/* =========================================================================
   EarthObs — Observations de la Terre · earthobs.com
   Editorial design: warm paper, earth tones, Fraunces + Alegreya Sans.
   Light tokens on :root, dark tokens via prefers-color-scheme.
   ========================================================================= */

:root {
  --paper: #F3ECDF;
  --paper-2: #EAE0CF;
  --card: #FAF6EE;
  --ink: #2A1E16;
  --ink-2: #4A3A2E;
  --muted: #6E5D4F;
  --line: rgba(42, 30, 22, 0.16);
  --line-strong: rgba(42, 30, 22, 0.38);
  --terra: #A6461F;        /* text-safe terracotta (5:1 on paper) */
  --terra-ink: #FFF8EE;    /* text on terracotta fills */
  --olive: #56642E;
  --ochre: #C28A2C;        /* decorative only, never body text */
  --ochre-soft: #E9CF97;
  --band: #2E2219;
  --band-ink: #F3ECDF;
  --band-muted: #CDBFAD;
  --tag-bg: #DDE3C8;
  --tag-ink: #3E4A1E;

  --f-display: "Fraunces", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --f-text: "Alegreya Sans", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  --f-caps: "Alegreya Sans SC", "Alegreya Sans", "Segoe UI", Arial, sans-serif;

  --wrap: 1180px;
  --gutter: clamp(16px, 4vw, 40px);
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #1A1511;
    --paper-2: #221B16;
    --card: #261E18;
    --ink: #F0E7D9;
    --ink-2: #D6C8B6;
    --muted: #A8998A;
    --line: rgba(240, 231, 217, 0.14);
    --line-strong: rgba(240, 231, 217, 0.32);
    --terra: #E3875C;
    --terra-ink: #1A1511;
    --olive: #AEBB74;
    --ochre: #E2B560;
    --ochre-soft: #4A3A1E;
    --band: #0F0C09;
    --band-ink: #F0E7D9;
    --band-muted: #BFB1A0;
    --tag-bg: #333A22;
    --tag-ink: #D5DDB0;
    color-scheme: dark;
  }
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--f-text);
  font-size: 1.1875rem;
  line-height: 1.55;
  font-kerning: normal;
  -webkit-font-smoothing: antialiased;
}
img, svg { max-width: 100%; display: block; }
a { color: var(--terra); text-underline-offset: 0.18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
p { margin: 0 0 1em; }
h1, h2, h3 { font-family: var(--f-display); font-weight: 400; margin: 0; color: var(--ink); }
ul, ol { margin: 0; padding: 0; }
:focus-visible { outline: 3px solid var(--terra); outline-offset: 3px; border-radius: 2px; }

.wrap { max-width: var(--wrap); margin-inline: auto; padding-inline: var(--gutter); }
.sr-only {
  position: absolute !important; width: 1px; height: 1px; margin: -1px; padding: 0;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 100;
  background: var(--terra); color: var(--terra-ink);
  padding: 10px 16px; border-radius: 2px; font-weight: 700; text-decoration: none;
}
.skip-link:focus { top: 12px; }

.kicker {
  font-family: var(--f-caps); font-weight: 500; font-size: 0.9375rem;
  letter-spacing: 0.08em; color: var(--terra); margin: 0 0 0.9rem;
  text-transform: lowercase;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.5em;
  min-height: 48px; padding: 0.7em 1.35em;
  font-family: var(--f-text); font-weight: 700; font-size: 1.0625rem; line-height: 1.1;
  border-radius: 2px; border: 1.5px solid transparent; text-decoration: none; cursor: pointer;
  transition: background-color .2s ease, color .2s ease, border-color .2s ease;
}
.btn-primary { background: var(--terra); color: var(--terra-ink); }
.btn-primary:hover { background: color-mix(in srgb, var(--terra) 86%, var(--ink)); }
.btn-ghost { border-color: var(--line-strong); color: var(--ink); background: transparent; }
.btn-ghost:hover { border-color: var(--ink); }
.btn-sm { min-height: 40px; padding: 0.5em 1em; font-size: 1rem; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: saturate(1.2) blur(8px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 72px; }
.brand { text-decoration: none; color: var(--ink); display: flex; flex-direction: column; line-height: 1; }
.wordmark { font-family: var(--f-display); font-weight: 600; font-size: 1.75rem; letter-spacing: -0.01em; }
.wordmark em { font-style: italic; font-weight: 400; color: var(--terra); }
.baseline { font-family: var(--f-caps); font-size: 0.8125rem; letter-spacing: 0.08em; color: var(--muted); margin-top: 4px; text-transform: lowercase; }
.site-nav { display: flex; align-items: center; gap: clamp(14px, 2vw, 28px); }
.site-nav a:not(.btn) { color: var(--ink-2); text-decoration: none; font-size: 1.0625rem; }
.site-nav a:not(.btn):hover { color: var(--terra); }
.nav-toggle {
  display: none; font: inherit; font-weight: 700; font-size: 1rem;
  background: none; color: var(--ink); border: 1.5px solid var(--line-strong);
  border-radius: 2px; min-height: 44px; padding: 0 14px; cursor: pointer;
}

/* ---------- Hero ---------- */
.hero { padding-block: clamp(48px, 8vw, 104px) clamp(32px, 5vw, 56px); }
.hero-grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 4fr); gap: clamp(32px, 6vw, 88px); align-items: end; }
.hero h1 {
  font-size: clamp(2.75rem, 7vw, 5.75rem);
  line-height: 0.98; letter-spacing: -0.02em; font-weight: 350;
  font-variation-settings: "opsz" 144;
}
.hero h1 em { font-style: italic; color: var(--terra); font-weight: 300; }
.lede { font-size: clamp(1.1875rem, 1.6vw, 1.375rem); color: var(--ink-2); max-width: 36rem; margin-top: 1.5rem; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 2rem; }

.sommaire { border-top: 3px double var(--line-strong); padding-top: 1rem; }
.sommaire h2 { font-family: var(--f-caps); font-size: 0.9375rem; letter-spacing: 0.08em; color: var(--muted); text-transform: lowercase; font-weight: 500; margin-bottom: 0.5rem; }
.sommaire ol { list-style: none; counter-reset: s; }
.sommaire li { counter-increment: s; border-bottom: 1px solid var(--line); }
.sommaire a {
  display: grid; grid-template-columns: 2.2rem 1fr; gap: 0.5rem; align-items: baseline;
  padding: 0.6rem 0; color: var(--ink); text-decoration: none; font-size: 1.0625rem;
}
.sommaire a::before { content: counter(s, upper-roman) "."; font-family: var(--f-display); font-style: italic; color: var(--terra); }
.sommaire a:hover span { text-decoration: underline; text-underline-offset: 0.18em; }
.sommaire small { display: block; color: var(--muted); font-size: 0.9375rem; }

.relief { margin: clamp(40px, 6vw, 72px) 0 0; }
.relief-frame { border-block: 1px solid var(--line-strong); aspect-ratio: 4 / 1; overflow: hidden; background: var(--paper-2); }
.relief-frame img { width: 100%; height: 100%; object-fit: cover; }
.relief figcaption { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 0.9375rem; color: var(--muted); padding-top: 0.6rem; }
.relief figcaption span:first-child { font-style: italic; }

/* ---------- Sections ---------- */
.section { padding-block: clamp(64px, 9vw, 120px); border-top: 1px solid var(--line); }
.section-head { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 7fr); gap: clamp(24px, 5vw, 72px); margin-bottom: clamp(36px, 5vw, 60px); align-items: end; }
.section-head h2 { font-size: clamp(2rem, 4.2vw, 3.25rem); line-height: 1.04; letter-spacing: -0.015em; font-variation-settings: "opsz" 120; }
.section-head h2 em { font-style: italic; color: var(--terra); }
.section-intro { color: var(--ink-2); font-size: 1.25rem; margin: 0; max-width: 40rem; }
.dropcap::first-letter {
  float: left; font-family: var(--f-display); font-weight: 600; color: var(--terra);
  font-size: 3.6em; line-height: 0.82; padding: 0.06em 0.1em 0 0;
}

/* ---------- Services (three columns with rules) ---------- */
.services { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); }
.service { padding: 0 clamp(18px, 2.6vw, 36px); border-left: 1px solid var(--line-strong); }
.service:first-child { padding-left: 0; border-left: 0; }
.service-num { font-family: var(--f-display); font-style: italic; font-size: 2.5rem; line-height: 1; color: var(--ochre); display: block; margin-bottom: 0.6rem; }
.service h3 { font-size: 1.75rem; line-height: 1.1; margin-bottom: 0.8rem; }
.service p { color: var(--ink-2); }
.service ul { list-style: none; border-top: 1px solid var(--line); }
.service li { padding: 0.45rem 0 0.45rem 1.2rem; border-bottom: 1px solid var(--line); position: relative; font-size: 1.0625rem; }
.service li::before { content: "–"; position: absolute; left: 0; color: var(--terra); }

/* ---------- Guide ---------- */
.guide { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 7fr); gap: clamp(24px, 4vw, 56px); align-items: start; }
.guide-aside p { color: var(--ink-2); }
.guide-aside .note { font-size: 1rem; color: var(--muted); border-top: 1px solid var(--line); padding-top: 0.8rem; margin-top: 1.2rem; }

/* No-JS: questions as <details> */
.guide-list { grid-column: 1 / -1; border-top: 1px solid var(--line-strong); }
.guide-item .guide-answer h3 { display: none; } /* the summary already shows the question */
.guide-item { border-bottom: 1px solid var(--line-strong); }
.guide-item > summary {
  list-style: none; cursor: pointer; padding: 1rem 2.4rem 1rem 0; position: relative;
  font-family: var(--f-display); font-size: 1.375rem; line-height: 1.2;
}
.guide-item > summary::-webkit-details-marker { display: none; }
.guide-item > summary::after { content: "+"; position: absolute; right: 0.4rem; top: 0.9rem; color: var(--terra); font-family: var(--f-text); font-size: 1.5rem; }
.guide-item[open] > summary::after { content: "–"; }
.guide-item .guide-answer { padding-bottom: 1.4rem; }
.q-num { font-family: var(--f-caps); font-size: 0.875rem; letter-spacing: 0.06em; color: var(--terra); display: block; margin-bottom: 2px; text-transform: lowercase; }

/* Enhanced: tab list + one panel */
.guide-tabs { display: flex; flex-direction: column; border-top: 1px solid var(--line-strong); }
.guide-tab {
  font: inherit; text-align: left; cursor: pointer; background: none; color: var(--ink);
  border: 0; border-bottom: 1px solid var(--line); padding: 0.8rem 1rem 0.8rem 0.9rem;
  font-family: var(--f-display); font-size: 1.1875rem; line-height: 1.2;
  border-left: 3px solid transparent; transition: background-color .15s ease, border-color .15s ease;
}
.guide-tab:hover { background: color-mix(in srgb, var(--terra) 7%, transparent); }
.guide-tab[aria-selected="true"] { border-left-color: var(--terra); background: var(--card); }
.guide-tab .q-num { margin-bottom: 0; }
.guide-panels .guide-answer {
  background: var(--card); border: 1px solid var(--line-strong); border-top: 3px solid var(--terra);
  padding: clamp(20px, 3vw, 36px);
}
.guide-answer h3 { font-size: clamp(1.5rem, 2.6vw, 2rem); line-height: 1.12; margin-bottom: 1.2rem; }
.guide-answer dl { display: grid; grid-template-columns: minmax(8.5rem, 1fr) minmax(0, 2.6fr); margin: 0; border-top: 1px solid var(--line); }
.guide-answer dt, .guide-answer dd { padding: 0.6rem 0; border-bottom: 1px solid var(--line); margin: 0; }
.guide-answer dt { font-family: var(--f-caps); font-size: 0.9375rem; letter-spacing: 0.05em; color: var(--muted); text-transform: lowercase; padding-right: 1rem; }
.guide-answer dd { color: var(--ink-2); }
.guide-answer dd strong { color: var(--ink); font-weight: 700; }
.caution {
  margin: 1.2rem 0 0; padding: 0.8rem 1rem; border-left: 3px solid var(--ochre);
  background: color-mix(in srgb, var(--ochre-soft) 45%, transparent); font-style: italic; color: var(--ink-2); font-size: 1.0625rem;
}
.caution b { font-style: normal; font-family: var(--f-caps); letter-spacing: 0.05em; color: var(--ink); text-transform: lowercase; font-weight: 500; }
.guide-ask { display: inline-block; margin-top: 1.1rem; font-weight: 700; }

/* ---------- Publics ---------- */
.publics { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(28px, 4vw, 48px) clamp(24px, 4vw, 56px); }
.public { border-top: 2px solid var(--ink); padding-top: 0.9rem; }
.public h3 { font-size: 1.5rem; line-height: 1.15; margin-bottom: 0.5rem; }
.public p { color: var(--ink-2); margin: 0; font-size: 1.125rem; }

/* ---------- Data table ---------- */
.table-scroll { overflow-x: auto; border-block: 1px solid var(--line-strong); }
.data-table { width: 100%; min-width: 780px; border-collapse: collapse; font-size: 1.0625rem; }
.data-table caption { text-align: left; }
.data-table th, .data-table td { text-align: left; padding: 13px 16px 13px 0; border-bottom: 1px solid var(--line); vertical-align: baseline; }
.data-table thead th { font-family: var(--f-caps); font-weight: 500; font-size: 0.9375rem; letter-spacing: 0.06em; color: var(--muted); text-transform: lowercase; }
.data-table tbody th { font-family: var(--f-display); font-weight: 500; font-size: 1.125rem; }
.data-table tbody th span { display: block; font-family: var(--f-text); font-weight: 400; font-size: 0.9375rem; color: var(--muted); }
.data-table td { color: var(--ink-2); }
.data-table .num { font-variant-numeric: tabular-nums lining-nums; color: var(--ink); white-space: nowrap; font-weight: 500; }
.data-table tbody tr:last-child th, .data-table tbody tr:last-child td { border-bottom: 0; }
.data-table tbody tr.group-row th {
  font-family: var(--f-caps); font-weight: 500; font-size: 0.9375rem; letter-spacing: 0.06em;
  color: var(--terra); text-transform: lowercase;
  padding-top: 24px; padding-bottom: 8px; border-top: 1px solid var(--line-strong); border-bottom: 1px solid var(--line-strong);
}
.tag {
  display: inline-block; font-family: var(--f-caps); font-size: 0.875rem; letter-spacing: 0.05em; text-transform: lowercase;
  padding: 2px 9px; border: 1px solid var(--line-strong); border-radius: 999px; color: var(--ink-2); white-space: nowrap;
}
.tag-open { background: var(--tag-bg); color: var(--tag-ink); border-color: transparent; }
.footnote { margin-top: 14px; font-size: 1rem; color: var(--muted); max-width: 52rem; }

/* ---------- Method ---------- */
.method { list-style: none; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 0; counter-reset: m; border-top: 1px solid var(--line-strong); }
.method li { counter-increment: m; padding: 1.2rem clamp(12px, 1.6vw, 22px) 0 0; border-right: 1px solid var(--line); }
.method li + li { padding-left: clamp(12px, 1.6vw, 22px); }
.method li:last-child { border-right: 0; }
.method li::before { content: counter(m, decimal-leading-zero); display: block; font-family: var(--f-display); font-size: 2.75rem; line-height: 1; color: var(--terra); font-weight: 300; margin-bottom: 0.7rem; }
.method h3 { font-size: 1.3125rem; margin-bottom: 0.4rem; }
.method p { font-size: 1.0625rem; color: var(--ink-2); margin: 0; }

/* ---------- Principle band ---------- */
.band { background: var(--band); color: var(--band-ink); padding-block: clamp(64px, 9vw, 112px); }
.band blockquote { margin: 0; max-width: 58rem; }
.band blockquote p { font-family: var(--f-display); font-style: italic; font-weight: 300; font-size: clamp(1.75rem, 3.6vw, 2.875rem); line-height: 1.16; margin: 0; }
.band .principles { list-style: none; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(20px, 3vw, 44px); margin-top: clamp(36px, 5vw, 56px); }
.band .principles li { border-top: 1px solid color-mix(in srgb, var(--band-ink) 30%, transparent); padding-top: 0.8rem; color: var(--band-muted); font-size: 1.0625rem; }
.band .principles strong { display: block; color: var(--band-ink); font-family: var(--f-display); font-weight: 500; font-size: 1.25rem; margin-bottom: 0.25rem; }

/* ---------- Platform teaser ---------- */
.platform { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: clamp(20px, 3vw, 40px); }
.product { background: var(--card); border: 1px solid var(--line-strong); padding: clamp(20px, 3vw, 34px); }
.product header { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-bottom: 0.7rem; }
.product h3 { font-size: 1.75rem; }
.product p { color: var(--ink-2); margin: 0; }
.product .tag { border-color: var(--ochre); }

/* ---------- Contact ---------- */
.contact-grid { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 6fr); gap: clamp(32px, 5vw, 72px); align-items: start; }
.contact-copy p { color: var(--ink-2); }
.contact-title { font-size: clamp(2rem, 4.2vw, 3.25rem); line-height: 1.04; letter-spacing: -0.015em; margin-bottom: 1.2rem; font-variation-settings: "opsz" 120; }
.contact-title em { font-style: italic; color: var(--terra); }
.contact-direct { border-top: 1px solid var(--line); padding-top: 1rem; }
.form { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px 20px; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field-full { grid-column: 1 / -1; }
.field label { font-weight: 700; font-size: 1rem; }
.field .hint { font-weight: 400; color: var(--muted); }
.field input, .field select, .field textarea {
  font: inherit; font-size: 1.0625rem; color: var(--ink); background: var(--card);
  border: 1.5px solid var(--line-strong); border-radius: 2px; padding: 0.65em 0.8em; min-height: 48px; width: 100%;
}
.field textarea { min-height: 150px; resize: vertical; }
.field input:focus-visible, .field select:focus-visible, .field textarea:focus-visible { outline: 3px solid var(--terra); outline-offset: 1px; border-color: var(--terra); }
.field [aria-invalid="true"] { border-color: #B3261E; }
.form-actions { grid-column: 1 / -1; display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.form-status { margin: 0; color: var(--ink-2); font-size: 1rem; }
.form-status.is-error { color: #B3261E; font-weight: 700; }
@media (prefers-color-scheme: dark) {
  .field [aria-invalid="true"] { border-color: #F2B8B5; }
  .form-status.is-error { color: #F2B8B5; }
}

/* ---------- Footer ---------- */
.site-footer { border-top: 3px double var(--line-strong); padding-block: 36px 48px; color: var(--muted); font-size: 1rem; }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px 32px; align-items: baseline; }
.footer-inner .wordmark { font-size: 1.375rem; color: var(--ink); }
.site-footer a { color: var(--ink-2); }

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .hero-grid, .section-head, .guide, .contact-grid { grid-template-columns: minmax(0, 1fr); }
  .services { grid-template-columns: minmax(0, 1fr); gap: 36px; }
  .service, .service:first-child { padding: 0; border-left: 0; border-top: 1px solid var(--line-strong); padding-top: 1.2rem; }
  .publics { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .method { grid-template-columns: minmax(0, 1fr); border-top: 0; }
  .method li, .method li + li { padding: 1.1rem 0; border-right: 0; border-top: 1px solid var(--line-strong); display: grid; grid-template-columns: 4rem 1fr; column-gap: 1rem; }
  .method li::before { grid-row: span 2; margin: 0; }
  .band .principles { grid-template-columns: minmax(0, 1fr); }
  .guide-tabs { flex-direction: row; flex-wrap: wrap; gap: 8px; border-top: 0; margin-bottom: 16px; }
  .guide-tab { border: 1px solid var(--line-strong); border-radius: 999px; padding: 0.45rem 0.9rem; font-size: 1.0625rem; }
  .guide-tab .q-num { display: none; }
  .guide-tab[aria-selected="true"] { background: var(--terra); color: var(--terra-ink); border-color: var(--terra); }
}
@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; align-items: center; }
  .site-nav {
    display: none; position: absolute; left: 0; right: 0; top: 100%;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--paper); border-bottom: 1px solid var(--line-strong);
    padding: 8px var(--gutter) 20px;
  }
  .site-nav.is-open { display: flex; }
  .site-nav a:not(.btn) { padding: 12px 0; border-bottom: 1px solid var(--line); }
  .site-nav .btn { margin-top: 14px; }
}
@media (max-width: 640px) {
  body { font-size: 1.125rem; }
  .publics, .platform, .form { grid-template-columns: minmax(0, 1fr); }
  .relief-frame { aspect-ratio: 5 / 2; }
  .guide-answer dl { grid-template-columns: minmax(0, 1fr); }
  .guide-answer dt { border-bottom: 0; padding-bottom: 0; }
  .baseline { font-size: 0.75rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}