/* ========================================================================
   ITADM Academy - Terminal Design
   ======================================================================== */

@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600;700;800&family=Outfit:wght@300;400;500;600;700;800&display=swap');

:root {
  --bg-deep: #0a0e14;
  --bg-darker: #0d1117;
  --bg-dark: #161b22;
  --bg-medium: #1c2128;
  --bg-light: #21262d;
  --bg-hover: #30363d;

  --border-subtle: #21262d;
  --border-default: #30363d;
  --border-emphasis: #6e7681;

  --text-primary: #c9d1d9;
  --text-secondary: #8b949e;
  --text-muted: #6e7681;
  --text-faint: #484f58;

  --accent: #39ff14;
  --accent-dim: #2ecc40;
  --accent-glow: rgba(57, 255, 20, 0.3);
  --accent-soft: rgba(57, 255, 20, 0.08);

  --color-info: #58a6ff;
  --color-warn: #f0b72f;
  --color-error: #ff6b6b;
  --color-success: #39ff14;
  --color-purple: #bc8cff;
  --color-orange: #ffa657;

  --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
  --font-sans: 'Outfit', system-ui, -apple-system, sans-serif;

  --radius-sm: 4px;
  --radius: 8px;
  --radius-lg: 12px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-deep);
  color: var(--text-primary);
  line-height: 1.65;
  min-height: 100vh;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(57, 255, 20, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(57, 255, 20, 0.025) 1px, transparent 1px);
  background-size: 50px 50px;
  pointer-events: none;
  z-index: 0;
}

body::after {
  content: '';
  position: fixed;
  inset: 0;
  background: radial-gradient(ellipse at top, rgba(57, 255, 20, 0.04), transparent 60%);
  pointer-events: none;
  z-index: 0;
}

/* ========================================================================
   HEADER / NAVIGATION
   ======================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 14, 20, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
}

.nav-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
}

.brand-prompt { color: var(--accent); font-weight: 800; }
.brand-name { color: var(--text-primary); }

.brand-cursor {
  display: inline-block;
  width: 0.55em;
  height: 1em;
  background: var(--accent);
  vertical-align: text-bottom;
  margin-left: 2px;
  animation: blink 1.1s steps(2) infinite;
}

@keyframes blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}

.nav-links {
  display: flex;
  gap: 0.25rem;
  list-style: none;
  flex-wrap: wrap;
}

.nav-links a {
  display: block;
  padding: 0.5rem 1rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
  position: relative;
}

.nav-links a:hover {
  color: var(--accent);
  background: var(--accent-soft);
}

.nav-links a.active {
  color: var(--accent);
  background: var(--accent-soft);
}

.nav-links a.active::before {
  content: '> ';
  color: var(--accent);
}

.nav-links a.disabled {
  color: var(--text-faint);
  cursor: not-allowed;
  pointer-events: none;
}

.nav-links a.disabled::after {
  content: ' [soon]';
  font-size: 0.7em;
  color: var(--text-faint);
}

/* ========================================================================
   MAIN CONTAINER
   ======================================================================== */

.main-container {
  position: relative;
  z-index: 1;
  max-width: 1400px;
  margin: 0 auto;
  padding: 2rem;
}

.page-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 3rem;
  align-items: start;
}

@media (max-width: 1024px) {
  .page-layout { grid-template-columns: 1fr; }
}

/* ========================================================================
   SIDEBAR
   ======================================================================== */

.sidebar {
  position: sticky;
  top: 5rem;
  max-height: calc(100vh - 7rem);
  overflow-y: auto;
  padding: 1.5rem;
  background: var(--bg-darker);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

@media (max-width: 1024px) {
  .sidebar { position: relative; top: 0; max-height: none; }
}

.sidebar-title {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--text-muted);
  margin-bottom: 1rem;
  font-weight: 600;
}

.sidebar-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.sidebar-list a {
  display: block;
  padding: 0.45rem 0.75rem;
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
  transition: all 0.15s ease;
  font-size: 0.83rem;
}

.sidebar-list a:hover {
  color: var(--accent);
  background: var(--accent-soft);
  border-left-color: var(--accent);
}

.sidebar-list a.block-link {
  font-weight: 600;
  color: var(--text-primary);
}

.sidebar-list a.lab-link {
  padding-left: 1.5rem;
  font-size: 0.78rem;
  color: var(--color-orange);
}

.sidebar-divider {
  height: 1px;
  background: var(--border-subtle);
  margin: 0.75rem 0;
}

/* ========================================================================
   PAGE HEADER (HERO)
   ======================================================================== */

.page-hero {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-subtle);
}

.page-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.page-eyebrow::before {
  content: '$';
  font-weight: 700;
}

.page-title {
  font-family: var(--font-sans);
  font-size: clamp(2rem, 4vw, 3.5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.page-title .highlight { color: var(--accent); }

.page-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 65ch;
}

.page-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

.meta-item {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.7rem;
  background: var(--bg-dark);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
}

.meta-item-icon { color: var(--accent); }

/* ========================================================================
   TIME BLOCKS
   ======================================================================== */

.timeblock {
  margin-bottom: 4rem;
  scroll-margin-top: 5rem;
}

.timeblock-header {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--accent);
  flex-wrap: wrap;
}

.timeblock-time {
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--accent);
  font-weight: 700;
}

.timeblock-title {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  flex: 1;
}

.timeblock-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  border-radius: 100px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-vortrag {
  background: rgba(88, 166, 255, 0.15);
  color: var(--color-info);
  border: 1px solid rgba(88, 166, 255, 0.3);
}

.badge-action {
  background: rgba(57, 255, 20, 0.12);
  color: var(--accent);
  border: 1px solid rgba(57, 255, 20, 0.3);
}

.badge-lab {
  background: rgba(255, 166, 87, 0.12);
  color: var(--color-orange);
  border: 1px solid rgba(255, 166, 87, 0.3);
}

.badge-quiz {
  background: rgba(188, 140, 255, 0.12);
  color: var(--color-purple);
  border: 1px solid rgba(188, 140, 255, 0.3);
}

/* ========================================================================
   SUB-BLOCKS
   ======================================================================== */

.subblock { margin-bottom: 2.5rem; }

.subblock-header {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.subblock-time {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

.subblock-title {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-primary);
}

.subblock h4 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 1.5rem 0 0.75rem;
}

.subblock p {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.subblock ul, .subblock ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.subblock li {
  margin-bottom: 0.4rem;
  color: var(--text-primary);
}

.subblock li::marker { color: var(--accent); }

/* ========================================================================
   CODE BLOCKS
   ======================================================================== */

.code-block {
  position: relative;
  margin: 1.5rem 0;
  background: var(--bg-darker);
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  overflow: hidden;
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 1rem;
  background: var(--bg-dark);
  border-bottom: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.code-header-dots { display: flex; gap: 0.4rem; }

.code-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.code-dot-red { background: #ff5f56; }
.code-dot-yellow { background: #ffbd2e; }
.code-dot-green { background: #27c93f; }

.code-lang {
  color: var(--text-muted);
  font-weight: 500;
}

.copy-btn {
  background: transparent;
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
  padding: 0.3rem 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s ease;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-weight: 600;
}

.copy-btn:hover {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
}

.copy-btn.copied {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
}

.code-block pre {
  padding: 1.25rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-primary);
}

.code-block pre code {
  font-family: inherit;
  background: none;
  padding: 0;
  color: inherit;
}

p code, li code, td code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--bg-dark);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  color: var(--accent);
  border: 1px solid var(--border-subtle);
}

/* ========================================================================
   CALLOUTS
   ======================================================================== */

.callout {
  margin: 1.5rem 0;
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius);
  border-left: 4px solid;
  background: var(--bg-dark);
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.callout-icon { font-size: 1.4rem; flex-shrink: 0; line-height: 1; }
.callout-content { flex: 1; }

.callout-title {
  font-weight: 700;
  margin-bottom: 0.25rem;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.callout-tip {
  border-left-color: var(--accent);
  background: rgba(57, 255, 20, 0.05);
}
.callout-tip .callout-title { color: var(--accent); }

.callout-warn {
  border-left-color: var(--color-warn);
  background: rgba(240, 183, 47, 0.07);
}
.callout-warn .callout-title { color: var(--color-warn); }

.callout-danger {
  border-left-color: var(--color-error);
  background: rgba(255, 107, 107, 0.08);
}
.callout-danger .callout-title { color: var(--color-error); }

.callout-info {
  border-left-color: var(--color-info);
  background: rgba(88, 166, 255, 0.07);
}
.callout-info .callout-title { color: var(--color-info); }

.callout-trainer {
  border-left-color: var(--color-purple);
  background: rgba(188, 140, 255, 0.07);
  font-family: var(--font-mono);
  font-size: 0.92rem;
}
.callout-trainer .callout-title { color: var(--color-purple); }

/* ========================================================================
   LAB CARDS
   ======================================================================== */

.lab {
  margin: 2rem 0;
  background: linear-gradient(180deg, rgba(255, 166, 87, 0.04) 0%, transparent 100%);
  border: 1px solid rgba(255, 166, 87, 0.3);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.lab-header {
  padding: 1.25rem 1.5rem;
  background: rgba(255, 166, 87, 0.08);
  border-bottom: 1px solid rgba(255, 166, 87, 0.2);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.lab-icon { font-size: 1.5rem; }

.lab-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-orange);
  font-weight: 700;
}

.lab-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-left: auto;
}

.lab-duration {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  padding: 0.25rem 0.6rem;
  border: 1px solid var(--border-subtle);
  border-radius: 100px;
}

.lab-body { padding: 1.5rem; }

.lab-scenario {
  font-style: italic;
  color: var(--text-secondary);
  padding: 1rem;
  background: var(--bg-darker);
  border-left: 3px solid var(--color-orange);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.92rem;
}

.lab-section-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--color-orange);
  margin: 1.5rem 0 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.lab-section-title::before {
  content: '▸';
  color: var(--color-orange);
}

.lab-tasks { padding-left: 1.5rem; }

.lab-tasks li {
  margin-bottom: 0.5rem;
  padding-left: 0.25rem;
}

/* ========================================================================
   SOLUTION (Lösung)
   ======================================================================== */

.solution {
  margin: 1rem 0;
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-darker);
}

.solution-toggle {
  width: 100%;
  padding: 0.85rem 1.25rem;
  background: var(--bg-dark);
  border: none;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: background 0.15s ease;
}

.solution-toggle:hover { background: var(--bg-medium); }

.solution-toggle::before { content: '🔓 '; margin-right: 0.4rem; }

.solution-toggle .toggle-arrow {
  transition: transform 0.2s ease;
  font-size: 0.7rem;
}

.solution.open .toggle-arrow { transform: rotate(180deg); }

.solution-content {
  display: none;
  padding: 1.25rem;
  border-top: 1px solid var(--border-subtle);
}

.solution.open .solution-content {
  display: block;
  animation: slideDown 0.25s ease;
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ========================================================================
   QUIZ
   ======================================================================== */

.quiz-container { margin: 2rem 0; }

.quiz-card {
  margin-bottom: 1rem;
  padding: 1.5rem;
  background: var(--bg-dark);
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  transition: border-color 0.2s ease;
}

.quiz-card.answered { border-color: var(--accent); }

.quiz-question {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.quiz-question-number {
  color: var(--accent);
  font-family: var(--font-mono);
  margin-right: 0.5rem;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.quiz-option {
  padding: 0.65rem 1rem;
  background: var(--bg-darker);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-primary);
  text-align: left;
  transition: all 0.15s ease;
}

.quiz-option:hover {
  background: var(--bg-medium);
  border-color: var(--border-emphasis);
}

.quiz-option.correct {
  background: rgba(57, 255, 20, 0.15);
  border-color: var(--accent);
  color: var(--accent);
}

.quiz-option.wrong {
  background: rgba(255, 107, 107, 0.15);
  border-color: var(--color-error);
  color: var(--color-error);
}

.quiz-feedback {
  margin-top: 1rem;
  padding: 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  display: none;
}

.quiz-feedback.show { display: block; }

.quiz-feedback.correct {
  background: rgba(57, 255, 20, 0.1);
  color: var(--accent);
}

.quiz-feedback.wrong {
  background: rgba(255, 107, 107, 0.1);
  color: var(--color-error);
}

/* ========================================================================
   TABLES
   ======================================================================== */

.table-wrapper {
  margin: 1.5rem 0;
  overflow-x: auto;
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

thead { background: var(--bg-dark); }

th {
  padding: 0.85rem 1rem;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  border-bottom: 2px solid var(--accent);
}

td {
  padding: 0.7rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-primary);
}

tbody tr:last-child td { border-bottom: none; }
tbody tr:hover { background: var(--bg-darker); }

/* ========================================================================
   ASCII / DIAGRAM BLOCKS
   ======================================================================== */

.ascii-box {
  margin: 1.5rem 0;
  padding: 1.5rem;
  background: var(--bg-darker);
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--accent);
  white-space: pre;
  overflow-x: auto;
}

/* ========================================================================
   HERO (Startseite)
   ======================================================================== */

.hero {
  padding: 5rem 0 4rem;
  text-align: center;
  position: relative;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  background: var(--accent-soft);
  border: 1px solid var(--accent);
  border-radius: 100px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  margin-bottom: 1.5rem;
  font-weight: 600;
}

.hero-eyebrow::before {
  content: '●';
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 5rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.04em;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

.hero-title .hero-highlight {
  color: var(--accent);
  position: relative;
  display: inline-block;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 60ch;
  margin: 0 auto 2.5rem;
  line-height: 1.5;
}

.hero-terminal {
  max-width: 720px;
  margin: 2rem auto;
  background: var(--bg-darker);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  overflow: hidden;
  text-align: left;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5), 0 0 80px rgba(57, 255, 20, 0.05);
}

.hero-terminal-header {
  padding: 0.75rem 1rem;
  background: var(--bg-dark);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.hero-terminal-title {
  margin-left: auto;
  margin-right: auto;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.hero-terminal-body {
  padding: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  line-height: 1.8;
}

.hero-terminal-body .line { display: block; }
.hero-terminal-body .prompt { color: var(--accent); font-weight: 700; }
.hero-terminal-body .output { color: var(--text-secondary); }

/* ========================================================================
   MODULE CARDS (Startseite)
   ======================================================================== */

.module-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin: 4rem 0;
}

.module-card {
  position: relative;
  padding: 2rem;
  background: var(--bg-darker);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: inherit;
  transition: all 0.25s ease;
  overflow: hidden;
}

.module-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 0%, var(--accent-soft) 100%);
  opacity: 0;
  transition: opacity 0.25s ease;
}

.module-card:not(.locked):hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3), 0 0 30px rgba(57, 255, 20, 0.1);
}

.module-card:not(.locked):hover::before { opacity: 1; }

.module-card-content { position: relative; z-index: 1; }

.module-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  display: block;
}

.module-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.5rem;
  display: inline-block;
  padding: 0.2rem 0.5rem;
  background: var(--accent-soft);
  border-radius: 100px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.module-card-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.module-card-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}

.module-card-topics {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.module-card-topics li {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  background: var(--bg-dark);
  border: 1px solid var(--border-subtle);
  border-radius: 100px;
  color: var(--text-secondary);
}

.module-card-arrow {
  position: absolute;
  bottom: 1.5rem;
  right: 1.5rem;
  font-size: 1.5rem;
  color: var(--accent);
  opacity: 0;
  transform: translateX(-10px);
  transition: all 0.25s ease;
}

.module-card:hover .module-card-arrow {
  opacity: 1;
  transform: translateX(0);
}

.module-card.locked {
  opacity: 0.6;
  cursor: not-allowed;
}

.module-card.locked::after {
  content: '🔒 Coming Soon';
  position: absolute;
  top: 1rem;
  right: 1rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  background: var(--bg-dark);
  padding: 0.3rem 0.6rem;
  border-radius: 100px;
  border: 1px solid var(--border-subtle);
}

/* ========================================================================
   DAY CARDS (Linux Übersicht)
   ======================================================================== */

.day-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin: 3rem 0;
}

.day-card {
  position: relative;
  padding: 2rem;
  background: var(--bg-darker);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: inherit;
  transition: all 0.25s ease;
  overflow: hidden;
}

.day-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 0%, var(--accent-soft) 100%);
  opacity: 0;
  transition: opacity 0.25s ease;
}

.day-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3), 0 0 30px rgba(57, 255, 20, 0.1);
}

.day-card:hover::before { opacity: 1; }

.day-card-content { position: relative; z-index: 1; }

.day-number {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.day-card-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.day-card-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}

.day-card-topics {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.day-card-topics li {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  background: var(--bg-dark);
  border: 1px solid var(--border-subtle);
  border-radius: 100px;
  color: var(--text-secondary);
}

.day-card-arrow {
  position: absolute;
  bottom: 1.5rem;
  right: 1.5rem;
  font-size: 1.5rem;
  color: var(--accent);
  opacity: 0;
  transform: translateX(-10px);
  transition: all 0.25s ease;
}

.day-card:hover .day-card-arrow {
  opacity: 1;
  transform: translateX(0);
}

.day-card.day-locked {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

.day-card.day-locked::after {
  content: '🔒 Bald verfügbar';
  position: absolute;
  top: 1rem;
  right: 1rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
}

/* ========================================================================
   FEATURE CARDS
   ======================================================================== */

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.feature-card {
  padding: 1.5rem;
  background: var(--bg-darker);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
}

.feature-card-icon {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.feature-card h3 {
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ========================================================================
   SECTION TITLES
   ======================================================================== */

.section-title {
  font-size: 2rem;
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
  font-weight: 800;
}

.section-subtitle {
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 60ch;
}

/* ========================================================================
   FOOTER
   ======================================================================== */

.site-footer {
  margin-top: 5rem;
  padding: 2.5rem 2rem;
  border-top: 1px solid var(--border-subtle);
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  position: relative;
  z-index: 1;
}

.footer-main {
  font-size: 0.9rem;
  margin-bottom: 0.4rem;
  color: var(--text-secondary);
}

.footer-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer-powered {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.78rem;
  color: var(--text-muted);
}

.footer-powered a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}

.footer-powered a:hover {
  text-decoration: underline;
}

/* ========================================================================
   UTILS
   ======================================================================== */

strong {
  color: var(--accent);
  font-weight: 600;
}

em { color: var(--text-secondary); }

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover { text-decoration: underline; }

hr {
  border: none;
  border-top: 1px solid var(--border-subtle);
  margin: 2rem 0;
}

::selection {
  background: var(--accent);
  color: var(--bg-deep);
}

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg-darker); }
::-webkit-scrollbar-thumb {
  background: var(--bg-light);
  border-radius: 100px;
  border: 2px solid var(--bg-darker);
}
::-webkit-scrollbar-thumb:hover { background: var(--bg-hover); }

/* Mobile */
@media (max-width: 768px) {
  .nav-container { padding: 1rem; }
  .nav-links { gap: 0; }
  .nav-links a { padding: 0.4rem 0.6rem; font-size: 0.8rem; }
  .main-container { padding: 1rem; }
  .lab-header { flex-direction: column; align-items: flex-start; }
  .lab-title { margin-left: 0; }
}

/* Print */
@media print {
  body::before, body::after { display: none; }
  .site-header, .sidebar, .copy-btn, .solution-toggle, .quiz-options { display: none; }
  .solution-content { display: block !important; }
  body { background: white; color: black; }
  .code-block { border: 1px solid #ccc; background: #f6f8fa; }
  .code-block pre, .code-block pre code { color: #000; }
}

/* ========================================================================
   CHAPTER NAVIGATION (zurück / weiter zwischen Kapitelseiten)
   ======================================================================== */

.chapter-nav {
  display: flex;
  justify-content: space-between;
  align-items: stretch;
  gap: 1rem;
  margin: 3rem 0 1rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
}

.chapter-nav a {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 1rem 1.25rem;
  background: var(--bg-dark);
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  color: var(--text-primary);
  text-decoration: none;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.chapter-nav a:hover {
  border-color: var(--accent);
  background: var(--bg-medium);
  text-decoration: none;
}

.chapter-nav .nav-eyebrow {
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.25rem;
}

.chapter-nav .nav-title {
  font-weight: 600;
  color: var(--accent);
}

.chapter-nav .nav-next { text-align: right; }

.chapter-nav .nav-spacer {
  flex: 1;
  visibility: hidden;
}

/* ========================================================================
   CHAPTER GRID (Kachel-Übersicht auf der Tag-Indexseite)
   ======================================================================== */

.chapter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
  margin: 2rem 0;
}

.chapter-card {
  display: block;
  padding: 1.25rem;
  background: var(--bg-dark);
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text-primary);
  font-family: var(--font-sans);
  transition: border-color 0.15s ease, transform 0.15s ease, background 0.15s ease;
  position: relative;
}

.chapter-card:hover {
  border-color: var(--accent);
  background: var(--bg-medium);
  transform: translateY(-2px);
  text-decoration: none;
}

.chapter-card-number {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  margin-bottom: 0.4rem;
}

.chapter-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
  color: var(--text-primary);
}

.chapter-card-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.chapter-card-badge {
  display: inline-block;
  margin-top: 0.6rem;
  padding: 0.15rem 0.5rem;
  background: var(--accent-soft);
  border: 1px solid var(--accent-dim);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
}

/* ========================================================================
   SCHEDULE LIST (Tagesplan auf der Tag-Indexseite)
   ======================================================================== */

.schedule-list {
  list-style: none;
  padding: 0;
  margin: 1.5rem 0;
}

.schedule-list li {
  display: flex;
  gap: 1rem;
  align-items: baseline;
  padding: 0.6rem 0;
  border-bottom: 1px dashed var(--border-subtle);
}

.schedule-list li:last-child { border-bottom: none; }

.schedule-time {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  flex-shrink: 0;
  width: 7.5rem;
}

.schedule-label {
  color: var(--text-primary);
}

.schedule-label small {
  display: block;
  color: var(--text-muted);
  font-size: 0.8rem;
  margin-top: 0.1rem;
}

@media (max-width: 600px) {
  .chapter-nav { flex-direction: column; }
  .chapter-nav .nav-next { text-align: left; }
  .schedule-list li { flex-direction: column; gap: 0.2rem; }
  .schedule-time { width: auto; }
}