/* CSS Variables & Theme (Dark Mode Base) */
:root {
    /* Color Palette */
    --bg-base: #0f172a;
    --bg-surface: rgba(30, 41, 59, 0.7);
    --bg-surface-hover: rgba(51, 65, 85, 0.8);
    
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-glow: rgba(99, 102, 241, 0.5);
    
    --accent: #ec4899;
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    --border-light: rgba(255, 255, 255, 0.08);
    --border-focus: rgba(99, 102, 241, 0.4);

    /* Glassmorphism */
    --glass-blur: blur(16px);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    
    /* Layout */
    --sidebar-width: 260px;
    --right-sidebar-width: 320px;
    --header-height: 80px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--bg-base);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    /* Subtly animated background gradient */
    background: radial-gradient(circle at top left, #1e1b4b, #0f172a 40%),
                radial-gradient(circle at bottom right, #311138, #0f172a 40%);
    background-attachment: fixed;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

button {
    background: none;
    border: none;
    cursor: pointer;
    font-family: inherit;
    color: inherit;
}

input {
    font-family: inherit;
}

/* Utilities */
.glass-panel {
    background: var(--bg-surface);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    box-shadow: var(--glass-shadow);
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid transparent;
    transition: var(--transition-fast);
}

.avatar:hover {
    border-color: var(--primary);
}

/* App Container */
.app-container {
    display: flex;
    max-width: 1600px;
    margin: 0 auto;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    height: 100vh;
    position: sticky;
    top: 0;
    padding: 24px;
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border-light);
    background: linear-gradient(180deg, rgba(15,23,42,0.8) 0%, rgba(15,23,42,0) 100%);
    backdrop-filter: blur(10px);
    z-index: 10;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 24px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 48px;
    text-shadow: 0 0 20px var(--primary-glow);
}

.logo i {
    font-size: 32px;
}

.nav-menu {
    display: flex;
    flex-direction: column;
    gap: 8px;
    flex: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 12px 16px;
    border-radius: 12px;
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition-fast);
}

.nav-item i {
    font-size: 24px;
    transition: var(--transition-fast);
}

.nav-item:hover {
    background: var(--bg-surface-hover);
    color: var(--text-primary);
}

.nav-item:hover i {
    transform: scale(1.1);
    color: var(--primary);
}

.nav-item.active {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2), rgba(99, 102, 241, 0.05));
    color: var(--primary);
    border-left: 3px solid var(--primary);
}

.user-profile-menu {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px;
    border-radius: 16px;
    background: var(--bg-surface);
    border: 1px solid var(--border-light);
    margin-top: auto;
    cursor: pointer;
    transition: var(--transition-fast);
}

.user-profile-menu:hover {
    background: var(--bg-surface-hover);
}

.user-profile-menu .user-info {
    display: flex;
    flex-direction: column;
    flex: 1;
}

.user-profile-menu .name {
    font-size: 14px;
    font-weight: 600;
}

.user-profile-menu .role {
    font-size: 12px;
    color: var(--text-secondary);
}

.user-profile-menu .options {
    color: var(--text-muted);
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 0 32px;
}

/* Header */
.top-header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(12px);
    z-index: 5;
    padding: 16px 0;
    margin-bottom: 24px;
}

.search-bar {
    display: flex;
    align-items: center;
    background: var(--bg-surface);
    border: 1px solid var(--border-light);
    border-radius: 24px;
    padding: 12px 24px;
    width: 400px;
    transition: var(--transition-fast);
}

.search-bar:focus-within {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
}

.search-bar i {
    color: var(--text-muted);
    font-size: 20px;
    margin-right: 12px;
}

.search-bar input {
    background: none;
    border: none;
    color: var(--text-primary);
    outline: none;
    width: 100%;
    font-size: 15px;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.icon-btn {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--bg-surface);
    border: 1px solid var(--border-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    color: var(--text-secondary);
    transition: var(--transition-fast);
    position: relative;
}

.icon-btn:hover {
    background: var(--bg-surface-hover);
    color: var(--text-primary);
}

.icon-btn::after {
    content: '';
    position: absolute;
    top: 10px;
    right: 12px;
    width: 8px;
    height: 8px;
    background: var(--accent);
    border-radius: 50%;
    border: 2px solid var(--bg-surface);
}

.primary-btn {
    background: var(--primary);
    color: white;
    padding: 12px 24px;
    border-radius: 24px;
    font-weight: 600;
    font-size: 15px;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition-fast);
    box-shadow: 0 4px 14px var(--primary-glow);
}

.primary-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--primary-glow);
}

/* =========================================
   Classic Board View Styles (게시글 상세)
   ========================================= */

.board-view-container {
    background: var(--bg-surface);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 32px;
    margin-bottom: 24px;
}

.board-view-header {
    border-bottom: 2px solid var(--border-light);
    padding-bottom: 20px;
    margin-bottom: 24px;
}

.board-view-title {
    font-size: 24px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.board-view-info {
    display: flex;
    justify-content: space-between;
    font-size: 14px;
    color: var(--text-muted);
}

.board-view-info .left span {
    margin-right: 16px;
}

.board-view-content {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-secondary);
    padding: 20px 0;
    border-bottom: 1px solid var(--border-light);
    margin-bottom: 24px;
}

/* =========================================
   Content Wrapper (Feed + Right Sidebar)
   ========================================= */
.content-wrapper {
    display: flex;
    gap: 32px;
    align-items: flex-start;
}

/* Right Sidebar (기존 유지) */
.right-sidebar {
    width: var(--right-sidebar-width);
    display: flex;
    flex-direction: column;
    gap: 24px;
    position: sticky;
    top: calc(var(--header-height) + 24px);
}

.widget-title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-light);
}

.trending-widget {
    padding: 20px;
}

.trend-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.trend-list li {
    display: flex;
    align-items: center;
    gap: 16px;
    cursor: pointer;
    transition: var(--transition-fast);
}

.trend-list li:hover {
    transform: translateX(4px);
}

.trend-list .rank {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-muted);
    width: 20px;
    text-align: center;
}

.trend-info {
    display: flex;
    flex-direction: column;
}

.trend-info .topic-name {
    font-size: 15px;
    font-weight: 500;
    margin-bottom: 4px;
}

.trend-info .posts-count {
    font-size: 12px;
    color: var(--text-muted);
}

/* Responsive Design */
@media (max-width: 1200px) {
    .right-sidebar {
        display: none;
    }
}

@media (max-width: 900px) {
    .sidebar {
        width: 80px;
        padding: 24px 16px;
    }
    
    .sidebar .logo span,
    .sidebar .nav-item span,
    .sidebar .user-profile-menu .user-info,
    .sidebar .user-profile-menu .options {
        display: none;
    }
    
    .sidebar .logo i {
        margin: 0 auto;
    }
    
    .sidebar .nav-item {
        justify-content: center;
        padding: 12px;
    }
    
    .sidebar .nav-item i {
        margin: 0;
    }
    
    .user-profile-menu {
        padding: 8px;
        justify-content: center;
    }
}

@media (max-width: 600px) {
    .main-content {
        padding: 0 16px;
    }
    
    .search-bar {
        display: none;
    }
    
    .primary-btn span {
        display: none;
    }
}