/* ============================================================
   Learning Hub — hub-only stylesheet (light + dark)
   The hub is the platform's front door: same family tokens as the
   courses (CNPE lineage), plus a complete dark theme.
   Theme mechanism (see CONTRACT.md): color-scheme light dark;
   defaults follow prefers-color-scheme; :root[data-theme] wins both ways.
   Type: Space Grotesk (display) · IBM Plex Sans (body) · JetBrains Mono (code)
   ============================================================ */


/* ---- self-hosted fonts (SIL Open Font License) — deduped shared files,
   one rule per family+subset with a weight RANGE (files are byte-identical
   across weights, so each serves the whole range) ---- */
@font-face {
  font-family: 'IBM Plex Sans';
  font-style: normal;
  font-weight: 400 600;
  font-stretch: 100%;
  font-display: swap;
  src: url(../fonts/ibm-plex-sans-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: 'IBM Plex Sans';
  font-style: normal;
  font-weight: 400 600;
  font-stretch: 100%;
  font-display: swap;
  src: url(../fonts/ibm-plex-sans-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 400 500;
  font-display: swap;
  src: url(../fonts/jetbrains-mono-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: 'JetBrains Mono';
  font-style: normal;
  font-weight: 400 500;
  font-display: swap;
  src: url(../fonts/jetbrains-mono-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'Space Grotesk';
  font-style: normal;
  font-weight: 500 700;
  font-display: swap;
  src: url(../fonts/space-grotesk-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: 'Space Grotesk';
  font-style: normal;
  font-weight: 500 700;
  font-display: swap;
  src: url(../fonts/space-grotesk-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* ---------- tokens: light (default) ---------- */
:root {
  color-scheme: light dark;

  /* surfaces */
  --bg:           #F4F6F9;
  --surface:      #FFFFFF;
  --surface-2:    #FAFBFD;
  --border:       #E4E8EF;
  --border-strong:#CBD3DF;

  /* ink */
  --ink:          #141E2C;
  --ink-soft:     #46546A;
  --ink-faint:    #586479;
  --link:         #4338CA;

  /* spectrum anchors — the family signature */
  --indigo:       #4F46E5;
  --indigo-deep:  #4338CA;
  --violet:       #7C3AED;
  --pink:         #DB2777;
  --amber:        #E8890C;
  --spectrum: linear-gradient(90deg, #4F46E5 0%, #7C3AED 38%, #DB2777 68%, #E8890C 100%);

  /* hub-specific */
  --shadow:       rgba(8, 12, 20, 0.10);
  --hero-glow-1:  rgba(79, 70, 229, 0.10);
  --hero-glow-2:  rgba(232, 137, 12, 0.12);
  --badge-bg:     #FDF6EC;
  --badge-ink:    #8A5208;
  --badge-line:   #E8890C;
  --focus-ring:   #4F46E5;

  --radius: 12px;
  --radius-sm: 8px;
  --measure-wide: 1160px;

  --font-display: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  --font-body: "IBM Plex Sans", ui-sans-serif, system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
}

/* ---------- tokens: dark (system default) ---------- */
@media (prefers-color-scheme: dark) {
  :root {
    --bg:           #0D1320;
    --surface:      #161E2E;
    --surface-2:    #121927;
    --border:       #263248;
    --border-strong:#38455F;

    --ink:          #E7EDF6;
    --ink-soft:     #A9B6C9;
    --ink-faint:    #8595AD;
    --link:         #A5B4FC;

    --shadow:       rgba(0, 0, 0, 0.45);
    --hero-glow-1:  rgba(99, 102, 241, 0.16);
    --hero-glow-2:  rgba(232, 137, 12, 0.10);
    --badge-bg:     rgba(232, 137, 12, 0.14);
    --badge-ink:    #F2B45A;
    --badge-line:   #C2710A;
    --focus-ring:   rgba(129, 140, 248, 0.65);
  }
}

/* ---------- explicit overrides — must win in BOTH directions ---------- */
:root[data-theme="light"] {
  color-scheme: light;

  --bg:           #F4F6F9;
  --surface:      #FFFFFF;
  --surface-2:    #FAFBFD;
  --border:       #E4E8EF;
  --border-strong:#CBD3DF;

  --ink:          #141E2C;
  --ink-soft:     #46546A;
  --ink-faint:    #586479;
  --link:         #4338CA;

  --shadow:       rgba(8, 12, 20, 0.10);
  --hero-glow-1:  rgba(79, 70, 229, 0.10);
  --hero-glow-2:  rgba(232, 137, 12, 0.12);
  --badge-bg:     #FDF6EC;
  --badge-ink:    #8A5208;
  --badge-line:   #E8890C;
  --focus-ring:   #4F46E5;
}
:root[data-theme="dark"] {
  color-scheme: dark;

  --bg:           #0D1320;
  --surface:      #161E2E;
  --surface-2:    #121927;
  --border:       #263248;
  --border-strong:#38455F;

  --ink:          #E7EDF6;
  --ink-soft:     #A9B6C9;
  --ink-faint:    #8595AD;
  --link:         #A5B4FC;

  --shadow:       rgba(0, 0, 0, 0.45);
  --hero-glow-1:  rgba(99, 102, 241, 0.16);
  --hero-glow-2:  rgba(232, 137, 12, 0.10);
  --badge-bg:     rgba(232, 137, 12, 0.14);
  --badge-ink:    #F2B45A;
  --badge-line:   #C2710A;
  --focus-ring:   rgba(129, 140, 248, 0.65);
}

/* ---------- base ---------- */
* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--link); }

h1, h2, h3 { font-family: var(--font-display); color: var(--ink); }

/* ---- skip-to-content link (accessibility) ---- */
.skip-link {
  position: absolute; left: 8px; top: -48px; z-index: 1000;
  background: var(--indigo-deep); color: #fff;
  padding: 0.55rem 0.9rem; border-radius: var(--radius-sm);
  font-weight: 600; font-size: 0.9rem; text-decoration: none;
  transition: top 0.15s ease;
}
.skip-link:focus { top: 8px; outline: 3px solid #fff; outline-offset: 2px; }

/* ---------- header ---------- */
/* the signature spectrum, as a hairline across the very top */
.hub-topline { height: 4px; background: var(--spectrum); }

.hub-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.hub-header-inner {
  max-width: var(--measure-wide); margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
}
.wordmark {
  display: inline-flex; align-items: center; gap: 0.6rem;
  text-decoration: none; color: var(--ink);
  font-family: var(--font-display); font-weight: 700; font-size: 1.12rem;
  letter-spacing: 0.01em;
}
.wordmark-mark {
  width: 22px; height: 22px; border-radius: 6px;
  background: var(--spectrum);
  flex: none;
}

.theme-toggle {
  display: inline-flex; align-items: center; gap: 0.45rem;
  font-family: var(--font-display); font-weight: 600; font-size: 0.84rem;
  color: var(--ink-soft);
  background: var(--surface);
  border: 1px solid var(--border-strong); border-radius: 99px;
  padding: 0.32rem 0.85rem; cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.theme-toggle:hover { border-color: var(--indigo); color: var(--ink); }
.theme-toggle-icon { font-size: 0.95em; line-height: 1; }

/* ---------- main + hero ---------- */
.hub-main {
  max-width: var(--measure-wide); margin: 0 auto;
  padding: 2.4rem 1.5rem 4rem;
}

.hub-hero {
  border-radius: 18px;
  background:
    radial-gradient(120% 140% at 0% 0%, var(--hero-glow-1), transparent 55%),
    radial-gradient(120% 140% at 100% 100%, var(--hero-glow-2), transparent 55%),
    var(--surface);
  border: 1px solid var(--border);
  padding: 2.6rem 2.4rem;
}
.eyebrow {
  display: inline-flex; align-items: center; gap: 0.5rem; margin: 0;
  font-family: var(--font-mono); font-size: 0.72rem;
  letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-faint);
}
.eyebrow .dot { width: 8px; height: 8px; border-radius: 99px; background: var(--spectrum); flex: none; }
.hub-hero h1 {
  margin: 0.7rem 0 0;
  font-weight: 700; font-size: clamp(2rem, 5vw, 2.9rem);
  line-height: 1.12; letter-spacing: -0.01em;
}
.hub-hero .lead {
  margin: 1rem 0 0; max-width: 62ch;
  font-size: 1.05rem; color: var(--ink-soft);
}

/* ---------- course grid ---------- */
.hub-courses { margin-top: 2.6rem; }
.hub-courses h2 { margin: 0; font-size: 1.35rem; }
.section-note { margin: 0.35rem 0 0; font-size: 0.88rem; color: var(--ink-faint); }

.course-grid {
  display: grid; grid-template-columns: 1fr;
  gap: 1.1rem; margin-top: 1.4rem;
}
@media (min-width: 720px)  { .course-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1080px) { .course-grid { grid-template-columns: repeat(3, 1fr); } }

.course-card {
  position: relative;
  display: flex;
  text-decoration: none; color: inherit;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.15s, transform 0.15s, box-shadow 0.15s;
}
.course-card:hover {
  border-color: var(--card-accent, var(--indigo));
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--shadow);
}
.course-card-bar {
  flex: 0 0 6px;
  background: var(--card-accent, var(--indigo));
}
.course-card-body {
  flex: 1; min-width: 0;
  display: flex; flex-direction: column; gap: 0.5rem;
  padding: 1.15rem 1.3rem 1.2rem;
}
.course-card-title {
  font-family: var(--font-display); font-weight: 600;
  font-size: 1.08rem; line-height: 1.35; color: var(--ink);
}
.course-card-desc {
  font-size: 0.88rem; line-height: 1.55; color: var(--ink-soft);
}
.course-card-meta {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0.4rem;
  margin-top: auto; padding-top: 0.35rem;
}
.course-card-pages {
  font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-faint);
  margin-right: 0.2rem;
}
.course-card-chip {
  font-family: var(--font-mono); font-size: 0.68rem;
  color: var(--ink-soft);
  border: 1px solid var(--border-strong); border-radius: 99px;
  padding: 0.12rem 0.55rem;
}

/* drafts wear a badge (markup injected by build.js inside the card body) */
.course-card-badge {
  order: -1; align-self: flex-start;
  font-family: var(--font-display); font-weight: 600; font-size: 0.66rem;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--badge-ink); background: var(--badge-bg);
  border: 1px solid var(--badge-line); border-radius: 99px;
  padding: 0.1rem 0.55rem;
}

/* standalone islands get a small note — pure CSS, no extra markup */
.course-card[data-generation="standalone"] .course-card-body::after {
  content: "Own look & feel";
  font-size: 0.72rem; font-style: italic; color: var(--ink-faint);
  margin-top: 0.1rem;
}

/* ---------- footer ---------- */
.hub-foot { margin-top: 2rem; border-top: 1px solid var(--border); }
.hub-foot-inner {
  max-width: var(--measure-wide); margin: 0 auto;
  padding: 1.6rem 1.5rem 2.2rem;
  font-size: 0.82rem; color: var(--ink-faint);
}
.hub-foot .spectrum-bar {
  height: 4px; border-radius: 99px; background: var(--spectrum);
  max-width: 160px; margin-bottom: 1rem;
}
.hub-foot p { margin: 0.35rem 0; }
.hub-foot a { color: var(--ink-soft); }

/* ---------- focus visibility ---------- */
a:focus-visible, button:focus-visible {
  outline: 3px solid var(--focus-ring); outline-offset: 2px; border-radius: 4px;
}

/* ---------- responsive ---------- */
@media (max-width: 719.98px) {
  .hub-main { padding: 1.8rem 1.1rem 3.4rem; }
  .hub-header-inner { padding: 0.75rem 1.1rem; }
  .hub-hero { padding: 1.8rem 1.4rem; }
  .theme-toggle-text { display: none; }  /* icon-only toggle on small screens */
  .theme-toggle { padding: 0.32rem 0.6rem; }
}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .skip-link, .theme-toggle, .course-card { transition: none; }
  .course-card:hover { transform: none; }
}

/* ---------- print: clean, chrome-free ---------- */
@media print {
  .hub-topline, .skip-link, .theme-toggle { display: none !important; }
  body, .hub-header, .hub-hero, .course-card { background: #fff !important; color: #000 !important; }
  .hub-hero, .course-card, .hub-header, .hub-foot { border-color: #ccc !important; }
  .course-card { break-inside: avoid; page-break-inside: avoid; box-shadow: none !important; }
  .course-card-title, .course-card-desc, .hub-foot-inner { color: #000 !important; }
  a { color: #000 !important; text-decoration: underline; }
}