/* ==========================================================================
   @vectorspacepk — MATHS SITE
   BLUEPRINT visual system, "Daylight" edition.

   The Instagram brand is Ink-black. A teaching site is read for hours, so this
   version inverts it: Bone paper, Ink type, Acid as the single accent, with
   full-bleed Ink bands at the top and bottom of every page so it still reads
   unmistakably as the same brand.

   Layout: the Ink hero band is left-anchored to the page margin, poster-style.
   The content column below it is CENTRED in the window — text inside it still
   runs left, only the column is centred. See section 5.

   Everything on the site is styled from this one file. Change a value in
   :root below and it updates on all 42 pages at once.
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. BRAND TOKENS — the only place colours and fonts are defined
   -------------------------------------------------------------------------- */
:root {
  /* --- core palette (three brand colours, nothing else) --- */
  --ink:   #0E0F0D;   /* type, hero band, footer. Never pure black */
  --bone:  #F2F3EE;   /* the page. Never pure white */
  --acid:  #EFCC1D;   /* the one accent: eyebrows, numbers, rules, hovers */

  /* --- surfaces derived from Bone, not new colours --- */
  --paper:      #FAFAF7;  /* cards and panels: one step lighter than Bone */

  /* --- Acid, darkened, for small text on light backgrounds only.
         Pure Acid on Bone is unreadable at small sizes; this keeps the
         accent legible without introducing a second colour. --- */
  --acid-deep:  #7A6206;
  --acid-wash:  rgba(239,204,29,.18);  /* Acid at low strength: hover fills, callouts */

  /* --- hairlines and fills: Ink at low opacity, never grey --- */
  --line:       rgba(14,15,13,.14);   /* card borders, dividers */
  --line-soft:  rgba(14,15,13,.08);   /* table rows, inner rules */
  --grid:       rgba(14,15,13,.045);  /* the 56px technical grid on Bone */
  --grid-ink:   rgba(242,243,238,.06);/* the same grid inside the Ink band */

  /* --- text tiers: opacity steps, no grey tones --- */
  --text-body:   rgba(14,15,13,.78);
  --text-meta:   rgba(14,15,13,.58);
  --text-muted:  rgba(14,15,13,.45);
  --on-ink-body: rgba(242,243,238,.74);
  --on-ink-meta: rgba(242,243,238,.52);

  /* --- typefaces --- */
  --font-sans: 'Space Grotesk', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;

  /* --- layout --- */
  --margin: clamp(20px, 5.5vw, 88px);  /* the margin nothing crosses */
  --wide: 1240px;                       /* content measure */
  --shadow: 6px 6px 0 rgba(14,15,13,.07); /* hard offset. No blur, no glow */
}

/* --------------------------------------------------------------------------
   2. RESET & BASE
   -------------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; border-radius: 0; }

html { scroll-behavior: smooth; }

body {
  background-color: var(--bone);
  color: var(--ink);
  font-family: var(--font-sans);
  font-weight: 400;
  line-height: 1.55;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  /* the technical grid: two 1px lines crossing every 56px */
  background-image:
    linear-gradient(to right, var(--grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px);
  background-size: 56px 56px;
  display: flex;
  flex-direction: column;
}

a { color: inherit; }
img { max-width: 100%; display: block; }

/* keyboard users always see where they are */
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--acid-deep);
  outline-offset: 3px;
}

/* skip link for screen-reader and keyboard users */
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--ink); color: var(--bone);
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .12em;
  text-transform: uppercase; padding: .9rem 1.2rem; text-decoration: none;
}
.skip-link:focus { left: 0; }

/* --------------------------------------------------------------------------
   3. TOP NAV — sticky, identical on every page
   -------------------------------------------------------------------------- */
nav.sitebar {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem 2rem; flex-wrap: wrap;
  padding: .95rem var(--margin);
  background: rgba(242,243,238,.88);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}

/* the handle, always set in mono, with a small Acid mark before it */
nav.sitebar .brand {
  display: inline-flex; align-items: center; gap: .6rem;
  font-family: var(--font-mono); font-size: .88rem; font-weight: 500;
  letter-spacing: .01em; text-decoration: none; color: var(--ink);
}
nav.sitebar .brand::before {
  content: ""; width: 13px; height: 13px;
  background: var(--acid); border: 1px solid var(--ink);
  transition: transform .18s ease;
}
nav.sitebar .brand:hover::before { transform: rotate(45deg); }

nav.sitebar .links { display: flex; align-items: center; gap: clamp(.9rem, 2.4vw, 2rem); flex-wrap: wrap; }
nav.sitebar .links a {
  position: relative;
  text-decoration: none; color: var(--text-meta);
  font-family: var(--font-mono); font-weight: 500;
  text-transform: uppercase; letter-spacing: .14em; font-size: .68rem;
  padding: .45rem 0;
  transition: color .14s;
}
nav.sitebar .links a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -.1rem;
  height: 5px; background: var(--acid);
  transform: scaleX(0); transform-origin: left; transition: transform .18s ease;
}
nav.sitebar .links a:hover { color: var(--ink); }
nav.sitebar .links a:hover::after { transform: scaleX(1); }
nav.sitebar .links a.active { color: var(--ink); }
nav.sitebar .links a.active::after { transform: scaleX(1); }

/* --------------------------------------------------------------------------
   4. HERO — the full-bleed Ink band at the top of every page
   -------------------------------------------------------------------------- */
header.hero {
  position: relative; overflow: hidden;
  background-color: var(--ink);
  color: var(--bone);
  padding: clamp(3rem, 7vw, 5.4rem) var(--margin) clamp(2.6rem, 6vw, 4.4rem);
  /* the grid again, this time in Bone over Ink — same system, inverted */
  background-image:
    linear-gradient(to right, var(--grid-ink) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-ink) 1px, transparent 1px);
  background-size: 56px 56px;
  border-bottom: 3px solid var(--acid);  /* the Acid rule that closes the band */
}
header.hero > * { position: relative; z-index: 2; }

/* faint maths behind the headline — decorative, mono, never a real statement */
.hero-formulas {
  position: absolute; inset: 0; z-index: 1; pointer-events: none;
  font-family: var(--font-mono); color: var(--bone); opacity: .085;
  user-select: none;
}
.hero-formulas span { position: absolute; font-size: clamp(.95rem, 1.6vw, 1.45rem); white-space: nowrap; }

/* every page opens with an Acid eyebrow */
.eyebrow {
  display: inline-flex; align-items: center; gap: .6rem;
  font-family: var(--font-mono); font-weight: 500;
  letter-spacing: .24em; text-transform: uppercase; font-size: .68rem;
  color: var(--acid); margin-bottom: 1.4rem;
}
.eyebrow::before { content: ""; width: 22px; height: 1px; background: var(--acid); }

/* DISPLAY type: uppercase, tight leading, negative tracking */
h1.title {
  font-family: var(--font-sans); font-weight: 700; text-transform: uppercase;
  font-size: clamp(2.1rem, 5.6vw, 4.2rem);
  line-height: .98; letter-spacing: -.035em;
  max-width: 22ch; text-wrap: balance;
}
.hero-sub {
  margin-top: 1.5rem; max-width: 56ch;
  color: var(--on-ink-body); font-size: clamp(.98rem, 1.3vw, 1.08rem); line-height: 1.6;
}

/* a row of small mono facts under the hero copy — quiet reassurance */
.hero-meta {
  display: flex; flex-wrap: wrap; gap: .5rem .75rem; margin-top: 2.2rem;
}
.hero-meta span {
  font-family: var(--font-mono); font-size: .66rem; font-weight: 500;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--acid);
  border: 1px solid rgba(239,204,29,.45); padding: .48rem .7rem;
}
/* the first chip is filled — one Acid-background element, per the guide */
.hero-meta span:first-child { background: var(--acid); color: var(--ink); border-color: var(--acid); font-weight: 700; }

/* --------------------------------------------------------------------------
   5. MAIN CONTENT — always aligned left to the margin, never centred
   -------------------------------------------------------------------------- */
main {
  flex: 1 0 auto;
  width: 100%; max-width: var(--wide);
  /* the content column is CENTRED in the window. Text inside it still runs
     left — only the column itself is centred. The Ink hero band above is
     deliberately left-anchored to the margin, poster-style. */
  margin: 0 auto;
  padding: clamp(2.4rem, 5vw, 4rem) var(--margin) clamp(4rem, 8vw, 6.5rem);
}

/* a small mono label used to head a block of content */
.block-label {
  display: flex; align-items: center; gap: .8rem;
  font-family: var(--font-mono); font-size: .66rem; font-weight: 600;
  letter-spacing: .22em; text-transform: uppercase; color: var(--ink);
  margin-bottom: 1.4rem;
}
.block-label::before { content: ""; width: 12px; height: 12px; background: var(--acid); border: 1px solid var(--ink); flex: none; }
.block-label::after { content: ""; flex: 1; height: 3px; background: var(--acid); }

/* an Acid highlight behind a word or two — the brand's "put the answer in Acid" */
.hl { background: var(--acid); color: var(--ink); padding: 0 .18em; box-decoration-break: clone; -webkit-box-decoration-break: clone; }

/* --------------------------------------------------------------------------
   6. WELCOME PAGE — the two big course cards
   -------------------------------------------------------------------------- */
.subject-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(310px, 1fr));
  gap: clamp(1rem, 2vw, 1.6rem);
}
.subject-card {
  position: relative; display: flex; flex-direction: column; overflow: hidden;
  background: var(--paper); border: 1px solid var(--line);
  padding: clamp(1.8rem, 3vw, 2.6rem);
  text-decoration: none; color: var(--ink);
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
/* the Acid bar that fills in from the left on hover */
.subject-card::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 5px;
  background: var(--acid); transform: scaleY(0); transform-origin: top;
  transition: transform .22s ease;
}
/* a large decorative glyph, taken from data-glyph="" in the HTML */
.subject-card::after {
  content: attr(data-glyph);
  position: absolute; right: -.1em; bottom: -.45em;
  font-family: var(--font-mono); font-size: 11rem; line-height: 1;
  color: var(--ink); opacity: .045; pointer-events: none;
}
/* on hover the whole card fills with Acid — the loudest moment on the page */
.subject-card:hover {
  transform: translateY(-3px); box-shadow: var(--shadow);
  background: var(--acid); border-color: var(--ink);
}
.subject-card:hover::before { transform: scaleY(1); background: var(--ink); }
.subject-card:hover::after { opacity: .11; }
.subject-card:hover .subject-desc { color: rgba(14,15,13,.8); }
.subject-card:hover .subject-tag { background: var(--ink); color: var(--acid); border-color: var(--ink); }

.subject-tag {
  font-family: var(--font-mono); font-size: .64rem; font-weight: 600;
  color: var(--ink); text-transform: uppercase; letter-spacing: .2em;
  background: var(--acid); border: 1px solid var(--ink);
  padding: .35rem .6rem; align-self: flex-start;
  transition: background-color .18s, color .18s;
}
.subject-title {
  font-family: var(--font-sans); font-size: clamp(1.45rem, 2.6vw, 1.95rem);
  font-weight: 700; line-height: 1.02; letter-spacing: -.03em;
  text-transform: uppercase; margin: 1.3rem 0 .8rem; max-width: 18ch;
}
.subject-desc { color: var(--text-body); font-size: .95rem; max-width: 44ch; }
/* the "Open the course →" line at the foot of each card */
.subject-go {
  margin-top: 1.8rem; font-family: var(--font-mono); font-size: .7rem;
  font-weight: 500; letter-spacing: .14em; text-transform: uppercase; color: var(--ink);
  display: inline-flex; align-items: center; gap: .5rem;
}
.subject-go::after { content: "→"; transition: transform .18s ease; }
.subject-card:hover .subject-go::after { transform: translateX(5px); }

/* --- "how it works" — three numbered steps, plain and reassuring --- */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: clamp(1rem, 2.6vw, 2.2rem); }
.step { background: transparent; border-top: 4px solid var(--acid); padding: 1.1rem 0 0; }
.step-num {
  font-family: var(--font-mono); font-size: .7rem; font-weight: 700;
  letter-spacing: .16em; color: var(--ink); background: var(--acid);
  border: 1px solid var(--ink); padding: .28rem .5rem;
  display: inline-block; margin-bottom: .8rem;
}
.step-title { font-family: var(--font-sans); font-weight: 600; font-size: 1.02rem; margin-bottom: .35rem; }
.step-text { color: var(--text-meta); font-size: .88rem; max-width: 34ch; }

/* --------------------------------------------------------------------------
   7. SUBJECT PAGES — the chapter grid
   -------------------------------------------------------------------------- */
.chapter-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(258px, 1fr));
  gap: clamp(.7rem, 1.4vw, 1rem);
}
.chapter-card {
  position: relative; display: flex; flex-direction: column; gap: .9rem;
  background: var(--paper); border: 1px solid var(--line);
  padding: 1.35rem 1.4rem 1.5rem;
  text-decoration: none; color: var(--ink);
  transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease;
}
.chapter-card:hover {
  transform: translateY(-2px); box-shadow: var(--shadow);
  border-color: var(--ink); background: var(--acid-wash);
}
/* the two-digit counter, always mono, in a solid Acid chip */
.chapter-num {
  align-self: flex-start;
  font-family: var(--font-mono); font-size: .68rem; font-weight: 700; letter-spacing: .1em;
  color: var(--ink); background: var(--acid);
  border: 1px solid var(--ink); padding: .3rem .5rem;
  transition: background-color .16s ease, color .16s ease;
}
.chapter-card:hover .chapter-num { background: var(--ink); color: var(--acid); }
.chapter-name {
  font-family: var(--font-sans); font-size: 1.02rem; font-weight: 600;
  line-height: 1.25; letter-spacing: -.012em;
  padding-right: 1.8rem;  /* leaves room for the hover arrow */
}
/* the arrow that slides in on hover */
.chapter-card::after {
  content: "→"; position: absolute; right: 1.4rem; bottom: 1.35rem;
  font-family: var(--font-mono); color: var(--ink); font-weight: 700;
  opacity: 0; transform: translateX(-6px); transition: opacity .16s ease, transform .16s ease;
}
.chapter-card:hover::after { opacity: 1; transform: translateX(0); }

/* --------------------------------------------------------------------------
   8. FURTHER MATH — chapters grouped under each of the four papers
   -------------------------------------------------------------------------- */
.paper-section { margin-top: clamp(3rem, 5vw, 4.2rem); }
.paper-section:first-of-type { margin-top: 0; }
.paper-head {
  display: flex; align-items: baseline; gap: 1.2rem; flex-wrap: wrap;
  margin-bottom: .5rem; padding-top: clamp(1.8rem, 3vw, 2.4rem);
  border-top: 5px solid var(--acid);
}
.paper-num {
  font-family: var(--font-mono); font-size: .66rem; font-weight: 700;
  letter-spacing: .2em; text-transform: uppercase;
  color: var(--ink); background: var(--acid);
  padding: .34rem .6rem; border: 1px solid var(--ink);
}
h2.paper-title {
  font-family: var(--font-sans); font-size: clamp(1.3rem, 2.4vw, 1.8rem);
  font-weight: 700; line-height: 1.08; letter-spacing: -.025em;
}
.paper-desc {
  color: var(--text-meta); font-size: .92rem;
  margin-bottom: 1.5rem; max-width: 62ch;
}

/* --------------------------------------------------------------------------
   9. CHAPTER PAGES — breadcrumb, section headings, resources
   -------------------------------------------------------------------------- */
/* the breadcrumb sits inside the Ink hero band, above the chapter title */
.crumb {
  font-family: var(--font-mono); font-size: .68rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--on-ink-meta); margin-bottom: 1.2rem;
}
.crumb a { color: var(--acid); text-decoration: none; border-bottom: 1px solid transparent; }
.crumb a:hover { border-color: var(--acid); }
.crumb .sep { color: rgba(242,243,238,.3); margin: 0 .5rem; }

h2.section-title {
  font-family: var(--font-sans); font-size: clamp(1.15rem, 2vw, 1.4rem);
  font-weight: 700; line-height: 1.15; letter-spacing: -.02em;
  margin: clamp(2.6rem, 4.5vw, 3.6rem) 0 1.4rem;
  padding-top: clamp(1.6rem, 3vw, 2.2rem);
  border-top: 5px solid var(--acid);
  display: flex; align-items: baseline; gap: .8rem;
}
/* the very first heading on a page needs no divider — the Acid hero rule is above it */
main > h2.section-title:first-child { margin-top: 0; padding-top: 0; border-top: none; }
main > h2.section-title:first-of-type { margin-top: 0; }
/* the small mono counter that can be placed inside a section title */
h2.section-title .count {
  font-family: var(--font-mono); font-size: .64rem; font-weight: 500;
  letter-spacing: .16em; color: var(--text-muted); text-transform: uppercase;
}

/* --- embedded YouTube players --- */
.video-block { margin-bottom: clamp(1.8rem, 3vw, 2.4rem); max-width: 760px; }
.video-label {
  display: flex; align-items: center; gap: .6rem;
  font-family: var(--font-mono); font-size: .68rem; font-weight: 500;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--text-meta); margin-bottom: .75rem;
}
.video-label::before { content: ""; width: 8px; height: 8px; background: var(--acid); border: 1px solid var(--ink); flex: none; }
.video-wrap {
  position: relative; width: 100%; aspect-ratio: 16/9;
  background: var(--ink); border: 1px solid var(--line);
  box-shadow: var(--shadow); overflow: hidden;
}
.video-wrap iframe { width: 100%; height: 100%; border: 0; display: block; }

/* --- notes: each downloadable file is a full-width row --- */
.notes-list { list-style: none; display: grid; gap: .6rem; max-width: 760px; }
.notes-list li { margin: 0; }
.resource-link {
  color: var(--ink); text-decoration: none;
  font-size: .95rem; font-weight: 500;
  display: inline-flex; align-items: center; gap: .55rem;
  border-bottom: 1px solid var(--line); padding-bottom: 2px;
  transition: color .14s, border-color .14s;
}
.resource-link:hover { color: var(--acid-deep); border-color: var(--acid); }
/* inside a notes list the link becomes a bordered row with a PDF chip */
.notes-list .resource-link {
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  background: var(--paper); border: 1px solid var(--line);
  border-left: 5px solid var(--acid);   /* every downloadable file carries an Acid spine */
  padding: 1rem 1.2rem; transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease, background-color .16s ease;
}
.notes-list .resource-link::after {
  content: "View PDF"; font-family: var(--font-mono); font-size: .64rem; font-weight: 600;
  letter-spacing: .14em; color: var(--ink);
  background: var(--acid); border: 1px solid var(--ink);
  padding: .3rem .5rem; flex: none;
}
.notes-list .resource-link:hover {
  transform: translateY(-2px); box-shadow: var(--shadow);
  border-color: var(--ink); border-left-color: var(--acid);
  background: var(--acid-wash); color: var(--ink);
}
.notes-list .resource-link:hover::after { background: var(--ink); color: var(--acid); }

/* --- past papers table --- */
.table-wrap { max-width: 980px; border: 1px solid var(--ink); background: var(--paper); }
table.papers { width: 100%; border-collapse: collapse; font-size: .92rem; }
/* the header row is a solid Acid band with Ink type */
table.papers th {
  text-align: left; font-family: var(--font-mono); text-transform: uppercase;
  letter-spacing: .16em; font-size: .62rem; font-weight: 700; color: var(--ink);
  padding: .85rem 1rem; border-bottom: 1px solid var(--ink);
  background: var(--acid);
  white-space: nowrap;
}
table.papers td {
  padding: .95rem 1rem; border-bottom: 1px solid var(--line-soft); vertical-align: middle;
}
table.papers tbody tr:last-child td { border-bottom: none; }
table.papers tbody tr { transition: background-color .14s; }
table.papers tbody tr:hover { background: var(--acid-wash); }
/* years are numbers, so they are set in mono */
table.papers td:first-child { font-family: var(--font-mono); font-weight: 700; white-space: nowrap; }
.tag {
  display: inline-block; font-family: var(--font-mono); font-size: .6rem;
  font-weight: 600; letter-spacing: .12em; text-transform: uppercase;
  padding: .24rem .45rem; margin-left: .4rem;
  background: var(--acid); color: var(--ink);
  border: 1px solid var(--ink);
}

/* --------------------------------------------------------------------------
   10. ABOUT BLOCK on the welcome page
   -------------------------------------------------------------------------- */
/* the "how to use this site" strip — its Acid rule comes from .block-label */
.howto { margin-top: clamp(3rem, 6vw, 4.8rem); }

.about-section {
  margin-top: clamp(3rem, 6vw, 4.8rem); padding-top: clamp(2rem, 4vw, 3rem);
  border-top: 5px solid var(--acid);
  display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  gap: clamp(1.6rem, 4vw, 3.4rem); align-items: start;
}
.about-section h2 {
  font-family: var(--font-sans); font-size: clamp(1.5rem, 2.8vw, 2rem); font-weight: 700;
  text-transform: uppercase; letter-spacing: -.03em; line-height: 1.02; margin-bottom: 1.3rem;
}
.about-section p {
  color: var(--text-body); margin-bottom: 1.05rem; font-size: 1rem; line-height: 1.65; max-width: 62ch;
}
.about-section p:last-child { margin-bottom: 0; }
/* the side panel: what a student gets in every chapter */
.about-aside { background: var(--ink); color: var(--bone); padding: 1.8rem; border-top: 5px solid var(--acid); }
.about-aside h3 {
  font-family: var(--font-mono); font-size: .66rem; font-weight: 500;
  letter-spacing: .22em; text-transform: uppercase; color: var(--acid); margin-bottom: 1.2rem;
}
.about-aside ul { list-style: none; }
.about-aside li {
  display: flex; gap: .8rem; padding: .7rem 0;
  border-top: 1px solid rgba(242,243,238,.16);
  font-size: .92rem; color: var(--on-ink-body);
}
.about-aside li:first-of-type { border-top: none; padding-top: 0; }
.about-aside li strong { color: var(--bone); font-weight: 600; }
.about-aside li::before {
  content: "→"; font-family: var(--font-mono); color: var(--acid); flex: none;
}

/* --------------------------------------------------------------------------
   11. CONTACT PAGE
   -------------------------------------------------------------------------- */
.contact-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: clamp(.8rem, 1.6vw, 1.2rem); margin-bottom: clamp(2.6rem, 5vw, 4rem);
}
.contact-card {
  position: relative; overflow: hidden;
  background: var(--paper); border: 1px solid var(--line); padding: 1.8rem;
  text-decoration: none; display: block; color: var(--ink);
  transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease;
}
.contact-card::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 5px;
  background: var(--acid); transform: scaleY(0); transform-origin: top; transition: transform .22s ease;
}
.contact-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--ink); background: var(--acid); }
.contact-card:hover::before { transform: scaleY(1); background: var(--ink); }
.contact-card:hover .contact-icon { background: var(--ink); color: var(--acid); }
.contact-card:hover .contact-detail { color: rgba(14,15,13,.72); }
.contact-card .contact-icon {
  display: inline-block;
  font-family: var(--font-mono); font-size: .64rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: .2em; color: var(--ink);
  background: var(--acid); border: 1px solid var(--ink); padding: .32rem .55rem;
  transition: background-color .18s, color .18s;
}
.contact-card .contact-title {
  font-family: var(--font-sans); font-size: 1.2rem; font-weight: 700;
  letter-spacing: -.02em; margin: 1.1rem 0 .45rem;
}
.contact-card .contact-detail {
  color: var(--text-meta); font-size: .84rem; font-family: var(--font-mono); word-break: break-word;
}

form.contact-form { max-width: 620px; background: var(--paper); border: 1px solid var(--line); padding: clamp(1.4rem, 3vw, 2.2rem); }
form.contact-form label {
  display: block; font-family: var(--font-mono); font-size: .66rem; font-weight: 500;
  text-transform: uppercase; letter-spacing: .16em; color: var(--text-muted);
  margin: 1.6rem 0 .55rem;
}
form.contact-form label:first-child { margin-top: 0; }
form.contact-form input, form.contact-form textarea {
  width: 100%; background: var(--bone); border: 1px solid var(--line);
  padding: .85rem 1rem; color: var(--ink); font-family: var(--font-sans); font-size: .96rem;
  transition: border-color .14s, box-shadow .14s;
}
form.contact-form input:focus, form.contact-form textarea:focus {
  outline: none; border-color: var(--ink); box-shadow: inset 0 -3px 0 var(--acid);
}
form.contact-form textarea { resize: vertical; min-height: 140px; }
/* the one Acid-filled element on the page: Ink text on Acid */
form.contact-form button {
  margin-top: 2rem; background: var(--acid); color: var(--ink);
  border: 1px solid var(--ink);
  font-family: var(--font-mono); font-weight: 700; text-transform: uppercase;
  letter-spacing: .16em; font-size: .7rem; padding: 1rem 2.1rem; cursor: pointer;
  display: inline-flex; align-items: center; gap: .6rem;
  transition: background-color .16s, color .16s, transform .16s, box-shadow .16s;
}
form.contact-form button::after { content: "→"; }
form.contact-form button:hover {
  background: var(--ink); color: var(--acid);
  transform: translateY(-2px); box-shadow: var(--shadow);
}
.form-note {
  color: var(--text-body); font-size: .84rem; margin-top: 1.3rem; max-width: 58ch;
  background: var(--acid-wash); border-left: 5px solid var(--acid);
  padding: .9rem 1rem;
}

/* --------------------------------------------------------------------------
   12. FOOTER — the Ink band that closes every page
   -------------------------------------------------------------------------- */
footer {
  background: var(--ink); color: var(--on-ink-meta);
  border-top: 3px solid var(--acid);
  padding: clamp(2rem, 4vw, 2.8rem) var(--margin);
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .05em;
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 1rem 2rem;
}
footer a { color: var(--acid); text-decoration: none; border-bottom: 1px solid transparent; }
footer a:hover { border-color: var(--acid); }
footer .handle { color: var(--on-ink-body); }

/* --------------------------------------------------------------------------
   13. RESPONSIVE
   -------------------------------------------------------------------------- */
@media (max-width: 860px) {
  .about-section { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  body { background-size: 40px 40px; }
  header.hero { background-size: 40px 40px; }
  .hero-formulas { display: none; }   /* keep small screens clean */
  .subject-card::after { font-size: 7rem; }
  nav.sitebar { padding: .8rem var(--margin); }
  nav.sitebar .links { gap: .9rem; }

  /* the past-papers table becomes a stacked list */
  .table-wrap { border: none; background: transparent; }
  table.papers, table.papers thead, table.papers tbody,
  table.papers th, table.papers td, table.papers tr { display: block; }
  table.papers thead { display: none; }
  table.papers tbody tr {
    background: var(--paper); border: 1px solid var(--line);
    padding: 1rem 1.1rem; margin-bottom: .7rem;
  }
  table.papers tbody tr:hover { background: var(--paper); }
  table.papers td { border: none; padding: .3rem 0; }
  table.papers td:first-child { font-size: 1rem; margin-bottom: .5rem; }
  /* label each stacked cell so it still makes sense without column headers */
  table.papers td[data-label]::before {
    content: attr(data-label);
    display: block; font-family: var(--font-mono); font-size: .58rem;
    letter-spacing: .16em; text-transform: uppercase; color: var(--text-muted);
    margin-bottom: .2rem;
  }
}

/* --------------------------------------------------------------------------
   14. MOTION & PRINT
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}

@media print {
  body { background: #fff; }
  nav.sitebar, .hero-formulas, footer { display: none; }
  header.hero { background: #fff; color: #000; border-bottom: 2px solid #000; }
  h1.title, .hero-sub, .crumb, .crumb a { color: #000; }
  .video-wrap { display: none; }
}

/* ==========================================================================
   15. COMPONENTS ADDED FOR VECTORSPACE.PK
   Everything below uses the same three brand colours and the same rules:
   square corners, flat colour, left aligned, hard offset shadows only.
   ========================================================================== */

/* --- inline links inside body copy --- */
.inline-link { color: var(--ink); text-decoration: none; box-shadow: inset 0 -6px 0 var(--acid-wash); transition: box-shadow .15s; }
.inline-link:hover { box-shadow: inset 0 -1.1em 0 var(--acid); }

/* --- the opening paragraphs of a topic or page --- */
.topic-intro { max-width: 66ch; margin-bottom: 2.4rem; }
.topic-intro p { color: var(--text-body); font-size: 1.05rem; line-height: 1.65; margin-bottom: 1rem; }
.topic-intro p:last-child { margin-bottom: 0; }

.about-prose { max-width: 68ch; }
.about-prose p { color: var(--text-body); font-size: 1.02rem; line-height: 1.68; margin-bottom: 1.1rem; }
.about-prose h3 { font-family: var(--font-sans); font-size: 1.1rem; font-weight: 700; margin: 2rem 0 .8rem; }
.prose-list { list-style: none; margin: 0 0 1.2rem; }
.prose-list li { position: relative; padding-left: 1.4rem; margin-bottom: .55rem; color: var(--text-body); }
.prose-list li::before { content: "—"; position: absolute; left: 0; color: var(--acid-deep); }

/* --- syllabus points --- */
.syllabus-list { list-style: none; max-width: 74ch; margin-bottom: 1rem; border-left: 5px solid var(--acid); padding-left: 1.2rem; }
.syllabus-list li { position: relative; padding: .5rem 0; color: var(--text-body); font-size: .96rem; border-bottom: 1px solid var(--line-soft); }
.syllabus-list li:last-child { border-bottom: none; }

/* --- click-to-load video: a thumbnail until the student taps it --- */
.video-facade {
  width: 100%; height: 100%; border: 0; padding: 0; cursor: pointer; display: block;
  background-size: cover; background-position: center; position: relative;
}
.video-facade::after { content: ""; position: absolute; inset: 0; background: rgba(14,15,13,.34); transition: background-color .16s; }
.video-facade:hover::after { background: rgba(14,15,13,.16); }
.video-play {
  position: absolute; z-index: 2; left: 50%; top: 50%; transform: translate(-50%,-50%);
  width: 66px; height: 46px; background: var(--acid); color: var(--ink);
  border: 2px solid var(--ink); display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem; transition: transform .16s;
}
.video-facade:hover .video-play { transform: translate(-50%,-50%) scale(1.08); }
.video-wrap.is-playing { box-shadow: none; }
.video-pending {
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .16em;
  text-transform: uppercase; color: var(--on-ink-meta); box-shadow: none;
}

/* --- common mistakes: numbered, in mono, because they're a checklist --- */
.mistakes-list { list-style: none; counter-reset: m; max-width: 74ch; }
.mistakes-list li {
  counter-increment: m; position: relative; padding: 1rem 1.2rem 1rem 3.4rem;
  background: var(--paper); border: 1px solid var(--line); border-left: 5px solid var(--acid);
  margin-bottom: .6rem; color: var(--text-body); font-size: .96rem;
}
.mistakes-list li::before {
  content: counter(m, decimal-leading-zero); position: absolute; left: 1.1rem; top: 1rem;
  font-family: var(--font-mono); font-size: .72rem; font-weight: 700; color: var(--acid-deep);
}
.tips-list { list-style: none; max-width: 74ch; }
.tips-list li { position: relative; padding: .6rem 0 .6rem 1.8rem; color: var(--text-body); font-size: .96rem; border-bottom: 1px solid var(--line-soft); }
.tips-list li::before { content: "→"; position: absolute; left: 0; color: var(--acid-deep); font-family: var(--font-mono); }
.tips-list li:last-child { border-bottom: none; }

/* --- FAQs: native accordions, no JavaScript needed --- */
.faq { border: 1px solid var(--line); background: var(--paper); margin-bottom: .6rem; max-width: 74ch; }
.faq summary {
  cursor: pointer; padding: 1rem 1.2rem; font-weight: 600; font-size: .98rem;
  list-style: none; display: flex; justify-content: space-between; gap: 1rem; align-items: center;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-family: var(--font-mono); color: var(--acid-deep); font-size: 1.2rem; flex: none; }
.faq[open] summary::after { content: "−"; }
.faq[open] summary { border-bottom: 1px solid var(--line); background: var(--acid-wash); }
.faq-a { padding: 1rem 1.2rem; color: var(--text-body); font-size: .95rem; line-height: 1.6; }

/* --- byline at the foot of a topic page --- */
.byline {
  margin-top: 3rem; padding-top: 1.2rem; border-top: 1px solid var(--line);
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .04em; color: var(--text-meta);
}
.byline a { color: var(--ink); }

/* --- courses --- */
.course-card { background: var(--paper); border: 1px solid var(--line); border-top: 5px solid var(--acid); padding: 1.6rem; margin-bottom: 1rem; max-width: 780px; }
.course-past { border-top-color: var(--line); opacity: .72; }
.course-badge {
  display: inline-block; font-family: var(--font-mono); font-size: .62rem; font-weight: 700;
  letter-spacing: .16em; text-transform: uppercase; background: var(--acid); color: var(--ink);
  border: 1px solid var(--ink); padding: .3rem .55rem;
}
.course-name { font-family: var(--font-sans); font-size: 1.3rem; font-weight: 700; letter-spacing: -.02em; margin: 1rem 0 .5rem; }
.course-summary { color: var(--text-body); font-size: .96rem; max-width: 62ch; margin-bottom: 1.2rem; }
.course-fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: .9rem 1.4rem; margin-bottom: 1.4rem; }
.course-field dt { font-family: var(--font-mono); font-size: .6rem; letter-spacing: .16em; text-transform: uppercase; color: var(--text-muted); margin-bottom: .25rem; }
.course-field dd { font-size: .92rem; font-weight: 500; }
.course-cta {
  display: inline-flex; align-items: center; gap: .5rem; background: var(--acid); color: var(--ink);
  border: 1px solid var(--ink); font-family: var(--font-mono); font-weight: 700;
  text-transform: uppercase; letter-spacing: .14em; font-size: .68rem;
  padding: .85rem 1.5rem; text-decoration: none; transition: background-color .16s, color .16s, transform .16s, box-shadow .16s;
}
.course-cta::after { content: "→"; }
.course-cta:hover { background: var(--ink); color: var(--acid); transform: translateY(-2px); box-shadow: var(--shadow); }

/* the "next course" band on the home page */
.course-strip {
  display: flex; align-items: center; justify-content: space-between; gap: 1.6rem; flex-wrap: wrap;
  background: var(--ink); color: var(--bone); border-top: 5px solid var(--acid);
  padding: 1.8rem; margin-top: clamp(3rem, 6vw, 4.8rem);
}
.course-strip p { color: var(--on-ink-body); font-size: .92rem; max-width: 52ch; margin-top: .5rem; }
.course-strip-name { font-family: var(--font-sans); font-size: 1.4rem; font-weight: 700; letter-spacing: -.02em; margin-top: .9rem; }

form.contact-form select {
  width: 100%; background: var(--bone); border: 1px solid var(--line);
  padding: .85rem 1rem; color: var(--ink); font-family: var(--font-sans); font-size: .96rem;
}
form.contact-form select:focus { outline: none; border-color: var(--ink); box-shadow: inset 0 -3px 0 var(--acid); }

/* --- resources filter --- */
.filters { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 1.6rem; align-items: center; }
.filters input[type="search"] {
  flex: 1 1 240px; background: var(--paper); border: 1px solid var(--line);
  padding: .75rem 1rem; font-family: var(--font-sans); font-size: .94rem; color: var(--ink);
}
.filters input[type="search"]:focus { outline: none; border-color: var(--ink); box-shadow: inset 0 -3px 0 var(--acid); }
.chip {
  font-family: var(--font-mono); font-size: .64rem; font-weight: 500; letter-spacing: .12em;
  text-transform: uppercase; padding: .55rem .7rem; cursor: pointer;
  background: var(--paper); color: var(--text-meta); border: 1px solid var(--line);
  transition: background-color .14s, color .14s, border-color .14s;
}
.chip:hover { border-color: var(--ink); color: var(--ink); }
.chip.is-on { background: var(--acid); color: var(--ink); border-color: var(--ink); font-weight: 700; }

/* --- small bits --- */
.soon-row { margin-top: 1.6rem; font-size: .9rem; color: var(--text-meta); display: flex; align-items: center; gap: .5rem; flex-wrap: wrap; }
.soon-chip { font-family: var(--font-mono); font-size: .62rem; letter-spacing: .12em; text-transform: uppercase; border: 1px dashed var(--line); padding: .3rem .5rem; color: var(--text-muted); }
.soon { font-family: var(--font-mono); font-size: .7rem; color: var(--text-muted); }
.empty-note { color: var(--text-meta); font-size: .94rem; background: var(--paper); border: 1px dashed var(--line); padding: 1.2rem; max-width: 60ch; }
footer .footer-links a { margin: 0; }
@media (max-width: 640px) {
  .course-strip { flex-direction: column; align-items: flex-start; }
  .filters input[type="search"] { flex: 1 1 100%; }
}

/* ==========================================================================
   16. PORTRAIT CARD, PAPER GRID, TOPICAL PAPERS
   ========================================================================== */

/* --- the About portrait card, laid out like the Instagram post --- */
.portrait-card {
  background: var(--ink); color: var(--bone);
  border-top: 5px solid var(--acid);
  padding: clamp(1.4rem, 3vw, 2.2rem);
  max-width: 620px; margin-bottom: clamp(2.4rem, 5vw, 3.4rem);
}
.portrait-card img { width: 100%; height: auto; display: block; filter: grayscale(1) contrast(1.05); }
.pcard-eyebrow {
  display: block; font-family: var(--font-mono); font-size: .68rem; font-weight: 500;
  letter-spacing: .24em; text-transform: uppercase; color: var(--acid);
  margin: 1.5rem 0 1.1rem;
}
.pcard-headline {
  font-family: var(--font-sans); font-weight: 700; text-transform: uppercase;
  font-size: clamp(1.9rem, 5.4vw, 2.9rem); line-height: .96; letter-spacing: -.035em;
  margin-bottom: 1.2rem;
}
.pcard-lede { color: var(--on-ink-body); font-size: 1.02rem; line-height: 1.5; max-width: 40ch; }
.pcard-stat {
  margin-top: 1.2rem; font-size: 1.02rem; color: var(--bone);
  padding-top: 1.2rem; border-top: 1px solid rgba(242,243,238,.18);
}
.pcard-stat strong { color: var(--acid); font-weight: 700; }
.pcard-handle {
  display: block; margin-top: 1.4rem; font-family: var(--font-mono);
  font-size: .8rem; color: var(--acid);
}

/* --- the four papers, as equal cards. Every paper reads the same. --- */
.paper-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: clamp(.8rem, 1.6vw, 1.2rem);
}
.paper-card {
  position: relative; display: flex; flex-direction: column;
  background: var(--paper); border: 1px solid var(--line); border-top: 5px solid var(--acid);
  padding: 1.6rem; text-decoration: none; color: var(--ink);
  transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease, background-color .16s ease;
}
.paper-card:hover {
  transform: translateY(-3px); box-shadow: var(--shadow);
  border-color: var(--ink); border-top-color: var(--acid); background: var(--acid-wash);
}
.paper-card .paper-num {
  align-self: flex-start; font-family: var(--font-mono); font-size: .64rem; font-weight: 700;
  letter-spacing: .2em; text-transform: uppercase; color: var(--ink);
  background: var(--acid); border: 1px solid var(--ink); padding: .32rem .6rem;
}
.paper-card .paper-title {
  font-family: var(--font-sans); font-size: 1.22rem; font-weight: 700;
  line-height: 1.1; letter-spacing: -.025em; margin: 1rem 0 .6rem;
}
.paper-card .paper-desc { color: var(--text-meta); font-size: .9rem; margin-bottom: 1.4rem; }
.paper-go {
  margin-top: auto; font-family: var(--font-mono); font-size: .68rem; font-weight: 500;
  letter-spacing: .14em; text-transform: uppercase; color: var(--ink);
  display: inline-flex; align-items: center; gap: .5rem;
}
.paper-go::after { content: "→"; transition: transform .16s ease; }
.paper-card:hover .paper-go::after { transform: translateX(5px); }

/* --- the past papers band under the four paper cards --- */
.papers-band {
  display: flex; align-items: center; justify-content: space-between; gap: 1.6rem; flex-wrap: wrap;
  background: var(--ink); color: var(--bone); border-top: 5px solid var(--acid);
  padding: 1.8rem; margin-top: clamp(1.4rem, 3vw, 2rem);
  text-decoration: none; transition: transform .16s ease, box-shadow .16s ease;
}
.papers-band:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.papers-band p { color: var(--on-ink-body); font-size: .92rem; max-width: 54ch; margin-top: .6rem; }
.papers-band .course-strip-name { margin-top: .9rem; }

/* --- topical past papers list --- */
.topical-list { list-style: none; max-width: 860px; border-top: 1px solid var(--line); }
.topical-row {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem 1.6rem;
  flex-wrap: wrap; padding: 1rem 0; border-bottom: 1px solid var(--line);
}
.topical-name { font-weight: 600; font-size: 1rem; }
.topical-links { display: flex; gap: 1.4rem; flex-wrap: wrap; }

.see-also {
  margin-top: 1.6rem; padding: 1rem 1.2rem; background: var(--acid-wash);
  border-left: 5px solid var(--acid); font-size: .94rem; max-width: 66ch;
}

@media (max-width: 640px) {
  .papers-band { flex-direction: column; align-items: flex-start; }
  .topical-row { flex-direction: column; align-items: flex-start; gap: .5rem; }
}

/* ==========================================================================
   17. COMING SOON STATES
   Nothing on this site is ever a dead link. Anything not ready yet says so.
   ========================================================================== */

.soon-panel {
  background: var(--ink); color: var(--bone); border-top: 5px solid var(--acid);
  padding: clamp(1.6rem, 3.5vw, 2.4rem); max-width: 720px;
  margin-bottom: clamp(2rem, 4vw, 3rem);
}
.soon-panel p { color: var(--on-ink-body); font-size: .98rem; line-height: 1.6; max-width: 54ch; margin: .9rem 0 1.6rem; }
.soon-panel .course-strip-name { margin-top: .9rem; }

/* a topic card for something not written yet */
.chapter-card.is-soon { background: transparent; border-style: dashed; }
.chapter-card.is-soon .chapter-num { background: transparent; color: var(--text-muted); border-color: var(--line); }
.chapter-card.is-soon .chapter-name { color: var(--text-meta); }
.chapter-card.is-soon:hover { background: var(--acid-wash); border-style: solid; border-color: var(--ink); }
.chapter-card.is-soon:hover .chapter-num { background: var(--acid); color: var(--ink); border-color: var(--ink); }
.card-soon {
  position: absolute; right: 1.2rem; top: 1.3rem;
  font-family: var(--font-mono); font-size: .58rem; font-weight: 600;
  letter-spacing: .14em; text-transform: uppercase; color: var(--text-muted);
  border: 1px dashed var(--line); padding: .22rem .4rem;
}
.chapter-card.is-soon::after { content: none; }

/* a download row where the file isn't uploaded yet */
.pending-row {
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  background: transparent; border: 1px dashed var(--line);
  padding: 1rem 1.2rem; color: var(--text-meta); font-size: .95rem;
}

/* --- the per-paper dropdowns on the past papers page --- */
.paper-drop { border: 1px solid var(--line); background: var(--paper); margin-bottom: .7rem; max-width: 900px; }
.paper-drop summary {
  cursor: pointer; padding: 1.1rem 1.3rem; list-style: none;
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  font-family: var(--font-sans); font-weight: 700; font-size: 1.02rem;
  border-left: 5px solid var(--acid);
}
.paper-drop summary::-webkit-details-marker { display: none; }
.paper-drop summary::after { content: "+"; font-family: var(--font-mono); color: var(--acid-deep); font-size: 1.3rem; flex: none; }
.paper-drop[open] summary::after { content: "−"; }
.paper-drop[open] summary { background: var(--acid-wash); border-bottom: 1px solid var(--line); }
.drop-count {
  margin-left: auto; margin-right: .6rem;
  font-family: var(--font-mono); font-size: .62rem; font-weight: 500;
  letter-spacing: .12em; text-transform: uppercase; color: var(--text-muted);
}
.paper-drop .topical-list { border-top: none; padding: 0 1.3rem 1rem; }
.paper-drop .topical-row:last-child { border-bottom: none; }

/* ==========================================================================
   18. GREYED SUBJECT CARDS + PAPER DROPDOWNS
   ========================================================================== */

/* a subject that hasn't been started — visible, but clearly not ready */
.subject-card.is-soon {
  background: transparent; border-style: dashed; cursor: default;
  color: var(--text-meta);
}
.subject-card.is-soon:hover { transform: none; box-shadow: none; background: transparent; border-color: var(--line); }
.subject-card.is-soon::before { display: none; }
.subject-card.is-soon::after { opacity: .028; }
.subject-card.is-soon .subject-tag {
  background: transparent; color: var(--text-muted); border: 1px dashed var(--line);
}
.subject-card.is-soon .subject-title { color: var(--text-meta); }
.subject-card.is-soon .subject-desc { color: var(--text-muted); }
.subject-card.is-soon .subject-go { color: var(--text-muted); }
.subject-card.is-soon .subject-go::after { content: none; }

/* the paper dropdowns used on the A Level Mathematics page */
.paper-drop summary .paper-num { flex: none; }
.drop-name { font-family: var(--font-sans); font-weight: 700; font-size: 1.05rem; letter-spacing: -.02em; }
.drop-desc {
  padding: 1rem 1.3rem 0; color: var(--text-meta); font-size: .9rem; max-width: 62ch;
}
.drop-more { padding: .4rem 1.3rem 1.2rem; font-size: .9rem; }
.paper-drop .topical-name a { font-weight: 600; }
.paper-drop .topical-row { padding: .75rem 0; }

/* ==========================================================================
   19. WHATSAPP REGISTRATION + HOME PAGE ORDER
   There are no forms anywhere on this site. Registration happens on WhatsApp.
   ========================================================================== */

.wa-block {
  display: block; text-decoration: none; color: var(--ink);
  background: var(--paper); border: 1px solid var(--line); border-left: 5px solid var(--acid);
  padding: clamp(1.4rem, 3vw, 2rem); max-width: 620px;
  transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease, background-color .16s ease;
}
.wa-block:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--ink); background: var(--acid-wash); }
.wa-block p { color: var(--text-body); font-size: .95rem; max-width: 46ch; margin-top: .6rem; }
.wa-block .course-strip-name { margin-top: .9rem; }
.wa-number {
  display: inline-block; margin-top: 1.2rem;
  font-family: var(--font-mono); font-size: 1.05rem; font-weight: 700;
  background: var(--acid); color: var(--ink); border: 1px solid var(--ink);
  padding: .6rem .9rem;
}

/* the course band is now a link, and sits above the free resources */
a.course-strip { text-decoration: none; transition: transform .16s ease, box-shadow .16s ease; }
a.course-strip:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
a.course-strip .course-cta { pointer-events: none; }
.resources-block { margin-top: clamp(2.6rem, 5vw, 4rem); }

/* ==========================================================================
   20. HOME PAGE "WHO'S BEHIND THIS" STRIP
   Short, and sends people to /about/ rather than repeating the story here.
   ========================================================================== */

.about-strip { margin-top: clamp(2.6rem, 5vw, 4rem); }
.about-strip-inner {
  display: grid; grid-template-columns: minmax(0, 320px) minmax(0, 1fr);
  gap: clamp(1.4rem, 3vw, 2.4rem); align-items: start;
  background: var(--paper); border: 1px solid var(--line);
  border-top: 5px solid var(--acid); padding: clamp(1.4rem, 3vw, 2rem);
}
.about-strip-inner img { width: 100%; height: auto; display: block; filter: grayscale(1) contrast(1.05); }
.about-strip-inner p { color: var(--text-body); font-size: 1rem; line-height: 1.6; margin-bottom: 1rem; max-width: 56ch; }
.about-strip-inner p:last-child { margin-bottom: 0; }

@media (max-width: 720px) {
  .about-strip-inner { grid-template-columns: 1fr; }
  .about-strip-inner img { max-width: 260px; }
}

/* the "when to use these" line under a resource heading */
.use-when {
  color: var(--text-body); font-size: .95rem; line-height: 1.55;
  max-width: 68ch; margin: -0.6rem 0 1.2rem;
  border-left: 5px solid var(--acid); padding: .2rem 0 .2rem 1rem;
}

/* ==========================================================================
   21. BIG SECTION HEADING ON THE HOME PAGE
   ========================================================================== */

.home-head {
  padding-top: clamp(1.6rem, 3vw, 2.4rem);
  border-top: 5px solid var(--acid);
  margin-bottom: clamp(1.4rem, 3vw, 2rem);
}
.home-head-title {
  font-family: var(--font-sans); font-weight: 700; text-transform: uppercase;
  font-size: clamp(1.9rem, 5vw, 3.1rem); line-height: .98; letter-spacing: -.035em;
  margin-bottom: .9rem;
}
.home-head-sub { color: var(--text-body); font-size: clamp(.98rem, 1.4vw, 1.08rem); max-width: 52ch; }

/* --- two actions per course: register (form) and ask (WhatsApp) --- */
.course-actions { display: flex; flex-wrap: wrap; gap: .7rem; }
.course-cta-alt { background: transparent; color: var(--ink); }
.course-cta-alt:hover { background: var(--ink); color: var(--acid); }

/* the two registration blocks at the foot of the courses page */
.wa-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1rem; max-width: 980px; }
.wa-block-alt { border-left-color: var(--ink); }
.wa-block-alt .wa-number { background: var(--ink); color: var(--acid); }

/* the fee footnote on the courses page */
.fee-note {
  max-width: 720px; margin: 2rem 0 0;
  background: var(--acid-wash); border-left: 5px solid var(--acid);
  padding: 1.1rem 1.2rem;
}
.fee-note p { color: var(--text-body); font-size: .94rem; line-height: 1.6; margin: 0; }

/* ==========================================================================
   22. "COMING SOON" — MADE PROMINENT
   These override the smaller versions defined earlier. A student should be
   able to tell at a glance what's ready and what isn't, without squinting.
   ========================================================================== */

/* the tag used in tables, topical rows and paper lists */
.soon {
  display: inline-block;
  font-family: var(--font-mono); font-size: .74rem; font-weight: 700;
  letter-spacing: .1em; text-transform: uppercase;
  color: var(--acid-deep); background: var(--acid-wash);
  border: 2px dashed rgba(122,98,6,.45);
  padding: .38rem .7rem; white-space: nowrap;
}

/* a download row whose file isn't uploaded yet */
.pending-row {
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  background: var(--acid-wash); border: 2px dashed rgba(122,98,6,.35);
  padding: 1rem 1.2rem; color: var(--text-body); font-size: 1rem; font-weight: 500;
}

/* the "Soon" flag on a topic card */
.card-soon {
  position: absolute; right: 1.1rem; top: 1.2rem;
  font-family: var(--font-mono); font-size: .68rem; font-weight: 700;
  letter-spacing: .12em; text-transform: uppercase;
  color: var(--acid-deep); background: var(--acid-wash);
  border: 2px dashed rgba(122,98,6,.45); padding: .3rem .55rem;
}

/* the counter in a dropdown header, when nothing in it is ready */
.drop-count {
  margin-left: auto; margin-right: .6rem;
  font-family: var(--font-mono); font-size: .72rem; font-weight: 600;
  letter-spacing: .1em; text-transform: uppercase; color: var(--text-meta);
}

/* a whole subject that hasn't started — this is the loudest of them */
.subject-card.is-soon .subject-go {
  display: inline-block; margin-top: 1.6rem;
  font-family: var(--font-mono); font-size: .82rem; font-weight: 700;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--ink); background: var(--acid-wash);
  border: 2px dashed rgba(122,98,6,.5); padding: .6rem .9rem;
}

/* "Coming soon" sitting on the Ink band (course badges, panels) */
.soon-panel .course-badge, .course-soon .course-badge {
  font-size: .74rem; padding: .45rem .8rem;
}

@media (max-width: 640px) {
  .pending-row { flex-direction: column; align-items: flex-start; gap: .6rem; }
}

/* ==========================================================================
   23. "COMING SOON" — LOUD VERSION
   Solid Ink block with Bone text. Acid is reserved for things that ARE
   available, so an unavailable item must not compete with it — Ink is the
   heaviest thing on a Bone page and reads instantly at any size.
   ========================================================================== */

.soon {
  display: inline-block;
  font-family: var(--font-mono); font-size: .82rem; font-weight: 700;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--bone) !important; background: var(--ink) !important;
  border: none !important;
  padding: .5rem .9rem; white-space: nowrap;
}

/* a named download whose file isn't uploaded yet */
.pending-row {
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  background: transparent; border: 2px dashed var(--ink);
  padding: 1.1rem 1.2rem; color: var(--ink); font-size: 1.05rem; font-weight: 600;
}

/* the flag on a topic card that hasn't been written */
.card-soon {
  position: absolute; right: 1.1rem; top: 1.15rem;
  font-family: var(--font-mono); font-size: .74rem; font-weight: 700;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--bone); background: var(--ink); border: none;
  padding: .38rem .6rem;
}

/* a whole subject that hasn't opened — the loudest instance on the site */
.subject-card.is-soon .subject-go {
  display: inline-block; margin-top: 1.8rem;
  font-family: var(--font-mono); font-size: 1rem; font-weight: 700;
  letter-spacing: .16em; text-transform: uppercase;
  color: var(--bone); background: var(--ink); border: none;
  padding: .85rem 1.3rem;
}

/* the counter in a dropdown header */
.drop-count {
  margin-left: auto; margin-right: .6rem;
  font-family: var(--font-mono); font-size: .78rem; font-weight: 700;
  letter-spacing: .12em; text-transform: uppercase; color: var(--text-meta);
}

/* table rows waiting on a file get a faint tint so the row itself reads as pending */
table.papers td:has(.soon) { background: rgba(14,15,13,.035); }

@media (max-width: 640px) {
  .pending-row { flex-direction: column; align-items: flex-start; gap: .7rem; }
  .soon { font-size: .76rem; padding: .45rem .75rem; }
}

/* ==========================================================================
   24. WHATSAPP LINKS — always obviously WhatsApp
   ========================================================================== */

.wa-icon { flex: none; vertical-align: -3px; margin-right: .5rem; }

/* the "ask a question" button on a course card */
.course-cta-wa {
  background: transparent; color: var(--ink);
  display: inline-flex; align-items: center;
}
.course-cta-wa::after { content: none; }
.course-cta-wa:hover { background: var(--ink); color: var(--acid); }

.course-badge-wa { display: inline-flex; align-items: center; }
.contact-icon-wa { display: inline-flex; align-items: center; }
.wa-number { display: inline-flex; align-items: center; }

@media (max-width: 640px) {
  .course-actions { flex-direction: column; align-items: stretch; }
  .course-actions .course-cta { justify-content: center; }
}

/* a note sitting UNDER a table — unlike .use-when it has no negative top
   margin, so it can't ride up into the table's bottom border */
.table-note {
  color: var(--text-meta); font-size: .92rem; line-height: 1.6;
  max-width: 68ch; margin: 1.1rem 0 0;
  border-left: 5px solid var(--acid); padding: .35rem 0 .35rem 1rem;
}

/* a topical slot that isn't ready — label plus the Coming soon block,
   so all three columns line up whether or not the file exists */
.topical-pending {
  display: inline-flex; align-items: center; gap: .5rem;
  color: var(--text-muted); font-size: .95rem;
}
.topical-pending .soon { font-size: .68rem; padding: .3rem .55rem; letter-spacing: .1em; }
.topical-links { display: flex; gap: 1.4rem; flex-wrap: wrap; align-items: center; }
@media (max-width: 640px) {
  .topical-links { gap: .6rem; flex-direction: column; align-items: flex-start; }
}

/* ==========================================================================
   25. TOPICAL PAST PAPERS — as a table, so the columns line up
   ========================================================================== */

.topical-table { font-size: .95rem; }
.topical-table td.topical-name { font-weight: 600; font-family: var(--font-sans); white-space: normal; }
.topical-table th:not(:first-child), .topical-table td:not(:first-child) {
  width: 1%; white-space: nowrap;
}
.paper-drop .table-wrap { border: none; margin: 0; }
.paper-drop .topical-table th { background: transparent; border-bottom: 2px solid var(--ink); }

/* a quiet "Soon" inside a dense list. The dropdown header already carries the
   loud status, so repeating a black block on every row is just noise. */
.soon-lite {
  display: inline-block;
  font-family: var(--font-mono); font-size: .68rem; font-weight: 700;
  letter-spacing: .12em; text-transform: uppercase;
  color: var(--text-muted); border: 1px dashed var(--line);
  padding: .3rem .55rem;
}

@media (max-width: 640px) {
  .topical-table th:not(:first-child), .topical-table td:not(:first-child) {
    width: auto; white-space: normal;
  }
  .paper-drop .table-wrap { border: none; }
}

/* ==========================================================================
   26. "FOUND A MISTAKE?" — on every page that carries documents
   ========================================================================== */

.mistake-band {
  background: var(--ink); color: var(--bone);
  border-top: 5px solid var(--acid);
  padding: clamp(1.5rem, 3.5vw, 2.2rem);
  margin: clamp(2.4rem, 5vw, 3.4rem) 0 0;
  max-width: 780px;
}
.mistake-band p {
  color: var(--on-ink-body); font-size: 1rem; line-height: 1.6;
  max-width: 58ch; margin: 1.1rem 0 1.5rem;
}
.mistake-mail {
  display: inline-block;
  font-family: var(--font-mono); font-size: clamp(1rem, 2.4vw, 1.25rem);
  font-weight: 700; letter-spacing: .02em;
  color: var(--ink); background: var(--acid);
  border: 1px solid var(--acid); padding: .85rem 1.2rem;
  text-decoration: none; word-break: break-word;
  transition: background-color .16s, color .16s, transform .16s, box-shadow .16s;
}
.mistake-mail:hover {
  background: transparent; color: var(--acid);
  transform: translateY(-2px);
}

/* the headline inside the "found a mistake" band */
.mistake-title {
  font-family: var(--font-sans); font-weight: 700; text-transform: uppercase;
  font-size: clamp(1.5rem, 3.4vw, 2.1rem); line-height: 1; letter-spacing: -.03em;
  margin-top: 1.1rem;
}
.mistake-band p:first-of-type { margin-top: 1.1rem; }
.mistake-band p + p { margin-top: -0.4rem; }