:root {
  --bg:       #080c12;
  --surface:  #0e1420;
  --glass:    rgba(255,255,255,0.04);
  --border:   rgba(255,255,255,0.08);
  --accent:   #00e5c3;
  --accent2:  #6c63ff;
  --txt:      #e2e8f0;
  --txt-muted:#6b7ea0;
  --card-glow:rgba(0,229,195,0.06);
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--txt);
  font-family: 'Figtree', sans-serif;
  min-height: 100vh;
  overflow-x: hidden;
}
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0,229,195,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,229,195,0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  z-index: 0;
}
body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 0;
  opacity: 0.4;
}
#app { position: relative; z-index: 1; }
.font-display { font-family: 'Syne', sans-serif; }
.font-mono    { font-family: 'DM Mono', monospace; }
.glass {
  background: var(--glass);
  border: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.algo-card {
  background: var(--glass);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem;
  cursor: pointer;
  transition: transform 0.22s cubic-bezier(.4,0,.2,1), border-color 0.22s ease, box-shadow 0.22s ease;
  position: relative;
  overflow: hidden;
}
.algo-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 20%, rgba(0,229,195,0.07) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.3s ease;
}
.algo-card:hover { transform: translateY(-4px); border-color: rgba(0,229,195,0.3); box-shadow: 0 8px 32px var(--card-glow); }
.algo-card:hover::before { opacity: 1; }
.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 0.7rem;
  font-family: 'DM Mono', monospace;
  letter-spacing: 0.05em;
  background: rgba(0,229,195,0.1);
  border: 1px solid rgba(0,229,195,0.25);
  color: var(--accent);
}
nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(8,12,18,0.82);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}
.orb { position: absolute; border-radius: 50%; filter: blur(80px); pointer-events: none; }
.orb-1 { width: 420px; height: 420px; background: rgba(0,229,195,0.12); top: -100px; left: -80px; }
.orb-2 { width: 360px; height: 360px; background: rgba(108,99,255,0.10); top: 40px; right: -60px; }
#search-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.72);
  backdrop-filter: blur(8px);
  z-index: 100;
  display: flex; align-items: flex-start; justify-content: center;
  padding-top: 10vh;
  opacity: 0; pointer-events: none;
  transition: opacity 0.2s ease;
}
#search-overlay.open { opacity: 1; pointer-events: all; }
#search-modal {
  width: min(600px, 92vw);
  background: #0e1420;
  border: 1px solid var(--border);
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 24px 80px rgba(0,0,0,0.6), 0 0 0 1px rgba(0,229,195,0.08);
  transform: translateY(-12px) scale(0.97);
  transition: transform 0.22s cubic-bezier(.4,0,.2,1);
}
#search-overlay.open #search-modal { transform: translateY(0) scale(1); }
#search-input {
  width: 100%;
  background: transparent;
  border: none;
  outline: none;
  color: var(--txt);
  font-size: 1.1rem;
  font-family: 'Figtree', sans-serif;
  padding: 1.2rem 1.5rem;
}
#search-input::placeholder { color: var(--txt-muted); }
.search-result-item {
  padding: 0.85rem 1.5rem;
  cursor: pointer;
  transition: background 0.15s ease;
  display: flex; align-items: center; gap: 12px;
  border-top: 1px solid var(--border);
}
.search-result-item:hover { background: rgba(0,229,195,0.06); }
.lang-tab {
  padding: 6px 14px;
  border-radius: 8px;
  font-size: 0.78rem;
  font-family: 'DM Mono', monospace;
  cursor: pointer;
  color: var(--txt-muted);
  border: 1px solid transparent;
  transition: all 0.15s ease;
}
.lang-tab.active, .lang-tab:hover {
  color: var(--accent);
  background: rgba(0,229,195,0.08);
  border-color: rgba(0,229,195,0.2);
}
pre[class*="language-"] {
  background: #060a0f !important;
  border: 1px solid var(--border);
  border-radius: 12px;
  margin: 0;
  padding: 1.5rem;
  overflow-x: auto;
  font-family: 'DM Mono', monospace;
  font-size: 0.85rem;
  line-height: 1.7;
}
.md-content h1, .md-content h2, .md-content h3 { font-family: 'Syne', sans-serif; color: var(--txt); margin: 1.4em 0 0.6em; }
.md-content h1 { font-size: 1.5rem; }
.md-content h2 { font-size: 1.2rem; }
.md-content h3 { font-size: 1rem; }
.md-content p  { color: #94a3b8; line-height: 1.75; margin: 0.75em 0; }
.md-content code { font-family: 'DM Mono', monospace; background: rgba(0,229,195,0.08); color: var(--accent); padding: 2px 6px; border-radius: 5px; font-size: 0.85em; }
.md-content pre  { background: #060a0f; border: 1px solid var(--border); border-radius: 10px; padding: 1rem; overflow-x: auto; margin: 1em 0; }
.md-content pre code { background: none; color: #94a3b8; }
.md-content ul, .md-content ol { padding-left: 1.5rem; color: #94a3b8; line-height: 1.75; }
.md-content li { margin: 0.3em 0; }
.md-content strong { color: var(--txt); font-weight: 600; }
.md-content a { color: var(--accent); text-decoration: underline; }
.md-content blockquote { border-left: 3px solid var(--accent); padding: 0.5rem 1rem; background: rgba(0,229,195,0.04); border-radius: 0 8px 8px 0; margin: 1em 0; }
.md-content hr { border: none; border-top: 1px solid var(--border); margin: 1.5em 0; }
.page { animation: fadeIn 0.3s ease both; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
.algo-card { animation: cardIn 0.4s ease both; }
@keyframes cardIn { from { opacity: 0; transform: translateY(18px); } to { opacity: 1; transform: translateY(0); } }
.complexity-box {
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem 1.4rem;
}
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 3px; }
.btn-primary {
  background: var(--accent);
  color: #080c12;
  font-weight: 600;
  font-family: 'Figtree', sans-serif;
  border: none;
  border-radius: 10px;
  padding: 10px 22px;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.15s;
  font-size: 0.9rem;
}
.btn-primary:hover { opacity: 0.88; transform: translateY(-1px); }
.btn-ghost {
  background: transparent;
  color: var(--txt-muted);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 9px 20px;
  cursor: pointer;
  transition: all 0.2s;
  font-family: 'Figtree', sans-serif;
  font-size: 0.9rem;
}
.btn-ghost:hover { color: var(--txt); border-color: rgba(255,255,255,0.2); }
kbd {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 2px 7px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 5px;
  font-family: 'DM Mono', monospace;
  font-size: 0.72rem;
  color: var(--txt-muted);
}
.section-label {
  font-family: 'DM Mono', monospace;
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}
@media (max-width: 640px) {
  .orb-1, .orb-2 { width: 220px; height: 220px; }
}
select {
  background: rgba(255,255,255,0.04);
  color: var(--txt);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 10px;
  font-family: 'DM Mono', monospace;
  font-size: 0.75rem;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' stroke='%23a5b4fc' stroke-width='2' viewBox='0 0 24 24'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  background-size: 12px;
  padding-right: 28px;
}
select option { background: #0e1420; color: var(--txt); }

/* Auth styles */
@keyframes authSlideIn {
  from { opacity:0; transform:translateY(16px) scale(0.97); }
  to   { opacity:1; transform:translateY(0) scale(1); }
}
@keyframes spin { to { transform:rotate(360deg); } }
.auth-provider-btn:hover { background:rgba(255,255,255,0.08) !important; border-color:rgba(255,255,255,0.18) !important; transform:translateY(-1px); }
#auth-overlay.open { display:flex !important; }
#user-nav-btn {
  display:flex;align-items:center;gap:8px;
  padding:6px 12px;border-radius:10px;
  background:rgba(255,255,255,0.04);border:1px solid rgba(255,255,255,0.09);
  color:#e2e8f0;cursor:pointer;font-family:'Figtree',sans-serif;font-size:0.82rem;
  transition:all 0.18s ease;
}
#user-nav-btn:hover { background:rgba(0,229,195,0.08); border-color:rgba(0,229,195,0.25); }
.bm-btn {
  background:transparent;border:1px solid rgba(255,255,255,0.1);border-radius:10px;
  padding:8px 14px;color:#6b7ea0;cursor:pointer;
  font-family:'Figtree',sans-serif;font-size:0.82rem;
  display:flex;align-items:center;gap:6px;transition:all 0.18s ease;
}
.bm-btn:hover  { border-color:rgba(255,255,255,0.2);color:#e2e8f0; }
.bm-btn.active { background:rgba(0,229,195,0.1);border-color:rgba(0,229,195,0.3);color:#00e5c3; }