:root {
  --bg-color: #0d1117;
  --surface-color: #161b22;
  --surface-border: #30363d;
  --text-primary: #e6edf3;
  --text-secondary: #8b949e;
  --accent-color: #58a6ff;
  --accent-hover: #1f6feb;
  --danger-color: #f85149;
  --success-color: #3fb950;
  --glass-bg: rgba(22, 27, 34, 0.7);
  --glass-border: rgba(48, 54, 61, 0.5);
  --font-main: 'Rubik', 'Inter', system-ui, -apple-system, sans-serif;
  --font-accent: 'Heebo', sans-serif;
}

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

body {
  background-color: var(--bg-color);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.5;
  overflow-x: hidden;
}

/* Glassmorphism Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 64px;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  padding: 0 2rem;
  z-index: 1000;
  justify-content: space-between;
}

.nav-brand {
  font-family: var(--font-accent);
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--accent-color);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-search {
  flex: 1;
  max-width: 400px;
  position: relative;
  margin: 0 2rem;
}

.nav-search i {
  position: absolute;
  right: 0.8rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  width: 18px;
}

.nav-search input {
  width: 100%;
  background: var(--surface-color);
  border: 1px solid var(--surface-border);
  padding: 0.5rem 2.5rem 0.5rem 1rem;
  border-radius: 20px;
  color: var(--text-primary);
  outline: none;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.nav-search input:focus {
  border-color: var(--accent-color);
  box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.2);
}

.nav-actions {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

.nav-item {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.3s;
  cursor: pointer;
}

.nav-item:hover {
  color: var(--accent-color);
}

/* Main Layout */
.container {
  max-width: 1200px;
  margin: 80px auto 2rem;
  padding: 0 1rem;
  display: grid;
  grid-template-columns: 240px 1fr 300px;
  gap: 2rem;
}

@media (max-width: 1024px) {
  .container {
    grid-template-columns: 1fr;
  }
  .sidebar-left, .sidebar-right {
    display: none;
  }
}

/* Category & Title Section */
.hero {
  grid-column: 1 / -1;
  padding: 2rem 0;
}

.hero h1 {
  font-size: 2.5rem;
  font-family: var(--font-accent);
  background: linear-gradient(90deg, #fff, #58a6ff);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Topic Card */
.topic-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.topic-card {
  background: var(--surface-color);
  border: 1px solid var(--surface-border);
  border-radius: 12px;
  padding: 1.25rem;
  display: flex;
  gap: 1rem;
  transition: transform 0.2s, box-shadow 0.2s;
  cursor: pointer;
}

.topic-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
  border-color: var(--accent-color);
}

.user-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, #1f6feb, #58a6ff);
  flex-shrink: 0;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-family: var(--font-accent);
  color: white;
  font-size: 1.2rem;
}

.user-avatar::after {
  content: '';
  position: absolute;
  bottom: 2px;
  right: 2px;
  width: 10px;
  height: 10px;
  background: var(--success-color);
  border: 2px solid var(--surface-color);
  border-radius: 50%;
}

/* Permission Modal */
#permission-modal {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.9);
    background: var(--surface-color);
    border: 1px solid var(--danger-color);
    padding: 2rem;
    border-radius: 12px;
    z-index: 2000;
    box-shadow: 0 10px 40px rgba(0,0,0,0.8);
    display: none;
    text-align: center;
    opacity: 0;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

#permission-modal.active {
    display: block;
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
}

#overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.8);
    backdrop-filter: blur(4px);
    z-index: 1999;
    display: none;
}

.topic-info h3 {
  font-size: 1.1rem;
  margin-bottom: 0.25rem;
}

.topic-meta {
  font-size: 0.85rem;
  color: var(--text-secondary);
  display: flex;
  gap: 1rem;
}

.topic-meta span {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

/* Sidebar Sections */
.sidebar-box {
  background: var(--surface-color);
  border: 1px solid var(--surface-border);
  border-radius: 12px;
  padding: 1rem;
  margin-bottom: 1.5rem;
}

.sidebar-box h4 {
  margin-bottom: 1rem;
  font-family: var(--font-accent);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-color);
}

.tag {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    background: var(--bg-color);
    border: 1px solid var(--surface-border);
    border-radius: 12px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin: 0.2rem;
    transition: all 0.2s;
}

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

/* Float Button */
.fab {
    position: fixed;
    bottom: 2rem;
    left: 2rem;
    background: var(--accent-color);
    color: white;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    cursor: pointer;
    transition: all 0.2s;
    z-index: 1000;
}

.fab:hover {
    background: var(--accent-hover);
    transform: scale(1.1);
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-in {
  animation: fadeIn 0.5s ease forwards;
}