letter-spacing: 0.14em;
  cursor: pointer;
  padding: 0.3rem 0;
  flex-shrink: 0;
  transition: color 0.18s;
}
.overlay-close:hover { color: var(--accent); }

.paper-overlay iframe {
  display: block;
  width: 100%;
  height: calc(100% - 2.4rem);
  border: none;
  background: #f8f4e9;
}

/* ---- right rail: sources (lighter register) ---- */

.rail-right { position: sticky; top: 0; align-self: start; max-height: 100vh; overflow-y: auto; padding-bottom: 3rem; }

.rail-right .rail-title {
  border-bottom: 1px solid var(--rule);
  color: var(--ink-faint);
}

.src-group { margin-bottom: 1.6rem; }

.src-head {
  font-size: 0.64rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent-deep);
  margin-bottom: 0.55rem;
  opacity: 0.85;
}

.src-list { list-style: none; }

.src-list li { margin-bottom: 0.55rem; }

.src-list a {
  display: block;
  font-family: var(--serif);
  font-size: 0.86rem;
  line-height: 1.4;
  color: var(--ink-soft);
  text-decoration: none;
  padding-left: 0.75rem;
  border-left: 1px solid var(--rule);
  transition: color 0.15s, border-color 0.15s;
}

.src-list a:hover { color: var(--accent-deep); border-left-color: var(--accent); }

.src-note {
  display: block;
  font-family: var(--mono);
  font-size: 0.62rem;
  letter-spacing: 0.05em;
  color: var(--ink-faint);
  margin-top: 0.1rem;
}

.src-group-clark {
  background: var(--note-bg);
  border: 1px solid var(--rule);
  padding: 0.9rem 0.85rem 0.5rem;
}
.src-instrument { font-weight: 600; color: var(--accent-deep) !important; }

/* ============ ARTICLE ============ */

.article {
  max-width: 68ch;
  padding: 3.5rem 0 5rem;
  justify-self: center;
  width: 100%;
}

.article-section { margin-bottom: 4.25rem; }

.article p { margin-bottom: 1.4rem; }

.opening-line {
  font-family: var(--display);
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  line-height: 1.3;
  margin-bottom: 2rem !important;
}
.opening-line::first-letter {
  color: var(--accent);
}

h2 {
  font-family: var(--display);
  font-weight: 400;
  font-size: clamp(2rem, 4vw, 2.7rem);
  line-height: 1.08;
  margin: 0 0 1.75rem;
  padding-top: 2.5rem;
  border-top: 2px solid var(--rule-dark);
  display: flex;
  align-items: baseline;
  gap: 1rem;
}

.sec-no {
  font-size: 0.95rem;
  color: var(--accent);
  letter-spacing: 0.1em;
  flex-shrink: 0;
}

h3 {
  font-family: var(--display);
  font-weight: 400;
  font-style: italic;
  font-size: 1.65rem;
  margin: 2.6rem 0 1rem;
}
h3::before {
  content: "— ";
  color: var(--accent);
  font-style: normal;
}

blockquote {
  margin: 2rem 0;
  padding: 1.4rem 1.6rem;
  border-left: 3px solid var(--accent);
  background: var(--note-bg);
}
blockquote p {
  font-style: italic;
  font-size: 1.15rem;
  margin-bottom: 0.8rem !important;
}
blockquote cite {
  font-style: normal;
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.isolated-line {
  font-family: var(--display);
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  line-height: 1.1;
  text-align: center;
  margin: 3rem 0 !important;
  color: var(--accent-deep);
}
.isolated-line::before, .isolated-line::after {
  content: "";
  display: block;
  width: 56px;
  height: 2px;
  background: var(--accent);
  margin: 1.1rem auto;
}

.protocol-line {
  font-size: 0.92rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-align: center;
  padding: 1.1rem 1rem;
  margin: 1.8rem 0 !important;
  border-top: 1px solid var(--rule-dark);
  border-bottom: 1px solid var(--rule-dark);
  color: var(--accent-deep);
}

.address { padding-left: 1.4rem; border-left: 1px solid var(--rule-dark); }

.sign-off {
  font-family: var(--display);
  font-style: italic;
  font-size: 1.4rem;
  margin-top: 2.6rem !important;
}

/* ---- field placeholders ---- */

.field-placeholder {
  margin: 1.8rem 0;
  padding: 1rem 1.2rem;
  border: 1.5px dashed var(--ink-faint);
  color: var(--ink-faint);
  font-size: 0.78rem;
  line-height: 1.6;
}
.fp-tag {
  display: inline-block;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--accent);
  margin-bottom: 0.35rem;
}

/* ---- annotations ---- */

.note-ref {
  font-size: 0.66rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--paper);
  background: var(--accent);
  border: none;
  padding: 0.12rem 0.42rem 0.16rem;
  margin-left: 0.45rem;
  vertical-align: super;
  line-height: 1;
  cursor: pointer;
  border-radius: 1px;
  transition: background 0.15s, transform 0.15s;
}
.note-ref:hover { background: var(--accent-deep); transform: translateY(-1px); }
.note-ref[aria-expanded="true"] { background: var(--ink); }

.annotation {
  margin: 0 0 1.6rem;
  padding: 1.15rem 1.35rem 1.05rem;
  background: var(--note-bg);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--ink);
  font-size: 0.96rem;
  line-height: 1.6;
  color: var(--ink-soft);
  animation: noteOpen 0.3s cubic-bezier(0.19, 1, 0.22, 1);
}
.annotation p { margin-bottom: 0.75rem; }
.annotation p:last-child { margin-bottom: 0; }

.annotation-label {
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-deep);
  margin-bottom: 0.55rem !important;
}

@keyframes noteOpen {
  from { opacity: 0; transform: translateY(-6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ---- article footer ---- */

.article-footer {
  margin-top: 4rem;
  padding-top: 1.6rem;
  border-top: 3px double var(--rule-dark);
  text-align: center;
}
.article-footer p { margin-bottom: 0.7rem; }
.article-footer .mono {
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  color: var(--accent-deep);
}
.article-footer p:nth-child(2) {
  font-style: italic;
  color: var(--ink-soft);
  max-width: 42ch;
  margin: 0 auto 0.9rem;
}
.article-footer .small { font-size: 0.62rem; color: var(--ink-faint); }

/* ============ RESPONSIVE ============ */

@media (max-width: 1080px) {
  .page { grid-template-columns: 190px minmax(0, 1fr); gap: 2.5rem; }
  .rail-right {
    position: static;
    grid-column: 1 / -1;
    max-height: none;
    border-top: 2px solid var(--rule-dark);
    padding-top: 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    column-gap: 2.5rem;
  }
  .rail-right .rail-title { grid-column: 1 / -1; border-bottom: none; }
  .rail-right .rail-foot { grid-column: 1 / -1; }
}

@media (max-width: 720px) {
  .page { grid-template-columns: 1fr; gap: 0; padding: 0 1.25rem; }
  .rail-left {
    position: static;
    max-height: none;
    padding-top: 2.25rem;
  }
  .section-index a { padding: 0.4rem 0.5rem; font-size: 1rem; }
  .article { padding-top: 2.25rem; }
  .masthead-inner { padding: 2.5rem 1.25rem 2rem; }
  body { font-size: 1.05rem; }
}