/* ============================================================
   BITC University — Dark Cyberpunk Theme
   ============================================================ */

/* ===== CSS CUSTOM PROPERTIES ===== */
:root {
  --bg:          #090e1a;
  --bg-sidebar:  #0b1120;
  --bg-card:     #0f1829;
  --border:      #1a2744;
  --text:        #c9d8f0;
  --text-hd:     #e8f4ff;
  --text-muted:  #6b85a8;
  --cyan:        #c4d4ec;
  --cyan-dim:    rgba(196,212,236,0.35);
  --cyan-faint:  rgba(196,212,236,0.08);
  --glow-sm:     0 0 12px rgba(196,212,236,0.28);
  --glow-md:     0 0 24px rgba(196,212,236,0.28), 0 0 48px rgba(196,212,236,0.12);
  --fast:        150ms cubic-bezier(0.4,0,0.2,1);
  --base:        300ms cubic-bezier(0.4,0,0.2,1);
  --slow:        600ms cubic-bezier(0,0,0.2,1);
  --sidebar-w:   280px;
  --topbar-h:    52px;
  --sans:        "Inter", system-ui, sans-serif;
  --display:     "Space Grotesk", "Inter", sans-serif;
  --mono:        "JetBrains Mono", monospace;
}

html[data-theme="light"] {
  --bg:         #f4f6fb;
  --bg-sidebar: #eef1f7;
  --bg-card:    #ffffff;
  --border:     #d1d9e6;
  --text:       #2d3748;
  --text-hd:    #1a202c;
  --text-muted: #718096;
  --cyan:       #6a7f9a;
  --cyan-dim:   rgba(106,127,154,0.25);
  --cyan-faint: rgba(106,127,154,0.08);
  --glow-sm:    0 0 8px rgba(106,127,154,0.2);
  --glow-md:    0 0 16px rgba(106,127,154,0.25);
}

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

html {
  scroll-behavior: smooth;
  background-color: #0a0e1b;
  /* Visible grain texture via SVG feTurbulence noise */
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.72' numOctaves='4' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)' opacity='0.22'/%3E%3C/svg%3E"),
    /* Large weathered smudge patches */
    radial-gradient(ellipse 900px 700px at 15% 25%, rgba(120,130,150,0.18) 0%, transparent 50%),
    radial-gradient(ellipse 800px 600px at 85% 75%, rgba(90,100,130,0.14) 0%, transparent 50%),
    /* Diagonal scratch marks */
    linear-gradient(118deg, transparent 22%, rgba(255,255,255,0.06) 23%, rgba(255,255,255,0.06) 24%, transparent 25%),
    linear-gradient(43deg,  transparent 18%, rgba(255,255,255,0.04) 19%, rgba(255,255,255,0.04) 20%, transparent 21%);
  background-size:
    300px 300px,
    100% 100%,
    100% 100%,
    cover,
    cover;
  background-attachment: fixed;
}

html[data-theme="light"] {
  background-color: #f4f6fb;
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.72' numOctaves='4' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)' opacity='0.07'/%3E%3C/svg%3E"),
    radial-gradient(ellipse 900px 700px at 15% 25%, rgba(180,185,200,0.1) 0%, transparent 50%),
    radial-gradient(ellipse 800px 600px at 85% 75%, rgba(160,165,185,0.08) 0%, transparent 50%);
  background-size:
    300px 300px,
    100% 100%,
    100% 100%;
  background-attachment: fixed;
}

body {
  font-family: var(--sans);
  background: transparent;
  color: var(--text);
  font-size: 16px;
  line-height: 1.75;
  transition: color var(--base);
  min-height: 100vh;
}

/* ===== LAYOUT ===== */
.site-wrapper {
  display: flex;
  min-height: 100vh;
}

/* ===== SIDEBAR ===== */
.sidebar {
  width: var(--sidebar-w);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; left: 0; bottom: 0;
  z-index: 100;
  overflow-y: auto;
  overflow-x: hidden;
  transition: transform var(--base), background var(--base);
}

.sidebar-header {
  padding: 1.25rem;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, #0c1325 0%, var(--bg-sidebar) 100%);
  flex-shrink: 0;
}
html[data-theme="light"] .sidebar-header {
  background: linear-gradient(180deg, #e4eaf6 0%, var(--bg-sidebar) 100%);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  font-family: var(--display);
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  /* Gradient silver → white text */
  background: linear-gradient(135deg, #8ca0bc 0%, #c8d6eb 40%, #eef3fb 75%, #ffffff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  transition: filter var(--base);
}
.brand:hover { filter: brightness(1.15); }
html[data-theme="light"] .brand {
  background: linear-gradient(135deg, #4a5e78 0%, #6a7f9a 50%, #8a9fb8 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.brand-eq {
  font-size: 0.45rem;
  letter-spacing: 1px;
  opacity: 0.8;
  display: inline-block;
  line-height: 1;
  animation: eq-pulse 1.4s ease-in-out infinite alternate;
}

@keyframes eq-pulse {
  0%   { letter-spacing: 0.5px; opacity: 0.4; transform: scaleY(0.6); }
  50%  { letter-spacing: 2px;   opacity: 1;   transform: scaleY(1.3); }
  100% { letter-spacing: 1px;   opacity: 0.7; transform: scaleY(1); }
}

.sidebar-nav {
  flex: 1;
  padding: 0.5rem 0 1rem;
  overflow-y: auto;
}

.nav-section-label {
  font-family: var(--display);
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding: 1rem 1.25rem 0.3rem;
  user-select: none;
}

.nav-link {
  display: block;
  padding: 0.38rem 1.25rem 0.38rem 1.5rem;
  font-size: 0.875rem;
  color: var(--text);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: background var(--fast), color var(--fast), border-color var(--fast);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.nav-link:hover {
  background: var(--cyan-faint);
  border-left-color: var(--cyan);
  color: var(--text-hd);
}
.nav-link.active {
  background: linear-gradient(90deg, rgba(196,212,236,0.12) 0%, transparent 100%);
  border-left-color: var(--cyan);
  color: var(--cyan);
  font-weight: 600;
}
html[data-theme="light"] .nav-link.active {
  background: linear-gradient(90deg, rgba(106,127,154,0.1) 0%, transparent 100%);
}
.nav-link.external {
  color: var(--text-muted);
  font-size: 0.82rem;
}
.nav-link.external:hover { color: var(--cyan); }

.sidebar-footer {
  border-top: 1px solid var(--border);
  padding: 1rem;
  display: flex;
  justify-content: center;
  flex-shrink: 0;
}
.sidebar-watermark {
  width: 65%;
  max-width: 130px;
  opacity: 0.06;
  filter: grayscale(1);
  pointer-events: none;
  display: block;
}

/* ===== MAIN WRAP ===== */
.main-wrap {
  flex: 1;
  margin-left: var(--sidebar-w);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* ===== TOP BAR ===== */
.top-bar {
  height: var(--topbar-h);
  background: var(--bg-sidebar);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 1.25rem;
  gap: 1rem;
  position: sticky;
  top: 0;
  z-index: 50;
  background-size: 200% 100%;
  background-image: linear-gradient(90deg, var(--bg-sidebar) 0%, #0d1a2e 50%, var(--bg-sidebar) 100%);
  animation: shimmer 8s ease-in-out infinite alternate;
  transition: background-color var(--base);
}
html[data-theme="light"] .top-bar {
  animation: none;
  background-image: none;
}

@keyframes shimmer {
  0%   { background-position: 0% 50%; }
  100% { background-position: 100% 50%; }
}

.top-bar-title {
  flex: 1;
  font-family: var(--display);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  text-decoration: none;
  display: none;
  background: linear-gradient(135deg, #8ca0bc 0%, #c8d6eb 40%, #eef3fb 75%, #ffffff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
html[data-theme="light"] .top-bar-title {
  background: linear-gradient(135deg, #4a5e78 0%, #6a7f9a 50%, #8a9fb8 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.menu-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  flex-shrink: 0;
}
.menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--cyan);
  border-radius: 2px;
  transition: var(--fast);
}

.theme-btn {
  margin-left: auto;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.3rem 0.75rem;
  cursor: pointer;
  font-size: 1rem;
  line-height: 1;
  color: var(--text);
  transition: background var(--fast), border-color var(--fast), box-shadow var(--fast);
  flex-shrink: 0;
}
.theme-btn:hover {
  background: var(--cyan-faint);
  border-color: var(--cyan);
  box-shadow: var(--glow-sm);
}
.icon-light { display: none; }
html[data-theme="light"] .icon-dark  { display: none; }
html[data-theme="light"] .icon-light { display: inline; }

/* ===== PAGE CONTENT ===== */
.page-content {
  max-width: 900px;
  width: 100%;
  margin: 0 auto;
  padding: 2.5rem 2rem 4rem;
  animation: fade-up var(--slow) both;
}

@keyframes fade-up {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ===== TYPOGRAPHY ===== */
.page-content h1 {
  font-family: var(--display);
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 700;
  color: var(--text-hd);
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  padding-bottom: 0.6rem;
  position: relative;
}
.page-content h1::after {
  content: "";
  position: absolute;
  bottom: 0; left: 0;
  width: 3rem; height: 2px;
  background: linear-gradient(90deg, var(--cyan), transparent);
  box-shadow: var(--glow-sm);
}

.page-content h2 {
  font-family: var(--display);
  font-size: clamp(1.2rem, 3vw, 1.6rem);
  font-weight: 700;
  color: var(--text-hd);
  letter-spacing: -0.01em;
  line-height: 1.3;
  margin: 2.5rem 0 0.75rem;
}

.page-content h3 {
  font-family: var(--sans);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-hd);
  margin: 2rem 0 0.5rem;
}

.page-content h4, .page-content h5, .page-content h6 {
  font-family: var(--sans);
  font-weight: 600;
  color: var(--text-hd);
  margin: 1.5rem 0 0.4rem;
}

.page-content p { margin-bottom: 1rem; }

.page-content strong { color: var(--text-hd); font-weight: 600; }

.page-content em { color: var(--text-muted); }

.page-content a {
  color: var(--cyan);
  text-decoration: underline;
  text-decoration-color: var(--cyan-dim);
  text-underline-offset: 3px;
  transition: color var(--fast), text-decoration-color var(--fast);
}
.page-content a:hover {
  color: var(--text-hd);
  text-decoration-color: transparent;
}

/* ===== HR ===== */
.page-content hr {
  border: none;
  height: 1px;
  background: linear-gradient(90deg,
    transparent 0%, var(--cyan) 20%,
    rgba(196,212,236,0.4) 50%,
    var(--cyan) 80%, transparent 100%);
  margin: 2.5rem 0;
  animation: hr-pulse 3s ease-in-out infinite;
}
html[data-theme="light"] .page-content hr { animation: none; }

@keyframes hr-pulse {
  0%, 100% { opacity: 0.5; }
  50%       { opacity: 1; box-shadow: 0 0 14px var(--cyan-dim); }
}

/* ===== LISTS ===== */
.page-content ul,
.page-content ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}
.page-content li { margin-bottom: 0.3rem; }
.page-content li > ul,
.page-content li > ol { margin-top: 0.3rem; margin-bottom: 0; }

/* ===== BLOCKQUOTE ===== */
.page-content blockquote {
  border-left: 3px solid var(--cyan);
  padding: 0.75rem 1.25rem;
  margin: 1.5rem 0;
  background: var(--cyan-faint);
  border-radius: 0 8px 8px 0;
  color: var(--text-muted);
}
.page-content blockquote p { margin-bottom: 0; }

/* ===== TABLES ===== */
.page-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 24px rgba(0,0,0,0.3);
  font-size: 0.9rem;
}
.page-content th {
  background: linear-gradient(90deg, #0f1d35, #111e38);
  color: var(--cyan);
  font-family: var(--display);
  font-weight: 600;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--cyan);
}
html[data-theme="light"] .page-content th {
  background: linear-gradient(90deg, #dde6f5, #e6edf8);
}
.page-content td {
  padding: 0.6rem 1rem;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  vertical-align: top;
}
.page-content tr:last-child td { border-bottom: none; }
.page-content tr:nth-child(even) td { background: rgba(255,255,255,0.018); }
.page-content tr { transition: background var(--fast); }
.page-content tbody tr:hover td { background: var(--cyan-faint); }

/* ===== CODE ===== */
.page-content code {
  font-family: var(--mono);
  font-size: 0.84em;
  background: var(--cyan-faint);
  color: var(--cyan);
  padding: 0.15em 0.45em;
  border-radius: 4px;
  border: 1px solid rgba(196,212,236,0.18);
}
.page-content pre {
  background: #0d1117;
  border: 1px solid rgba(196,212,236,0.18);
  border-top-color: rgba(196,212,236,0.4);
  border-radius: 8px;
  padding: 1.25rem 1.5rem;
  overflow-x: auto;
  margin: 1.25rem 0;
  box-shadow: 0 4px 20px rgba(0,0,0,0.5);
}
.page-content pre code {
  background: none;
  border: none;
  padding: 0;
  color: var(--text);
  font-size: 0.875rem;
  line-height: 1.6;
}

/* ===== IMAGES ===== */
.page-content img {
  max-width: 100%;
  border-radius: 8px;
  display: block;
  margin: 1.5rem auto;
}
/* Inline images (badges, shields) — no block treatment */
.page-content p img,
.page-content a img {
  display: inline;
  margin: 0 0.2em;
  border-radius: 3px;
  vertical-align: middle;
}

/* ===== PARTNER LOGOS ===== */
.partner-logos {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  justify-content: center;
  gap: 0.75rem 1.5rem;
  padding: 1rem 0;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.partner-logos img {
  height: 22px;
  width: auto;
  flex-shrink: 0;
  object-fit: contain;
  opacity: 0.75;
  transition: opacity var(--fast), filter var(--fast);
  border-radius: 0;
  margin: 0;
  display: inline-block;
}
.partner-logos img:hover { opacity: 1; }

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--cyan); }

/* ===== MOBILE OVERLAY ===== */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.65);
  z-index: 90;
  backdrop-filter: blur(2px);
}
.sidebar-overlay.visible { display: block; }

/* ===== WIDE CONTENT: prevent horizontal overflow on all screens ===== */
.page-content img {
  max-width: 100%;
  height: auto;
}
.page-content pre {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.page-content table {
  display: block;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  max-width: 100%;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  /* Sidebar collapses on tablets too */
  .sidebar {
    transform: translateX(calc(-1 * var(--sidebar-w)));
    box-shadow: none;
  }
  .sidebar.open {
    transform: translateX(0);
    box-shadow: 6px 0 32px rgba(0,0,0,0.5);
  }
  .main-wrap { margin-left: 0; }
  .menu-btn { display: flex; }
  .top-bar-title { display: block; }
}

@media (max-width: 600px) {
  .page-content { padding: 1.25rem 0.875rem 3rem; }

  /* Images fill the column */
  .page-content img { width: 100%; height: auto; }

  /* Partner logos: 3 per row on mobile */
  .partner-logos {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    justify-items: center;
    overflow-x: unset;
  }
  .partner-logos img { height: 20px; }

  /* Prevent any element from causing horizontal scroll */
  .main-wrap { overflow-x: hidden; }

  /* Smaller headings on phones */
  .page-content h1 { font-size: 1.4rem; }
  .page-content h2 { font-size: 1.15rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}