/* ==========================================================================
   Responsive Layout (Desktop Sidebar / Mobile Floating Navigation)
   ========================================================================== */

.app-container {
    display: flex;
    min-height: 100vh;
    background-color: var(--bg-main);
}

/* Sidebar Desktop */
.app-sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-surface);
    border-right: 1px solid var(--border-color);
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    display: flex;
    flex-direction: column;
    padding: 24px 16px 16px 16px;
    z-index: 100;
    transition: width var(--transition-normal), background-color var(--transition-normal);
    backdrop-filter: blur(16px);
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 4px 14px 28px 14px;
    font-family: var(--font-display);
    font-size: 26px;
    font-weight: 800;
    letter-spacing: -0.5px;
    color: var(--text-main);
}

.brand-logo i {
    font-size: 30px;
    color: var(--primary);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: heartBeat 2.5s ease-in-out infinite;
    display: inline-block;
}

.brand-logo span {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 900;
}

.nav-menu {
    display: flex;
    flex-direction: column;
    gap: 6px;
    flex: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    font-size: 15px;
    font-weight: 600;
    color: var(--text-muted);
    position: relative;
    transition: all var(--transition-fast);
}

.nav-item:hover {
    background-color: var(--bg-surface-hover);
    color: var(--text-main);
    transform: translateX(4px);
}

.nav-item.active {
    font-weight: 700;
    color: var(--primary);
    background: var(--primary-light);
}

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

.nav-item i {
    font-size: 22px;
    width: 28px;
    text-align: center;
    transition: transform var(--transition-fast), color var(--transition-fast);
}

.nav-item .badge-dot {
    width: 8px;
    height: 8px;
    background-color: var(--primary);
    border-radius: 50%;
    position: absolute;
    right: 16px;
    box-shadow: 0 0 8px var(--primary);
    animation: pulseGlow 2s infinite;
}

/* Sidebar Footer */
.sidebar-footer {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding-top: 14px;
    border-top: 1px solid var(--border-color);
}

.sidebar-user-card {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 12px;
    border-radius: var(--radius-md);
    background: var(--bg-surface-hover);
    margin-top: 4px;
    transition: background var(--transition-fast);
}

.sidebar-user-card:hover {
    background: var(--bg-surface-active);
}

/* Main Content Area */
.app-main {
    flex: 1;
    margin-left: var(--sidebar-width);
    min-height: 100vh;
    padding: 28px 24px 80px 24px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    transition: margin-left var(--transition-normal);
}

.app-workspace-content {
    flex: 1;
    width: 100%;
    display: flex;
    justify-content: center;
}

.feed-container {
    width: 100%;
    max-width: 630px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* Right Panel for Suggestions & Trends */
.app-right-panel {
    width: var(--right-panel-width);
    margin-left: 32px;
    display: none;
    flex-shrink: 0;
}

.right-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    margin-bottom: 20px;
    transition: box-shadow var(--transition-normal), transform var(--transition-normal);
}

.right-card:hover {
    box-shadow: var(--shadow-md);
}

.right-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.right-card-title {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-main);
}

.trend-tag-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    border-radius: var(--radius-full);
    background: var(--bg-surface-hover);
    color: var(--text-main);
    font-size: 13px;
    font-weight: 600;
    margin: 4px 4px 4px 0;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
}

.trend-tag-chip:hover {
    background: var(--primary-light);
    color: var(--primary);
    border-color: rgba(255, 45, 85, 0.2);
    transform: translateY(-2px);
}

@media (min-width: 1180px) {
    .app-right-panel {
        display: block;
    }
}

/* Mobile Header (Frosted Glass) */
.mobile-header {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background-color: var(--bg-glass);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--border-color);
    padding: 0 18px;
    align-items: center;
    justify-content: space-between;
    z-index: 150;
    box-shadow: var(--shadow-xs);
}

/* Mobile Bottom Navigation (Floating Glass Bar) */
.mobile-bottom-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--bottom-nav-height);
    background-color: var(--bg-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid var(--border-color);
    align-items: center;
    justify-content: space-around;
    z-index: 150;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.05);
}

.bottom-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 22px;
    flex: 1;
    height: 100%;
    position: relative;
    transition: color var(--transition-fast), transform var(--transition-fast);
}

.bottom-nav-item.active {
    color: var(--primary);
}

.bottom-nav-item.active::after {
    content: '';
    position: absolute;
    bottom: 6px;
    width: 4px;
    height: 4px;
    background-color: var(--primary);
    border-radius: 50%;
    box-shadow: 0 0 6px var(--primary);
}

.bottom-nav-item:active {
    transform: scale(0.9);
}

/* Floating Action Button for Create Post on Mobile */
.bottom-nav-fab {
    width: 46px;
    height: 46px;
    border-radius: 50%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #FFF !important;
    font-size: 22px;
    box-shadow: 0 4px 16px rgba(255, 45, 85, 0.45);
    margin-top: -12px;
    transition: transform var(--transition-spring), box-shadow var(--transition-fast);
}

.bottom-nav-fab:hover, .bottom-nav-fab:active {
    transform: scale(1.1) rotate(90deg);
    box-shadow: 0 6px 20px rgba(255, 45, 85, 0.6);
}

/* Tablet Responsive (768px - 1023px) */
@media (max-width: 1023px) {
    .app-sidebar {
        width: var(--sidebar-collapsed-width);
        padding: 20px 8px;
        align-items: center;
    }
    .brand-logo span, .nav-item span, .sidebar-footer span, .sidebar-user-card span {
        display: none;
    }
    .brand-logo {
        padding: 0 0 20px 0;
        justify-content: center;
    }
    .nav-item {
        justify-content: center;
        padding: 12px;
    }
    .nav-item:hover {
        transform: scale(1.08);
    }
    .app-main {
        margin-left: var(--sidebar-collapsed-width);
    }
}

/* Mobile Responsive (< 768px) */
@media (max-width: 767px) {
    .app-sidebar {
        display: none;
    }
    .app-top-header {
        display: none;
    }
    .mobile-header, .mobile-bottom-nav {
        display: flex;
    }
    .app-main {
        margin-left: 0;
        padding-top: calc(var(--header-height) + 12px);
        padding-bottom: calc(var(--bottom-nav-height) + 24px);
        padding-left: 12px;
        padding-right: 12px;
    }
}