/* ==========================================================================
   Design tokens.

   Palette: verdigris (oxidised copper) as the accent, antique gold for
   "in progress", neutrals biased slightly green so they read as chosen
   rather than inherited. Both themes are defined at token level only —
   components never reference a raw colour.
   ========================================================================== */

:root {
  --ground: #f4f6f2;
  --surface: #ffffff;
  --surface-2: #eceeea;
  --ink: #141a18;
  --ink-2: #3d4744;
  --muted: #6b756f;
  --line: #dce0d9;
  --line-strong: #c3c9be;

  --accent: #14706a;
  --accent-ink: #0c4b47;
  --accent-wash: #e2efec;
  --gold: #9a7420;
  --gold-wash: #f4ecd8;
  --crit: #9e3d2d;
  --crit-wash: #f6e5e1;

  --font-display: ui-serif, "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  --rail: 16.5rem;
  --radius: 5px;
  --shadow: 0 1px 2px rgba(20, 26, 24, 0.05), 0 4px 16px rgba(20, 26, 24, 0.04);
}

@media (prefers-color-scheme: dark) {
  :root {
    --ground: #0d110f;
    --surface: #141a17;
    --surface-2: #1b2320;
    --ink: #e5eae6;
    --ink-2: #b9c2bc;
    --muted: #8a948d;
    --line: #242d29;
    --line-strong: #37423c;

    --accent: #4bb3a8;
    --accent-ink: #7fd3c8;
    --accent-wash: #132926;
    --gold: #d0a84e;
    --gold-wash: #2a2416;
    --crit: #d97a68;
    --crit-wash: #2c1a16;

    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 4px 16px rgba(0, 0, 0, 0.3);
  }
}

/* The viewer's theme toggle stamps data-theme on <html>; it must win
   over the media query in BOTH directions, so both are redefined. */
:root[data-theme="dark"] {
  --ground: #0d110f;
  --surface: #141a17;
  --surface-2: #1b2320;
  --ink: #e5eae6;
  --ink-2: #b9c2bc;
  --muted: #8a948d;
  --line: #242d29;
  --line-strong: #37423c;
  --accent: #4bb3a8;
  --accent-ink: #7fd3c8;
  --accent-wash: #132926;
  --gold: #d0a84e;
  --gold-wash: #2a2416;
  --crit: #d97a68;
  --crit-wash: #2c1a16;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 4px 16px rgba(0, 0, 0, 0.3);
}

:root[data-theme="light"] {
  --ground: #f4f6f2;
  --surface: #ffffff;
  --surface-2: #eceeea;
  --ink: #141a18;
  --ink-2: #3d4744;
  --muted: #6b756f;
  --line: #dce0d9;
  --line-strong: #c3c9be;
  --accent: #14706a;
  --accent-ink: #0c4b47;
  --accent-wash: #e2efec;
  --gold: #9a7420;
  --gold-wash: #f4ecd8;
  --crit: #9e3d2d;
  --crit-wash: #f6e5e1;
  --shadow: 0 1px 2px rgba(20, 26, 24, 0.05), 0 4px 16px rgba(20, 26, 24, 0.04);
}

/* ========================================================================== */

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--ground);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-ink); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent); }

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

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  text-wrap: balance;
  margin: 0;
}

p { margin: 0; }

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

/* --- Shell ---------------------------------------------------------------- */

.shell {
  display: grid;
  grid-template-columns: var(--rail) minmax(0, 1fr);
  min-height: 100vh;
}

.rail {
  border-right: 1px solid var(--line);
  background: var(--surface);
  padding: 1.75rem 1.25rem 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
}

.brand { display: flex; flex-direction: column; gap: 0.35rem; }

.brand-mark {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
}

.brand-name {
  font-family: var(--font-display);
  font-size: 1.22rem;
  line-height: 1.15;
  color: var(--ink);
  text-decoration: none;
}
.brand-name:hover { color: var(--accent); }

.rail-heading {
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.6rem;
}

.rail-list { display: flex; flex-direction: column; gap: 0.15rem; }

.rail-link {
  display: block;
  padding: 0.45rem 0.6rem;
  border-radius: var(--radius);
  color: var(--ink-2);
  text-decoration: none;
  font-size: 0.9rem;
  border-left: 2px solid transparent;
}
.rail-link:hover { background: var(--surface-2); color: var(--ink); }
.rail-link.is-active {
  background: var(--accent-wash);
  border-left-color: var(--accent);
  color: var(--accent-ink);
  font-weight: 600;
}

.rail-link-sub {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--muted);
  display: block;
}

.rail-foot {
  margin-top: auto;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  font-size: 0.78rem;
  color: var(--muted);
}

.ghost-btn {
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  padding: 0.35rem 0.7rem;
  font-size: 0.78rem;
  color: var(--ink-2);
  text-align: left;
}
.ghost-btn:hover { border-color: var(--accent); color: var(--accent-ink); }

.main { padding: 3rem 3rem 6rem; min-width: 0; }
.wrap { max-width: 60rem; margin: 0 auto; }
.prose { max-width: 40rem; }

/* --- Generic pieces ------------------------------------------------------- */

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.lede { font-size: 1.06rem; color: var(--ink-2); }

.stack { display: flex; flex-direction: column; }
.stack-xs { gap: 0.4rem; }
.stack-sm { gap: 0.75rem; }
.stack-md { gap: 1.25rem; }
.stack-lg { gap: 2.25rem; }
.stack-xl { gap: 3.5rem; }

.divider { height: 1px; background: var(--line); border: 0; margin: 0; }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.35rem 1.5rem;
  box-shadow: var(--shadow);
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.16rem 0.45rem;
  border-radius: 3px;
  background: var(--surface-2);
  color: var(--muted);
  white-space: nowrap;
}
.tag-accent { background: var(--accent-wash); color: var(--accent-ink); }
.tag-gold { background: var(--gold-wash); color: var(--gold); }
.tag-crit { background: var(--crit-wash); color: var(--crit); }

.tag-row { display: flex; flex-wrap: wrap; gap: 0.4rem; align-items: center; }

/* --- Home ----------------------------------------------------------------- */

.hero { display: flex; flex-direction: column; gap: 1rem; padding-bottom: 0.5rem; }
.hero h1 { font-size: clamp(2rem, 4.5vw, 2.9rem); }

.path-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(19rem, 1fr));
  gap: 1rem;
}

.path-card {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  text-decoration: none;
  color: inherit;
  border-top: 3px solid var(--line-strong);
}
.path-card:hover { border-top-color: var(--accent); color: inherit; }
.path-card h3 { font-size: 1.25rem; }
.path-card p { font-size: 0.9rem; color: var(--ink-2); }

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.1rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

/* --- Progress ------------------------------------------------------------- */

.meter {
  height: 4px;
  background: var(--surface-2);
  border-radius: 2px;
  overflow: hidden;
}
.meter-fill { height: 100%; background: var(--accent); transition: width 0.25s ease; }

.meter-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
}

/* --- Phase spine ---------------------------------------------------------- */
/* Phases really are a gated sequence, so the numbering carries information. */

.spine { display: flex; flex-direction: column; }

.spine-item {
  display: grid;
  grid-template-columns: 3rem minmax(0, 1fr);
  gap: 1.25rem;
  text-decoration: none;
  color: inherit;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--line);
  position: relative;
}
.spine-item:first-child { border-top: 1px solid var(--line); }
.spine-item:hover { color: inherit; }
.spine-item:hover .spine-title { color: var(--accent-ink); }

.spine-node {
  width: 2.35rem;
  height: 2.35rem;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--muted);
  background: var(--surface);
  font-variant-numeric: tabular-nums;
}
.spine-node.is-done { background: var(--accent); border-color: var(--accent); color: #fff; }
.spine-node.is-active { border-color: var(--gold); color: var(--gold); background: var(--gold-wash); }

.spine-body { display: flex; flex-direction: column; gap: 0.45rem; min-width: 0; }
.spine-title { font-family: var(--font-display); font-size: 1.14rem; font-weight: 600; }
.spine-goal { font-size: 0.88rem; color: var(--muted); }

/* --- Modules -------------------------------------------------------------- */

.module {
  border: 1px solid var(--line);
  border-left: 3px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 1.25rem 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}
.module.is-done { border-left-color: var(--accent); }
.module.is-critical { border-left-color: var(--gold); }

.module-head { display: flex; gap: 0.85rem; align-items: flex-start; }
.module-head h4 { font-size: 1.05rem; }
.module-head-text { display: flex; flex-direction: column; gap: 0.3rem; min-width: 0; flex: 1; }

.check {
  appearance: none;
  -webkit-appearance: none;
  width: 1.15rem;
  height: 1.15rem;
  min-width: 1.15rem;
  margin-top: 0.2rem;
  border: 1.5px solid var(--line-strong);
  border-radius: 3px;
  background: var(--surface);
  cursor: pointer;
  display: grid;
  place-items: center;
}
.check:hover { border-color: var(--accent); }
.check:checked { background: var(--accent); border-color: var(--accent); }
.check:checked::after {
  content: "";
  width: 0.3rem;
  height: 0.58rem;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: translateY(-1px) rotate(45deg);
}

.sub-label {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.topic-list, .plain-list {
  margin: 0;
  padding-left: 1.1rem;
  font-size: 0.9rem;
  color: var(--ink-2);
  display: flex;
  flex-direction: column;
  gap: 0.28rem;
}
.topic-list li::marker { color: var(--line-strong); }

/* --- Resources ------------------------------------------------------------ */

.res-list { display: flex; flex-direction: column; gap: 0.5rem; }

.res {
  display: grid;
  grid-template-columns: 4.6rem minmax(0, 1fr);
  gap: 0.85rem;
  align-items: baseline;
  padding: 0.5rem 0.65rem;
  border-radius: var(--radius);
  background: var(--surface-2);
}

.res-type {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  border-right: 1px solid var(--line-strong);
  padding-right: 0.5rem;
}
.res-type[data-t="video"] { color: var(--crit); }
.res-type[data-t="course"] { color: var(--accent); }
.res-type[data-t="book"] { color: var(--gold); }

.res-name { font-size: 0.9rem; font-weight: 600; }
.res-note { font-size: 0.83rem; color: var(--muted); display: block; margin-top: 0.1rem; }
.res-cost {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-left: 0.4rem;
}
.res-cost[data-c="free"] { color: var(--accent); }
.res-cost[data-c="paid"] { color: var(--gold); }

/* --- Quiz ----------------------------------------------------------------- */

.quiz-item {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 1.1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.quiz-q { font-size: 0.96rem; font-weight: 600; display: flex; gap: 0.7rem; }
.quiz-num {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.opt-list { display: flex; flex-direction: column; gap: 0.4rem; }

.opt {
  text-align: left;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.55rem 0.8rem;
  font-size: 0.9rem;
  color: var(--ink-2);
  background: var(--surface);
  display: flex;
  gap: 0.6rem;
}
.opt:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-wash); }
.opt:disabled { cursor: default; }
.opt.is-correct { border-color: var(--accent); background: var(--accent-wash); color: var(--accent-ink); font-weight: 600; }
.opt.is-wrong { border-color: var(--crit); background: var(--crit-wash); color: var(--crit); }
.opt-key { font-family: var(--font-mono); font-size: 0.78rem; opacity: 0.7; }

.reveal {
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  padding: 0.6rem 0.85rem;
  font-size: 0.88rem;
  color: var(--muted);
  text-align: left;
  width: 100%;
}
.reveal:hover { border-color: var(--accent); color: var(--accent-ink); }

.answer {
  font-size: 0.9rem;
  border-left: 2px solid var(--accent);
  padding-left: 0.85rem;
  color: var(--ink-2);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.answer .why { color: var(--muted); font-size: 0.85rem; }

.hidden { display: none; }

/* --- Callouts ------------------------------------------------------------- */

.callout {
  border-radius: var(--radius);
  padding: 1.1rem 1.35rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.92rem;
}
.callout-accent { background: var(--accent-wash); color: var(--accent-ink); }
.callout-gold { background: var(--gold-wash); color: var(--gold); }
.callout-crit { background: var(--crit-wash); color: var(--crit); }
.callout .sub-label { color: inherit; opacity: 0.75; }

/* --- Gate ----------------------------------------------------------------- */

.gate {
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 1.35rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.gate.is-passed { border-color: var(--accent); }

.gate-item {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  font-size: 0.92rem;
  color: var(--ink-2);
  cursor: pointer;
}
.gate-item:hover { color: var(--ink); }

.gate-verdict {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.gate.is-passed .gate-verdict { color: var(--accent); }

/* --- Tables --------------------------------------------------------------- */

.table-scroll { overflow-x: auto; }

table { border-collapse: collapse; width: 100%; font-size: 0.88rem; }
th, td { text-align: left; padding: 0.55rem 0.8rem; border-bottom: 1px solid var(--line); }
th {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 500;
}
td { font-variant-numeric: tabular-nums; color: var(--ink-2); }

/* --- Breadcrumb / phase nav ----------------------------------------------- */

.crumb {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--muted);
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.crumb a { color: var(--muted); text-decoration: none; }
.crumb a:hover { color: var(--accent-ink); text-decoration: underline; }

.pager { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.pager a {
  font-size: 0.88rem;
  text-decoration: none;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  padding: 0.55rem 0.9rem;
  color: var(--ink-2);
}
.pager a:hover { border-color: var(--accent); color: var(--accent-ink); }

/* --- Mobile --------------------------------------------------------------- */

.rail-toggle { display: none; }

@media (max-width: 62rem) {
  .shell { grid-template-columns: minmax(0, 1fr); }
  .rail {
    position: static;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .rail-body.is-collapsed { display: none; }
  /* The footer controls live outside .rail-body so they can pin to the bottom
     on desktop; on mobile they have to collapse along with the menu. */
  .rail-body.is-collapsed ~ .rail-foot { display: none; }
  .rail-toggle {
    display: block;
    align-self: flex-start;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--accent-ink);
  }
  .main { padding: 2rem 1.25rem 4rem; }
  .res { grid-template-columns: minmax(0, 1fr); gap: 0.2rem; }
  .res-type { border-right: 0; padding-right: 0; }
  .spine-item { grid-template-columns: 2.6rem minmax(0, 1fr); gap: 0.9rem; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}

@media print {
  .rail, .pager, .ghost-btn { display: none; }
  .shell { grid-template-columns: 1fr; }
  .hidden { display: block; }
}
