/* ==========================================================================
   Oitavo — single stylesheet
   Tokens on :root, with a dark variant via prefers-color-scheme and [data-theme]
   ========================================================================== */

:root {
  color-scheme: light;

  --bg: #fbfaf7;
  --bg-card: #ffffff;
  --bg-soft: #f2efe9;
  --bg-code: #f5f2ec;

  --text: #1e1c19;
  --text-soft: #57534e;
  --text-faint: #8b857e;

  --border: #e5e0d8;
  --border-strong: #cfc8bd;

  --brand: #1f6f5c;
  --brand-light: #e3f0ec;
  --brand-strong: #175647;

  --accent: #b8531f;
  --accent-light: #fbeee5;

  --palette-indigo: #4a5fb8;   --palette-indigo-light: #e8eaf8;
  --palette-green: #1f6f5c;    --palette-green-light: #e3f0ec;
  --palette-orange: #b8531f;   --palette-orange-light: #fbeee5;
  --palette-purple: #6d46a3;   --palette-purple-light: #efe9f8;
  --palette-crimson: #a4324a;  --palette-crimson-light: #fae8ec;
  --palette-teal: #17697a;     --palette-teal-light: #e0f0f3;
  --palette-amber: #8a6413;    --palette-amber-light: #f8f0d9;
  --palette-slate: #4a5568;    --palette-slate-light: #eceef2;

  --radius: 10px;
  --radius-lg: 16px;
  --shadow: 0 1px 2px rgba(30, 28, 25, .04), 0 4px 16px rgba(30, 28, 25, .05);
  --shadow-lg: 0 2px 6px rgba(30, 28, 25, .06), 0 12px 32px rgba(30, 28, 25, .09);

  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;

  --width: 74rem;
  --width-text: 44rem;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;

    --bg: #16181a;
    --bg-card: #1e2124;
    --bg-soft: #24282c;
    --bg-code: #24282c;

    --text: #ecebe8;
    --text-soft: #b3b0aa;
    --text-faint: #83807b;

    --border: #32373b;
    --border-strong: #454b50;

    --brand: #63c4a9;
    --brand-light: #1b2f2a;
    --brand-strong: #7fd4bb;

    --accent: #e59462;
    --accent-light: #33241a;

    --palette-indigo: #8fa0ea;   --palette-indigo-light: #1e2340;
    --palette-green: #63c4a9;    --palette-green-light: #1b2f2a;
    --palette-orange: #e59462;   --palette-orange-light: #33241a;
    --palette-purple: #b092e0;   --palette-purple-light: #261c38;
    --palette-crimson: #e5808f;  --palette-crimson-light: #331a20;
    --palette-teal: #5fbccd;     --palette-teal-light: #122b31;
    --palette-amber: #d9b04e;    --palette-amber-light: #2e2611;
    --palette-slate: #9aa5b8;    --palette-slate-light: #22262e;

    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 4px 16px rgba(0, 0, 0, .25);
    --shadow-lg: 0 2px 6px rgba(0, 0, 0, .35), 0 12px 32px rgba(0, 0, 0, .4);
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;

  --bg: #16181a;
  --bg-card: #1e2124;
  --bg-soft: #24282c;
  --bg-code: #24282c;

  --text: #ecebe8;
  --text-soft: #b3b0aa;
  --text-faint: #83807b;

  --border: #32373b;
  --border-strong: #454b50;

  --brand: #63c4a9;
  --brand-light: #1b2f2a;
  --brand-strong: #7fd4bb;

  --accent: #e59462;
  --accent-light: #33241a;

  --palette-indigo: #8fa0ea;   --palette-indigo-light: #1e2340;
  --palette-green: #63c4a9;    --palette-green-light: #1b2f2a;
  --palette-orange: #e59462;   --palette-orange-light: #33241a;
  --palette-purple: #b092e0;   --palette-purple-light: #261c38;
  --palette-crimson: #e5808f;  --palette-crimson-light: #331a20;
  --palette-teal: #5fbccd;     --palette-teal-light: #122b31;
  --palette-amber: #d9b04e;    --palette-amber-light: #2e2611;
  --palette-slate: #9aa5b8;    --palette-slate-light: #22262e;

  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 4px 16px rgba(0, 0, 0, .25);
  --shadow-lg: 0 2px 6px rgba(0, 0, 0, .35), 0 12px 32px rgba(0, 0, 0, .4);
}

/* ----------------------------------------------------------------- base --- */

*, *::before, *::after { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--serif);
  line-height: 1.2;
  margin: 0;
  font-weight: 600;
  letter-spacing: -0.01em;
}

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--brand); text-underline-offset: 3px; }
a:hover { color: var(--brand-strong); }

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
  border-radius: 4px;
}

.wrap {
  max-width: var(--width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* --------------------------------------------------------------- header --- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(1.6) blur(12px);
  border-bottom: 1px solid var(--border);
}

.site-header-inner {
  max-width: var(--width);
  margin: 0 auto;
  padding: .75rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  display: flex;
  align-items: baseline;
  gap: .5rem;
}

.brand span {
  font-family: var(--sans);
  font-size: .7rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.site-header nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: .35rem;
}

.header-button {
  font: inherit;
  font-size: .85rem;
  background: none;
  border: 1px solid transparent;
  border-radius: 999px;
  padding: .35rem .8rem;
  color: var(--text-soft);
  cursor: pointer;
  text-decoration: none;
  transition: background .15s, color .15s, border-color .15s;
}

.header-button:hover {
  background: var(--bg-soft);
  color: var(--text);
}

.header-button[aria-pressed="true"] {
  background: var(--brand-light);
  border-color: color-mix(in srgb, var(--brand) 30%, transparent);
  color: var(--brand-strong);
  font-weight: 600;
}

/* ----------------------------------------------------------------- hero --- */

.hero {
  padding: 4.5rem 0 3rem;
  border-bottom: 1px solid var(--border);
}

.hero h1 {
  font-size: clamp(2.4rem, 6vw, 3.6rem);
  margin-bottom: .6rem;
}

.hero .lead {
  font-size: 1.15rem;
  color: var(--text-soft);
  max-width: var(--width-text);
}

.year-tag {
  display: inline-block;
  font-size: .74rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--brand);
  background: var(--brand-light);
  padding: .3rem .7rem;
  border-radius: 999px;
  margin-bottom: 1.1rem;
}

/* -------------------------------------------------------- subject cards --- */

.section { padding: 3rem 0; }

.section-header {
  display: flex;
  align-items: baseline;
  gap: .9rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.section-header h2 { font-size: 1.65rem; }

.section-header .section-count {
  font-size: .9rem;
  color: var(--text-faint);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(255px, 1fr));
  gap: 1rem;
}

.card {
  display: block;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.3rem;
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow);
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
  position: relative;
}

a.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-strong);
}

.card.disabled {
  opacity: .62;
  cursor: default;
  box-shadow: none;
}

.card .emoji { font-size: 1.7rem; line-height: 1; display: block; margin-bottom: .7rem; }
.card h3 { font-size: 1.15rem; margin-bottom: .35rem; }
.card p { font-size: .9rem; color: var(--text-soft); margin: 0; }

.badge {
  position: absolute;
  top: 1rem;
  right: 1rem;
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .05em;
  text-transform: uppercase;
  padding: .2rem .55rem;
  border-radius: 999px;
}

.badge.ready { background: var(--brand-light); color: var(--brand-strong); }
.badge.pending { background: var(--bg-soft); color: var(--text-faint); }

/* --------------------------------------------------------- subject page --- */

.subject-hero {
  padding: 3rem 0 2.2rem;
  border-bottom: 1px solid var(--border);
}

.breadcrumb {
  font-size: .85rem;
  color: var(--text-faint);
  margin-bottom: 1rem;
}

.breadcrumb a { color: var(--text-soft); }

.subject-hero h1 {
  font-size: clamp(2.1rem, 5vw, 3rem);
  display: flex;
  align-items: center;
  gap: .7rem;
  margin-bottom: .8rem;
}

.subject-hero .lead {
  max-width: var(--width-text);
  color: var(--text-soft);
  font-size: 1.05rem;
}

.domain-nav {
  display: flex;
  gap: .5rem;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.domain-link {
  font-size: .85rem;
  text-decoration: none;
  padding: .4rem .85rem;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  color: var(--text-soft);
  background: var(--bg-card);
  transition: background .15s, color .15s;
}

.domain-link:hover { background: var(--bg-soft); color: var(--text); }

/* Link to the DGE PDF. Sits in the hero, visible in every reading mode. */
.official-source { margin-top: 1.4rem; }

.official-source a {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-size: .9rem;
  color: var(--brand);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.official-source a:hover { color: var(--text); }

.file-type {
  font-size: .72rem;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--text-faint);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: .1rem .45rem;
  text-decoration: none;
}

/* --- domains --- */

.domain { padding: 3rem 0 1rem; scroll-margin-top: 5rem; }

.domain-header {
  display: flex;
  align-items: center;
  gap: .8rem;
  padding-bottom: .8rem;
  border-bottom: 2px solid var(--color, var(--brand));
  margin-bottom: .5rem;
}

.domain-header .emoji { font-size: 1.8rem; }
.domain-header h2 { font-size: 1.9rem; color: var(--color, var(--text)); }
.domain-header .domain-summary {
  margin-left: auto;
  font-size: .9rem;
  color: var(--text-faint);
  text-align: right;
  max-width: 28rem;
}

/* --- subtopics --- */

.subtopic {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  margin-top: 1.5rem;
  box-shadow: var(--shadow);
  scroll-margin-top: 5rem;
}

.subtopic > h3 {
  font-size: 1.4rem;
  margin-bottom: 1rem;
  color: var(--color, var(--text));
}

.student {
  max-width: var(--width-text);
  font-size: 1.02rem;
}

.questions {
  margin: 1.25rem 0 0;
  padding: 1rem 1.2rem;
  background: var(--bg-soft);
  border-radius: var(--radius);
  border-left: 3px solid var(--color, var(--brand));
}

.questions .label {
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--text-faint);
  display: block;
  margin-bottom: .5rem;
}

.questions ul { margin: 0; padding-left: 1.1rem; }
.questions li { margin-bottom: .3rem; font-style: italic; color: var(--text-soft); }
.questions li:last-child { margin-bottom: 0; }

/* --- official layer (details) --- */

details.official {
  margin-top: 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  overflow: hidden;
}

details.official > summary {
  cursor: pointer;
  padding: .8rem 1rem;
  font-size: .85rem;
  font-weight: 600;
  color: var(--text-soft);
  list-style: none;
  display: flex;
  align-items: center;
  gap: .55rem;
  user-select: none;
}

details.official > summary::-webkit-details-marker { display: none; }

details.official > summary::before {
  content: "▸";
  color: var(--text-faint);
  transition: transform .18s;
  display: inline-block;
}

details.official[open] > summary::before { transform: rotate(90deg); }
details.official > summary:hover { background: var(--bg-soft); color: var(--text); }

details.official .content {
  padding: .25rem 1rem 1.1rem 2.1rem;
  border-top: 1px solid var(--border);
}

details.official ol {
  margin: .9rem 0 0;
  padding-left: 1.2rem;
  font-size: .94rem;
  color: var(--text-soft);
}

details.official li { margin-bottom: .6rem; }

.source-note {
  font-size: .78rem;
  color: var(--text-faint);
  margin-top: .9rem;
  padding-top: .7rem;
  border-top: 1px dashed var(--border);
}

/* --- activities --- */

.activities-header {
  margin: 1.9rem 0 .9rem;
  font-size: .74rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--text-faint);
  display: flex;
  align-items: center;
  gap: .7rem;
}

.activities-header::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}

.activity {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: .8rem;
  background: var(--bg);
  overflow: hidden;
}

.activity > summary {
  cursor: pointer;
  padding: .95rem 1.1rem;
  list-style: none;
  display: flex;
  align-items: center;
  gap: .75rem;
  flex-wrap: wrap;
  user-select: none;
}

.activity > summary::-webkit-details-marker { display: none; }
.activity > summary:hover { background: var(--bg-soft); }

.activity .activity-title {
  font-family: var(--serif);
  font-size: 1.08rem;
  font-weight: 600;
  flex: 1;
  min-width: 12rem;
}

.pill {
  font-size: .7rem;
  font-weight: 600;
  padding: .22rem .6rem;
  border-radius: 999px;
  background: var(--color-light, var(--bg-soft));
  color: var(--color, var(--text-soft));
  white-space: nowrap;
}

.pill.duration {
  background: var(--bg-soft);
  color: var(--text-faint);
}

.activity .activity-body {
  padding: .3rem 1.1rem 1.3rem;
  border-top: 1px solid var(--border);
}

.activity h5 {
  font-family: var(--sans);
  font-size: .73rem;
  font-weight: 700;
  letter-spacing: .09em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin: 1.2rem 0 .5rem;
}

.activity ul.materials {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
}

.activity ul.materials li {
  font-size: .85rem;
  background: var(--bg-soft);
  border-radius: var(--radius);
  padding: .28rem .65rem;
  color: var(--text-soft);
}

.activity ol.steps {
  margin: 0;
  padding-left: 1.3rem;
  max-width: var(--width-text);
}

.activity ol.steps li { margin-bottom: .55rem; }

.note {
  margin-top: 1.2rem;
  padding: .85rem 1rem;
  border-radius: var(--radius);
  font-size: .9rem;
  display: flex;
  gap: .7rem;
  align-items: flex-start;
}

.note .icon { flex-shrink: 0; font-size: 1rem; line-height: 1.5; }
.note strong { display: block; font-size: .78rem; text-transform: uppercase; letter-spacing: .06em; margin-bottom: .15rem; }

.note.curriculum { background: var(--brand-light); color: var(--text); }
.note.curriculum strong { color: var(--brand-strong); }

.note.safety { background: var(--accent-light); color: var(--text); }
.note.safety strong { color: var(--accent); }

.note.reflection {
  background: var(--bg-soft);
  color: var(--text-soft);
  font-style: italic;
}
.note.reflection strong { color: var(--text-faint); font-style: normal; }

/* -------------------------------------------------------- reading modes --- */

/* Student mode hides the official layer and the curriculum notes. */
body[data-mode="student"] details.official,
body[data-mode="student"] .note.curriculum,
body[data-mode="student"] .matrix-note {
  display: none;
}

/* Curriculum mode shrinks the narrative layer and opens the official one. */
body[data-mode="curriculum"] .student { color: var(--text-soft); font-size: .95rem; }
body[data-mode="curriculum"] .questions { display: none; }

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

.site-footer {
  margin-top: 4rem;
  padding: 2.5rem 0 3.5rem;
  border-top: 1px solid var(--border);
  font-size: .87rem;
  color: var(--text-faint);
}

.site-footer p { max-width: var(--width-text); }
.site-footer a {
  color: var(--text-soft);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.site-footer a:hover { color: var(--text); }

/* --------------------------------------------------------------- status --- */

.status {
  padding: 4rem 1.5rem;
  text-align: center;
  color: var(--text-faint);
}

.status.error { color: var(--accent); }

.matrix-note {
  font-size: .85rem;
  color: var(--text-faint);
  background: var(--bg-soft);
  border-radius: var(--radius);
  padding: .9rem 1.1rem;
  margin-top: 1.5rem;
  max-width: var(--width-text);
}

/* ---------------------------------------------------------------- print --- */

@media print {
  .site-header, .domain-nav, .site-footer { display: none; }
  details.official, details.activity { border: none; }
  details.official > summary::before, .activity > summary { display: none; }
  .subtopic { box-shadow: none; break-inside: avoid; }
  body { font-size: 11pt; }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .wrap { padding: 0 1.1rem; }
  .site-header-inner { padding: .6rem 1.1rem; }
  .domain-header { flex-wrap: wrap; }
  .domain-header .domain-summary { margin-left: 0; text-align: left; width: 100%; }
  .subtopic { padding: 1.2rem; }
}