:root {
  --bg: #0a0a0f;
  --surface: #111118;
  --surface2: #1a1a26;
  --border: #2a2a40;
  --accent: #00d4ff;
  --accent2: #ff007a;
  --accent3: #00ffa3;
  --text: #e8e8f0;
  --muted: #888899;
  --py: #3d7aed;
  --js: #f0c040;
  --java: #e05a2b;
  --php: #8892bf;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(
      ellipse 60% 40% at 20% 10%,
      rgba(124, 106, 255, 0.08) 0%,
      transparent 60%
    ),
    radial-gradient(
      ellipse 50% 40% at 80% 90%,
      rgba(106, 255, 212, 0.06) 0%,
      transparent 60%
    ),
    radial-gradient(
      ellipse 40% 30% at 70% 20%,
      rgba(255, 106, 155, 0.05) 0%,
      transparent 50%
    );
  pointer-events: none;
  z-index: 0;
}

header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.logo {
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--accent);
  white-space: nowrap;
}

.logo span {
  color: var(--text);
}

.search-wrap {
  flex: 1;
  min-width: 180px;
  max-width: 320px;
  position: relative;
}

.search-wrap input {
  width: 100%;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 7px 12px;
  outline: none;
  transition: border-color 0.2s;
}

.search-wrap input:focus {
  border-color: var(--accent);
}

.lang-tabs {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.lang-tab {
  padding: 5px 14px;
  border-radius: 6px;
  border: 1.5px solid var(--border);
  background: transparent;
  color: var(--muted);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.18s;
  letter-spacing: 0.01em;
}

.lang-tab:hover {
  color: var(--text);
  border-color: #555;
}

.lang-tab.active[data-lang='python'] {
  background: rgba(61, 122, 237, 0.18);
  border-color: var(--py);
  color: var(--py);
}

.lang-tab.active[data-lang='javascript'] {
  background: rgba(240, 192, 64, 0.15);
  border-color: var(--js);
  color: var(--js);
}

.lang-tab.active[data-lang='java'] {
  background: rgba(224, 90, 43, 0.15);
  border-color: var(--java);
  color: var(--java);
}

.lang-tab.active[data-lang='php'] {
  background: rgba(136, 146, 191, 0.15);
  border-color: var(--php);
  color: var(--php);
}

.main {
  position: relative;
  z-index: 1;
  display: flex;
  /* Calculate height based on header/footer spacing if possible, keeping original for safety */
  height: calc(100vh - 57px);
  overflow: hidden;
}

.sidebar {
  width: 230px;
  flex-shrink: 0;
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 12px 8px;
  background: rgba(17, 17, 24, 0.7);
}

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

.sidebar::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

.topic-btn {
  display: block;
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  border-radius: 6px;
  padding: 8px 10px;
  color: var(--muted);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
  margin-bottom: 2px;
}

.topic-btn:hover {
  color: var(--text);
  background: var(--surface2);
}

.topic-btn.active {
  color: var(--accent);
  background: rgba(0, 212, 255, 0.1);
  font-weight: 600;
}

.content {
  flex: 1;
  overflow-y: auto;
  padding: 32px;
}

.content::-webkit-scrollbar {
  width: 5px;
}

.content::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

.topic-header {
  margin-bottom: 20px;
}

.topic-title {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

.topic-title span {
  color: var(--accent);
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(500px, 1fr));
  gap: 20px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  transition: border-color 0.2s, transform 0.15s;
  animation: fadeIn 0.25s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.card:hover {
  border-color: #3a3a55;
  transform: translateY(-2px);
}

.card-head {
  padding: 14px 20px 10px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--border);
}

.card-title {
  flex: 1;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
}

.badge {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 4px;
  background: rgba(0, 212, 255, 0.1);
  color: var(--accent);
  border: 1px solid rgba(0, 212, 255, 0.2);
  white-space: nowrap;
}

.card-note {
  padding: 10px 20px 6px;
  font-size: 0.78rem;
  color: var(--muted);
  font-weight: 400;
  line-height: 1.5;
}

.card-code {
  padding: 16px 20px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.6;
  color: #c8d0f0;
  background: rgba(0, 0, 0, 0.35);
  border-top: 1px solid rgba(255, 255, 255, 0.04);
  white-space: pre;
  tab-size: 4;
  -moz-tab-size: 4;
  font-variant-ligatures: none;
  text-rendering: optimizeLegibility;
  overflow-x: auto;
  position: relative;
  border-radius: 0 0 12px 12px;
}

.card-code::-webkit-scrollbar {
  height: 3px;
}

.card-code::-webkit-scrollbar-thumb {
  background: var(--border);
}

.copy-btn {
  position: absolute;
  top: 6px;
  right: 8px;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--muted);
  font-size: 0.65rem;
  font-family: var(--font-sans);
  font-weight: 600;
  padding: 2px 7px;
  cursor: pointer;
  transition: all 0.15s;
  opacity: 0;
}

.card-code:hover .copy-btn {
  opacity: 1;
}

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

.no-results {
  text-align: center;
  color: var(--muted);
  padding: 60px 20px;
  font-size: 0.95rem;
}

footer {
  text-align: center;
}

small {
    font-size: small;
}

.link {
    color: var(--accent);
    cursor: pointer;
    font-weight: bold;
    text-decoration: none;
}

/* Keyword/Token Styling */
.kw {
  color: #c792ea;
  font-weight: 600;
}

.fn {
  color: #82aaff;
}

.st {
  color: #c3e88d;
}

.cm {
  color: #546e7a;
  font-style: italic;
}

.nm {
  color: #f78c6c;
}

.op {
  color: #89ddff;
}

/* Utility */
.active {
  display: block !important;
}

/* Menu Toggle (Hamburger) */
.menu-toggle {
  display: none; /* Hidden on desktop */
  background: transparent;
  border: 1px solid var(--accent);
  padding: 8px;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.menu-toggle:hover {
  box-shadow: 0 0 10px var(--accent);
  border-color: var(--accent);
}

.hamburger {
  width: 24px;
  height: 18px;
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.hamburger span {
  display: block;
  height: 2px;
  width: 100%;
  background-color: var(--accent);
  border-radius: 2px;
  transition: all 0.4s cubic-bezier(0.68, -0.6, 0.32, 1.6);
  transform-origin: center;
}

/* Animated States */
.menu-toggle.is-active .hamburger span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.menu-toggle.is-active .hamburger span:nth-child(2) {
  opacity: 0;
  transform: translateX(-10px);
}

.menu-toggle.is-active .hamburger span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* Media Queries */
@media (max-width: 1100px) {
  .cards-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  /* Mobile Sidebar Styles */
  .sidebar {
    position: fixed;
    left: -280px;
    top: 110px;
    bottom: 0;
    width: 250px;
    z-index: 1000;
    transition: left 0.3s ease;
    background: var(--bg);
    color: var(--muted);
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.1);
  }

  .sidebar.active {
    left: 0;
  }

  .menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
  }
}