/* ===== Theme variables — one skin set per data-theme value ===== */
:root,
:root[data-theme="corporate-ops"] {
  --bg: #0B0F14;
  --bg-elevated: #0E141B;
  --surface: #111820;
  --surface-deep: #05080C;
  --text: #E6EDF3;
  --text-muted: #9AA7B4;
  --border: #233040;
  --accent: #4CC9F0;
  --accent-ink: #0B0F14;
  --accent-soft: #9BE3F7;
  --secondary: var(--accent);
  --warn: #FFB454;
  --warn-bg: var(--surface);
  --warn-border: var(--border);
  --radius: 2px;
  --font-display: "Space Grotesk", sans-serif;
  --font-body: "IBM Plex Sans", sans-serif;
  --font-mono: "JetBrains Mono", monospace;
}

:root[data-theme="terminal"] {
  --bg: #0A0E0A;
  --bg-elevated: #0A0E0A;
  --surface: #0A0E0A;
  --surface-deep: #050805;
  --text: #D4F5D2;
  --text-muted: #8DB98A;
  --border: #2B4A2E;
  --accent: #5CFF9D;
  --accent-ink: #0A0E0A;
  --accent-soft: #B8FFD3;
  --secondary: var(--accent);
  --warn: #E8C547;
  --warn-bg: var(--surface);
  --warn-border: var(--warn);
  --radius: 0px;
  --font-display: "IBM Plex Mono", monospace;
  --font-body: "IBM Plex Sans", sans-serif;
  --font-mono: "IBM Plex Mono", monospace;
}

:root[data-theme="solarpunk"] {
  --bg: #F2EFE4;
  --bg-elevated: #17573F;
  --surface: #FFFFFF;
  --surface-deep: #1C2620;
  --text: #1C2620;
  --text-muted: #4A5A50;
  --border: #D5D0BF;
  --accent: #17573F;
  --accent-ink: #F2EFE4;
  --accent-soft: #D9E8DC;
  --secondary: #F4C15D;
  --tertiary: #9A4F12;
  --warn: #7A3D0C;
  --warn-bg: #FBE7C2;
  --warn-border: #FBE7C2;
  --radius: 18px;
  --font-display: "Bricolage Grotesque", sans-serif;
  --font-body: "Atkinson Hyperlegible", sans-serif;
  --font-mono: "JetBrains Mono", monospace;
}

:root[data-theme="neon-noir"] {
  --bg: #0D0A14;
  --bg-elevated: #0D0A14;
  --surface: #1A1326;
  --surface-deep: #07050B;
  --text: #EDE6F7;
  --text-muted: #A99BBF;
  --border: #3A2C52;
  --accent: #3EE6E0;
  --accent-ink: #0D0A14;
  --accent-soft: #A6F5F2;
  --secondary: #FF5CBE;
  --warn: #F5D547;
  --warn-bg: var(--surface);
  --warn-border: var(--warn);
  --radius: 4px;
  --font-display: "Chakra Petch", sans-serif;
  --font-body: "IBM Plex Sans", sans-serif;
  --font-mono: "JetBrains Mono", monospace;
}

/* ===== Base (shared mechanics, not skin-specific look) ===== */
* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  min-height: 100vh;
}
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-soft); }
img { max-width: 100%; }
code, pre { font-family: var(--font-mono); }
pre {
  background: var(--surface-deep);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 20px;
  overflow-x: auto;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text);
}
pre code { background: none; padding: 0; }
:not(pre) > code {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 2px 6px;
  font-size: 0.9em;
}
:root[data-theme="neon-noir"] pre { border-left-color: var(--secondary); }
:root[data-theme="terminal"] pre { border-left: 1px solid var(--border); }
:root[data-theme="solarpunk"] pre { border-left: none; }

/* ===== Header shell ===== */
.site-header { border-bottom: 1px solid var(--border); background: var(--bg-elevated); }
:root[data-theme="terminal"] .site-header { border-bottom-style: dashed; }
:root[data-theme="solarpunk"] .site-header { background: var(--bg-elevated); color: var(--accent-ink); }
.site-header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
}
.site-nav { display: flex; flex-wrap: wrap; gap: 24px; font-family: var(--font-mono); font-size: 13px; }
.site-nav a { color: var(--text); }
:root[data-theme="solarpunk"] .site-nav a { color: var(--accent-ink); font-family: var(--font-body); font-size: 16px; }
:root[data-theme="corporate-ops"] .site-nav a,
:root[data-theme="neon-noir"] .site-nav a { text-transform: uppercase; letter-spacing: 0.06em; }
:root[data-theme="neon-noir"] .site-nav a { font-family: var(--font-display); font-size: 15px; font-weight: 700; }
:root[data-theme="terminal"] .site-nav a { text-transform: lowercase; }
:root[data-theme="terminal"] .site-nav a::before { content: "./"; }
.site-nav a:hover { color: var(--accent); }
:root[data-theme="solarpunk"] .site-nav a:hover { color: var(--secondary); }

.theme-switcher { display: flex; align-items: center; gap: 8px; font-family: var(--font-mono); font-size: 12px; color: var(--text-muted); }
:root[data-theme="solarpunk"] .theme-switcher { color: var(--accent-soft); }
.theme-switcher select {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 6px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
}

.brand-link { display: contents; color: inherit; text-decoration: none; }

/* ---- Brand slot: 4 variants, one shown at a time ---- */
.brand-corporate-ops, .brand-terminal, .brand-solarpunk, .brand-neon-noir { display: none; align-items: center; gap: 12px; color: inherit; }
:root[data-theme="corporate-ops"] .brand-corporate-ops,
:root[data-theme="terminal"] .brand-terminal,
:root[data-theme="solarpunk"] .brand-solarpunk,
:root[data-theme="neon-noir"] .brand-neon-noir { display: flex; }

.brand-corporate-ops { font-family: var(--font-display); font-weight: 700; letter-spacing: 0.12em; font-size: 15px; }
.brand-corporate-ops .accent { color: var(--accent); }

.brand-terminal { font-family: var(--font-mono); font-size: 14px; color: var(--text-muted); }
.brand-terminal .accent { color: var(--accent); }
.brand-terminal .path { color: #7FD4FF; }
.cursor-blink { display: inline-block; width: 9px; height: 15px; background: var(--accent); vertical-align: -2px; margin-left: 4px; animation: blink 1.1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }

.brand-solarpunk { font-family: var(--font-display); font-weight: 800; font-size: 20px; }

.brand-neon-noir { font-family: var(--font-display); font-weight: 700; font-size: 20px; letter-spacing: 0.08em; }
.brand-neon-noir .pink { color: var(--secondary); }
.brand-neon-noir .cyan { color: var(--accent); }

/* ===== Footer ===== */
.site-footer { border-top: 1px solid var(--border); margin-top: 64px; }
:root[data-theme="terminal"] .site-footer { border-top-style: dashed; }
:root[data-theme="solarpunk"] .site-footer { border-top-width: 2px; }
.site-footer-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
}
:root[data-theme="solarpunk"] .site-footer-inner { font-family: var(--font-body); font-size: 15px; }
.footer-changelog-standard { display: inline; }
.footer-changelog-terminal { display: none; }
:root[data-theme="terminal"] .footer-changelog-standard { display: none; }
:root[data-theme="terminal"] .footer-changelog-terminal { display: inline; }

/* ===== Hub / general content pages (no mockup to match — kept simple) ===== */
.hub-page { max-width: 880px; margin: 0 auto; padding: 48px 24px; }
.hub-page h1 { font-family: var(--font-display); font-size: 44px; margin: 0 0 16px; }
.hub-page h2 { font-family: var(--font-display); font-size: 28px; margin: 40px 0 12px; }
.hub-page p { font-size: 18px; line-height: 1.7; max-width: 68ch; }
.classes-home { max-width: 1280px; }

.course-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; margin-top: 32px; }
.course-card { display: block; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; color: var(--text); }
.course-card:hover { border-color: var(--accent); }
.course-card-term { font-family: var(--font-mono); font-size: 12px; color: var(--accent); letter-spacing: 0.06em; }
.course-card h3 { font-family: var(--font-display); margin: 8px 0 4px; }
.course-card p { font-size: 15px; color: var(--text-muted); margin: 0; }

/* ===== Page shells ===== */
.course-shell, .chapter-layout { max-width: 1280px; margin: 0 auto; padding: 32px 24px; }
.chapter-layout { display: flex; flex-wrap: wrap; gap: 40px; }
.chapter-main { flex: 999 1 560px; min-width: 0; }
.chapter-main h2 { font-family: var(--font-display); font-size: 26px; margin: 40px 0 12px; }
.chapter-main p { font-size: 18px; line-height: 1.7; max-width: 68ch; margin: 0 0 16px; }
:root[data-theme="terminal"] .chapter-main h2::before { content: "## "; color: var(--text-muted); }
:root[data-theme="terminal"] .chapter-main h2 { font-family: var(--font-mono); color: var(--accent); }

/* ===== Sidebar: 4 variants ===== */
.sidebar-corporate-ops, .sidebar-terminal, .sidebar-solarpunk, .sidebar-neon-noir { display: none; flex: 1 1 220px; font-size: 13px; }
:root[data-theme="corporate-ops"] .sidebar-corporate-ops,
:root[data-theme="terminal"] .sidebar-terminal,
:root[data-theme="solarpunk"] .sidebar-solarpunk,
:root[data-theme="neon-noir"] .sidebar-neon-noir { display: block; }

.sidebar-label-corporate-ops { color: var(--text-muted); letter-spacing: 0.12em; margin-bottom: 16px; font-family: var(--font-mono); font-size: 12px; }
.sidebar-corporate-ops ol { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 4px; font-family: var(--font-mono); }
.sidebar-corporate-ops a { display: block; padding: 10px 12px; color: var(--text-muted); }
.sidebar-corporate-ops a[aria-current="page"] { color: var(--accent-ink); background: var(--accent); font-weight: 600; }

.sidebar-label-terminal { color: var(--text-muted); margin-bottom: 12px; font-family: var(--font-mono); }
.sidebar-terminal ol { list-style: none; margin: 0; padding: 0; font-family: var(--font-mono); }
.sidebar-terminal li { padding: 8px 0; color: var(--text-muted); }
.sidebar-terminal a { color: var(--text-muted); }
.sidebar-terminal li.is-current a { color: var(--accent); font-weight: 600; }

.sidebar-label-solarpunk { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.1em; color: var(--text-muted); margin-bottom: 12px; }
.sidebar-solarpunk ol { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; font-size: 16px; }
.sidebar-solarpunk a { display: block; padding: 10px 14px; border-radius: 12px; color: var(--text); }
.sidebar-solarpunk a.is-current { background: var(--accent-soft); color: var(--accent); font-weight: 700; }

.sidebar-label-neon-noir { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.14em; color: var(--text-muted); margin-bottom: 14px; }
.sidebar-neon-noir ol { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; font-family: var(--font-display); font-size: 15px; }
.sidebar-neon-noir a { display: block; padding: 10px 14px; color: var(--text-muted); }
.sidebar-neon-noir a.is-current { color: var(--accent-ink); background: var(--secondary); font-weight: 700; clip-path: polygon(0 0, 100% 0, 100% 70%, 92% 100%, 0 100%); }

/* ===== Chapter hero: 4 variants ===== */
.chapter-hero-corporate-ops, .chapter-hero-terminal, .chapter-hero-solarpunk, .chapter-hero-neon-noir,
.course-hero-corporate-ops, .course-hero-terminal, .course-hero-solarpunk, .course-hero-neon-noir { display: none; }
:root[data-theme="corporate-ops"] .chapter-hero-corporate-ops, :root[data-theme="corporate-ops"] .course-hero-corporate-ops { display: flex; }
:root[data-theme="terminal"] .chapter-hero-terminal, :root[data-theme="terminal"] .course-hero-terminal { display: block; }
:root[data-theme="solarpunk"] .chapter-hero-solarpunk, :root[data-theme="solarpunk"] .course-hero-solarpunk { display: block; }
:root[data-theme="neon-noir"] .chapter-hero-neon-noir, :root[data-theme="neon-noir"] .course-hero-neon-noir { display: block; }

/* corporate ops: giant outlined number + eyebrow + title */
.chapter-hero-corporate-ops { align-items: flex-end; gap: 24px; border-bottom: 1px solid var(--border); padding-bottom: 24px; }
.chapter-num-corporate-ops { font-family: var(--font-display); font-size: 110px; line-height: 0.8; font-weight: 700; color: transparent; -webkit-text-stroke: 2px var(--accent); }
.chapter-eyebrow-corporate-ops { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.16em; color: var(--accent); }
.chapter-hero-corporate-ops h1 { margin: 8px 0 0; font-family: var(--font-display); font-size: 44px; line-height: 1.1; font-weight: 700; }
.course-hero-corporate-ops { padding: 32px; border: 1px solid var(--border); background: var(--bg-elevated); }
.course-hero-corporate-ops .chapter-eyebrow-corporate-ops { display: block; margin-bottom: 8px; }
.course-hero-corporate-ops h1 { font-family: var(--font-display); font-size: 40px; margin: 0; }

/* terminal: shell prompt + markdown-style heading */
.chapter-hero-terminal, .course-hero-terminal { font-family: var(--font-mono); }
.prompt-terminal { color: var(--text-muted); }
.chapter-hero-terminal h1, .course-hero-terminal h1 {
  margin: 12px 0 0; font-family: var(--font-mono); font-size: 36px; line-height: 1.15; font-weight: 700; color: var(--accent);
}
.meta-terminal { margin-top: 8px; font-size: 13px; color: var(--text-muted); }

/* solarpunk: rounded card, sun decoration */
.chapter-hero-solarpunk, .course-hero-solarpunk {
  padding: 36px; border-radius: 28px; background: var(--bg-elevated); color: var(--accent-ink); position: relative; overflow: hidden;
}
.sun-decor { position: absolute; right: -40px; top: -60px; opacity: 0.25; }
.chapter-eyebrow-solarpunk { font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.12em; color: var(--secondary); }
.chapter-hero-solarpunk h1, .course-hero-solarpunk h1 {
  margin: 10px 0 0; font-family: var(--font-display); font-size: 46px; line-height: 1.05; font-weight: 800; max-width: 16ch; position: relative;
}

/* neon noir: clipped card, underline bar */
.chapter-hero-neon-noir, .course-hero-neon-noir {
  padding: 32px; background: var(--surface); border: 1px solid var(--border);
  clip-path: polygon(0 0, calc(100% - 32px) 0, 100% 32px, 100% 100%, 32px 100%, 0 calc(100% - 32px));
}
.chapter-eyebrow-neon-noir { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.16em; color: var(--accent); }
.chapter-hero-neon-noir h1, .course-hero-neon-noir h1 {
  margin: 10px 0 0; font-family: var(--font-display); font-size: 48px; line-height: 1.05; font-weight: 700; text-transform: uppercase; letter-spacing: 0.02em;
}
.underline-neon-noir { margin-top: 20px; height: 4px; width: 160px; background: var(--accent); }

/* ===== Objectives shortcode: 4 variants ===== */
.objectives-corporate-ops, .objectives-terminal, .objectives-solarpunk, .objectives-neon-noir { display: none; margin-top: 32px; }
:root[data-theme="corporate-ops"] .objectives-corporate-ops { display: grid; }
:root[data-theme="terminal"] .objectives-terminal { display: block; }
:root[data-theme="solarpunk"] .objectives-solarpunk { display: grid; }
:root[data-theme="neon-noir"] .objectives-neon-noir { display: grid; }

.objectives-corporate-ops { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1px; background: var(--border); border: 1px solid var(--border); }
.obj-cell-corporate-ops { background: var(--surface); padding: 20px; }
.obj-num-corporate-ops { font-family: var(--font-mono); font-size: 12px; color: var(--accent); }
.obj-cell-corporate-ops p { margin: 8px 0 0; font-size: 15px; line-height: 1.5; }

.objectives-terminal { padding: 20px 24px; border: 1px solid var(--border); font-family: var(--font-mono); font-size: 15px; line-height: 1.8; }
.obj-header-terminal { color: var(--text-muted); }
.obj-line-terminal { color: var(--text); }

.objectives-solarpunk { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.obj-card-solarpunk { background: var(--surface); border-radius: 18px; padding: 20px; }
.obj-numeral-solarpunk { font-family: var(--font-display); font-weight: 800; font-size: 28px; color: var(--tertiary); }
.obj-card-solarpunk p { margin: 6px 0 0; font-size: 16px; line-height: 1.5; }

.objectives-neon-noir { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.obj-card-neon-noir { padding: 18px; border: 1px solid var(--border); border-top: 2px solid var(--accent); }
.obj-num-neon-noir { font-family: var(--font-mono); font-size: 12px; color: var(--accent); }
.obj-card-neon-noir p { margin: 6px 0 0; font-size: 15px; line-height: 1.5; }

/* ===== Warning shortcode: 4 variants ===== */
.warn-corporate-ops, .warn-terminal, .warn-solarpunk, .warn-neon-noir { display: none; margin: 24px 0; }
:root[data-theme="corporate-ops"] .warn-corporate-ops,
:root[data-theme="solarpunk"] .warn-solarpunk,
:root[data-theme="neon-noir"] .warn-neon-noir { display: flex; }
:root[data-theme="terminal"] .warn-terminal { display: block; }

.warn-corporate-ops, .warn-solarpunk, .warn-neon-noir { gap: 16px; padding: 20px 24px; border-radius: var(--radius); }
.warn-corporate-ops { background: var(--warn-bg); border: 1px solid var(--warn-border); }
.warn-corporate-ops svg, .warn-neon-noir svg { stroke: var(--warn); flex: none; margin-top: 2px; }
.warn-corporate-ops .warn-title, .warn-neon-noir .warn-title { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.14em; color: var(--warn); font-weight: 600; }
.warn-corporate-ops p, .warn-neon-noir p, .warn-solarpunk p { margin: 6px 0 0; font-size: 16px; line-height: 1.6; }

.warn-terminal { padding: 16px 20px; border: 1px solid var(--warn); font-family: var(--font-mono); font-size: 15px; line-height: 1.6; }
.warn-terminal .warn-title { color: var(--warn); font-weight: 600; }
.warn-terminal .warn-body { margin-top: 6px; }

.warn-solarpunk { background: var(--warn-bg); }
.warn-solarpunk svg { stroke: var(--warn); flex: none; margin-top: 3px; }
.warn-solarpunk .warn-title { font-weight: 700; color: var(--warn); font-family: var(--font-body); }

.warn-neon-noir { background: var(--surface); border: 1px solid var(--warn); }
.warn-neon-noir .warn-title { font-family: var(--font-display); font-weight: 700; letter-spacing: 0.08em; }

/* ===== Course chapter list (course landing page) ===== */
.course-chapter-list { list-style: none; margin: 24px 0 0; padding: 0; display: flex; flex-direction: column; gap: 4px; }
.course-chapter-list a { display: flex; align-items: baseline; gap: 16px; padding: 14px 16px; color: var(--text); border: 1px solid var(--border); border-radius: var(--radius); }
.course-chapter-list a:hover { border-color: var(--accent); }
.course-chapter-list-num { font-family: var(--font-mono); color: var(--accent); font-size: 13px; }
.course-empty { color: var(--text-muted); margin-top: 24px; }

@media (max-width: 720px) {
  .objectives-corporate-ops, .objectives-solarpunk, .objectives-neon-noir { grid-template-columns: 1fr; }
  .chapter-num-corporate-ops { font-size: 64px; }
}