/* ==========================================================================
   ✨ PYTHON LERNPORTAL – CLEAN MODERN DESIGN SYSTEM ✨
   ========================================================================== */

:root {
  /* Brand Colors */
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-light: #eef2ff;
  --primary-glow: rgba(79, 70, 229, 0.15);

  --teal: #0d9488;
  --teal-light: #f0fdfa;

  --emerald: #059669;
  --emerald-light: #ecfdf5;

  --purple: #7c3aed;
  --purple-light: #f5f3ff;

  --amber: #d97706;
  --amber-light: #fffbeb;

  --rose: #e11d48;
  --rose-light: #fff1f2;

  /* Surfaces & Backgrounds */
  --bg-body: #f8fafc;
  --bg-surface: #ffffff;
  --bg-subtle: #f1f5f9;
  --bg-sidebar: #0f172a;
  --bg-code: #0b0f19;

  /* Borders */
  --border-color: #e2e8f0;
  --border-dark: rgba(255, 255, 255, 0.1);

  /* Typography */
  --text-main: #0f172a;
  --text-body: #334155;
  --text-muted: #64748b;
  --text-inverse: #f8fafc;

  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, Monaco, monospace;

  /* Elevation */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-body);
  color: var(--text-body);
  line-height: 1.65;
  font-size: 16px;
  display: flex;
  min-height: 100vh;
}

/* ==========================================================================
   LAYOUT: SIDEBAR (LEFT) + MAIN CONTENT (RIGHT)
   ========================================================================== */

.app-sidebar {
  width: 290px;
  min-width: 290px;
  height: 100vh;
  position: sticky;
  top: 0;
  background: var(--bg-sidebar);
  color: var(--text-inverse);
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border-dark);
  z-index: 100;
  overflow: hidden;
}

.sidebar-header {
  padding: 20px 18px;
  border-bottom: 1px solid var(--border-dark);
  display: flex;
  align-items: center;
  gap: 12px;
}

.sidebar-logo {
  font-size: 1.7rem;
  background: rgba(79, 70, 229, 0.2);
  border: 1px solid var(--primary);
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
}

.sidebar-title {
  font-size: 1.05rem;
  font-weight: 800;
  color: #ffffff;
  line-height: 1.2;
}

.sidebar-subtitle {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 14px 12px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.sidebar-nav::-webkit-scrollbar {
  width: 4px;
}

.sidebar-nav::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 2px;
}

.sidebar-group-title {
  font-size: 0.75rem;
  font-weight: 800;
  color: #94a3b8;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  padding: 4px 8px;
  margin-bottom: 4px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  color: #cbd5e1;
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 500;
  transition: all 0.15s ease;
  border-left: 3px solid transparent;
}

.sidebar-link:hover {
  background: rgba(255, 255, 255, 0.06);
  color: #ffffff;
}

.sidebar-link.active {
  background: rgba(79, 70, 229, 0.25);
  color: #ffffff;
  border-left-color: var(--primary);
  font-weight: 700;
}

.sidebar-link-icon {
  font-size: 1rem;
  flex-shrink: 0;
}

.sidebar-link-text {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-footer {
  padding: 14px 16px;
  border-top: 1px solid var(--border-dark);
  background: rgba(0, 0, 0, 0.2);
}

/* ==========================================================================
   MAIN CONTENT AREA
   ========================================================================== */

.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--bg-body);
}

header {
  background: linear-gradient(135deg, #090d16 0%, #1e1b4b 100%);
  color: white;
  padding: 35px 30px;
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.header-container {
  max-width: 900px;
  margin: 0 auto;
}

.header-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255, 255, 255, 0.12);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 10px;
  color: #c7d2fe;
}

header h1 {
  font-size: 2.1rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
  line-height: 1.2;
}

header p {
  font-size: 1.05rem;
  color: #94a3b8;
  line-height: 1.55;
}

/* Nav Links inside Header */
.nav-links {
  display: flex;
  gap: 8px;
  margin-bottom: 15px;
  font-size: 0.85rem;
  flex-wrap: wrap;
}

.nav-links a {
  color: #cbd5e1;
  text-decoration: none;
  background: rgba(255, 255, 255, 0.08);
  padding: 5px 12px;
  border-radius: var(--radius-full);
  transition: all 0.2s;
}

.nav-links a:hover {
  background: rgba(255, 255, 255, 0.2);
  color: white;
}

/* Main Content Container */
.container {
  max-width: 900px;
  width: 100%;
  margin: 30px auto;
  padding: 0 24px;
}

/* ==========================================================================
   CARDS & SECTIONS
   ========================================================================== */

.card {
  background: var(--bg-surface);
  border-radius: var(--radius-md);
  padding: 28px;
  margin-bottom: 24px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.card h2 {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
  border-bottom: 2px solid var(--bg-subtle);
  padding-bottom: 8px;
}

.card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 20px 0 10px 0;
  color: var(--text-main);
}

.card p {
  margin-bottom: 14px;
  color: var(--text-body);
}

/* Section Header */
.section-header {
  margin: 35px 0 15px 0;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px;
}

.section-header h2 {
  margin: 0;
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-main);
}

.section-desc {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin-top: 2px;
}

/* Track Badges */
.track-badge {
  display: inline-flex;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.track-1-badge { background: var(--emerald-light); color: var(--emerald); }
.track-2-badge { background: var(--primary-light); color: var(--primary); }
.track-3-badge { background: var(--purple-light); color: var(--purple); }

/* ==========================================================================
   ROADMAP MODULE CARDS (CLEAN & NON-NESTED)
   ========================================================================== */

.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 18px;
  margin: 20px 0 35px 0;
}

.roadmap-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.roadmap-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
}

.roadmap-number {
  font-size: 0.75rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  display: inline-flex;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  margin-bottom: 10px;
  align-self: flex-start;
}

.roadmap-title {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 6px;
  color: var(--text-main);
  line-height: 1.3;
}

.roadmap-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  flex: 1;
  line-height: 1.45;
}

.card-actions {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border-color);
}

.card-primary-btn {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: var(--primary);
  color: white;
  text-decoration: none;
  font-weight: 700;
  font-size: 0.88rem;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
}

.card-primary-btn:hover {
  background: var(--primary-hover);
}

.card-sublinks {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.card-sublinks a {
  flex: 1;
  text-align: center;
  background: var(--bg-subtle);
  color: var(--text-body);
  text-decoration: none;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 6px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  transition: all 0.15s ease;
}

.card-sublinks a:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* ==========================================================================
   BOXES, CODE & DIDACTICS
   ========================================================================== */

.box {
  border-radius: var(--radius-md);
  padding: 16px 20px;
  margin: 18px 0;
  border-left: 4px solid;
}

.box-title {
  font-weight: 800;
  font-size: 1rem;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.box-analogie { background: var(--purple-light); border-left-color: var(--purple); color: #4c1d95; }
.box-tipp { background: var(--primary-light); border-left-color: var(--primary); color: #312e81; }
.box-warning { background: var(--amber-light); border-left-color: var(--amber); color: #78350f; }
.box-danger { background: var(--rose-light); border-left-color: var(--rose); color: #881337; }
.box-success { background: var(--emerald-light); border-left-color: var(--emerald); color: #064e3b; }

/* Code Blocks */
.code-container {
  background: var(--bg-code);
  border-radius: var(--radius-md);
  margin: 18px 0;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-dark);
}

.code-header {
  background: #060911;
  color: #94a3b8;
  padding: 8px 14px;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

pre {
  margin: 0;
  padding: 16px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-inverse);
  line-height: 1.55;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--bg-subtle);
  color: #e11d48;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

pre code {
  background: transparent;
  color: inherit;
  padding: 0;
}

/* Syntax Highlighting */
.kw { color: #f472b6; font-weight: bold; }
.fn { color: #60a5fa; }
.str { color: #a7f3d0; }
.num { color: #fbbf24; }
.cm { color: #64748b; font-style: italic; }
.var { color: #cbd5e1; }
.attr { color: #38bdf8; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 18px;
  background: var(--primary);
  color: white;
  text-decoration: none;
  font-weight: 700;
  font-size: 0.9rem;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn:hover {
  background: var(--primary-hover);
}

.btn-secondary {
  background: var(--bg-surface);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-subtle);
}

.footer-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 35px;
  gap: 12px;
  flex-wrap: wrap;
}

/* Search Bar */
.search-bar-container {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 10px 16px;
  margin-bottom: 25px;
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: var(--shadow-sm);
}

.search-input {
  flex: 1;
  border: none;
  outline: none;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  color: var(--text-main);
  background: transparent;
}

/* Mobile Toggle */
.sidebar-mobile-toggle {
  display: none;
  position: fixed;
  bottom: 20px;
  left: 20px;
  z-index: 1000;
  background: var(--primary);
  color: white;
  border: none;
  padding: 10px 18px;
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 800;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.6);
  z-index: 99;
}

/* Responsive Breakpoints */
@media (max-width: 900px) {
  body {
    flex-direction: column;
  }

  .app-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    box-shadow: var(--shadow-xl);
  }

  .app-sidebar.open {
    transform: translateX(0);
  }

  .sidebar-mobile-toggle {
    display: block;
  }

  .sidebar-overlay.active {
    display: block;
  }

  .container {
    padding: 0 16px;
  }

  header h1 {
    font-size: 1.7rem;
  }
}