/* ============================================================================
   MOBILE BOTTOM NAVIGATION BAR
   Optimized for Mobile Devices
   Theme: Red, Black, White, Engineering Grid, Architectural
   Similar to Facebook's Bottom Navigation Pattern
   ============================================================================ */

:root {
    --primary-red: #CC0000;
    --dark-red: #8B0000;
    --accent-red: #FF0000;
    --bg-black: #000000;
    --bg-dark: #0A0A0A;
    --bg-nav: rgba(10, 10, 10, 0.98);
    --border-primary: rgba(204, 0, 0, 0.3);
    --border-active: rgba(204, 0, 0, 0.8);
    --text-primary: rgba(255, 255, 255, 0.95);
    --text-secondary: rgba(255, 255, 255, 0.65);
    --text-inactive: rgba(255, 255, 255, 0.45);
}

/* Mobile Bottom Navigation Container */
.mobile-bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: 65px;
    background: var(--bg-nav);
    border-top: 2px solid var(--border-primary);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 9999;
    box-shadow: 
        0 -4px 20px rgba(0, 0, 0, 0.5),
        0 -2px 8px rgba(204, 0, 0, 0.2);
}

/* Engineering Grid Pattern Overlay */
.mobile-bottom-nav::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(90deg, rgba(204, 0, 0, 0.03) 1px, transparent 1px),
        linear-gradient(0deg, rgba(204, 0, 0, 0.03) 1px, transparent 1px);
    background-size: 20px 20px;
    pointer-events: none;
    opacity: 0.5;
}

/* Navigation Inner Container */
.mobile-nav-container {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-around;
    height: 100%;
    max-width: 600px;
    margin: 0 auto;
    padding: 0 8px;
}

/* Navigation Items */
.mobile-nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 8px 4px;
    text-decoration: none;
    color: var(--text-inactive);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    min-width: 60px;
}

/* Icon Styles */
.mobile-nav-item i {
    font-size: 24px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Label Styles */
.mobile-nav-label {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    white-space: nowrap;
}

/* Hover Effect (for devices that support hover) */
@media (hover: hover) {
    .mobile-nav-item:hover {
        color: var(--text-secondary);
    }
    
    .mobile-nav-item:hover i {
        transform: translateY(-2px) scale(1.05);
    }
}

/* Active State */
.mobile-nav-item.active {
    color: var(--primary-red);
}

.mobile-nav-item.active i {
    transform: scale(1.1);
    filter: drop-shadow(0 0 8px rgba(204, 0, 0, 0.6));
}

.mobile-nav-item.active .mobile-nav-label {
    color: var(--primary-red);
    font-weight: 700;
}

/* Active Indicator */
.mobile-nav-item.active::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--primary-red), transparent);
    border-radius: 0 0 4px 4px;
    box-shadow: 0 0 10px rgba(204, 0, 0, 0.6);
    animation: activeGlow 2s ease-in-out infinite;
}

@keyframes activeGlow {
    0%, 100% {
        opacity: 1;
        box-shadow: 0 0 10px rgba(204, 0, 0, 0.6);
    }
    50% {
        opacity: 0.7;
        box-shadow: 0 0 20px rgba(204, 0, 0, 0.8);
    }
}

/* Ripple Effect on Tap */
.mobile-nav-item::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(204, 0, 0, 0.2);
    transform: translate(-50%, -50%);
    transition: width 0.4s, height 0.4s, opacity 0.4s;
    opacity: 0;
    pointer-events: none;
}

.mobile-nav-item:active::after {
    width: 100px;
    height: 100px;
    opacity: 1;
    transition: 0s;
}

/* Notification Badge (for future use) */
.mobile-nav-badge {
    position: absolute;
    top: 4px;
    right: 50%;
    transform: translateX(18px);
    min-width: 18px;
    height: 18px;
    padding: 0 4px;
    background: var(--accent-red);
    border: 2px solid var(--bg-nav);
    border-radius: 10px;
    font-size: 10px;
    font-weight: 700;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 6px rgba(255, 0, 0, 0.4);
}

/* Safe Area for Devices with Notch */
@supports (padding-bottom: env(safe-area-inset-bottom)) {
    .mobile-bottom-nav {
        padding-bottom: env(safe-area-inset-bottom);
        height: calc(65px + env(safe-area-inset-bottom));
    }
}

/* Content Padding to Account for Fixed Bottom Nav */
body {
    padding-bottom: 75px; /* 65px nav height + 10px spacing */
}

@supports (padding-bottom: env(safe-area-inset-bottom)) {
    body {
        padding-bottom: calc(75px + env(safe-area-inset-bottom));
    }
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    .mobile-bottom-nav {
        border-top-width: 3px;
    }
    
    .mobile-nav-item.active {
        color: var(--accent-red);
    }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    .mobile-nav-item,
    .mobile-nav-item i,
    .mobile-nav-label {
        transition: none;
    }
    
    .mobile-nav-item.active::before {
        animation: none;
    }
}

/* Very Small Devices (< 360px) */
@media (max-width: 359px) {
    .mobile-nav-item i {
        font-size: 22px;
    }
    
    .mobile-nav-label {
        font-size: 10px;
    }
    
    .mobile-bottom-nav {
        height: 60px;
    }
    
    body {
        padding-bottom: 70px;
    }
}

/* Landscape Mode on Small Devices */
@media (max-height: 500px) and (orientation: landscape) {
    .mobile-bottom-nav {
        height: 55px;
    }
    
    .mobile-nav-item {
        padding: 4px 4px;
    }
    
    .mobile-nav-item i {
        font-size: 20px;
    }
    
    .mobile-nav-label {
        font-size: 9px;
    }
    
    body {
        padding-bottom: 60px;
    }
}