/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --color-primary: hsl(280, 85%, 60%);
    --color-primary-light: hsl(280, 85%, 70%);
    --color-primary-dark: hsl(280, 85%, 50%);
    --color-secondary: hsl(200, 90%, 55%);
    --color-accent: hsl(340, 80%, 60%);
    
    --color-bg: hsl(240, 15%, 8%);
    --color-bg-elevated: hsl(240, 15%, 12%);
    --color-bg-card: hsl(240, 15%, 15%);
    --color-surface: hsl(240, 10%, 20%);
    
    --color-text: hsl(0, 0%, 95%);
    --color-text-secondary: hsl(0, 0%, 70%);
    --color-text-tertiary: hsl(0, 0%, 50%);
    
    --color-error: hsl(0, 80%, 60%);
    --color-success: hsl(140, 70%, 50%);
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    --gradient-glow: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(168, 85, 247, 0.4);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Animated Background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 30%, rgba(168, 85, 247, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(56, 189, 248, 0.08) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

/* Screen Management */
.screen {
    display: none;
}

.screen.active {
    display: block;
}

/* ===== LOGIN SCREEN ===== */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.login-card {
    background: var(--color-bg-card);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    width: 100%;
    max-width: 420px;
    box-shadow: var(--shadow-lg);
    animation: slideUp 0.5s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.lock-icon {
    font-size: 3rem;
    text-align: center;
    margin-bottom: var(--spacing-lg);
    animation: bounce 1s ease infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.login-card h1 {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-xs);
}

.subtitle {
    text-align: center;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
}

.input-group {
    margin-bottom: var(--spacing-lg);
}

.input-group select,
.input-group input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-surface);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--color-text);
    font-size: 1rem;
    font-family: inherit;
    transition: all var(--transition-base);
}

.input-group select:focus,
.input-group input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(168, 85, 247, 0.2);
}

.btn-primary {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--gradient-primary);
    border: none;
    border-radius: var(--radius-md);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-md);
}

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

.btn-primary:active {
    transform: translateY(0);
}

.error-message {
    color: var(--color-error);
    text-align: center;
    margin-top: var(--spacing-md);
    font-size: 0.9rem;
    min-height: 1.4em;
}

/* ===== APP HEADER ===== */
.app-header {
    background: var(--color-bg-elevated);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--spacing-md) var(--spacing-lg);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.app-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.user-badge {
    background: var(--gradient-primary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-lg);
    font-size: 0.9rem;
    font-weight: 600;
}

.btn-icon {
    background: var(--color-surface);
    border: none;
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    color: var(--color-text);
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-icon:hover {
    background: var(--color-primary);
    transform: scale(1.05);
}

/* ===== TAB NAVIGATION ===== */
.tab-nav {
    background: var(--color-bg-elevated);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-lg);
    position: sticky;
    top: 70px;
    z-index: 99;
}

.tab-btn {
    background: transparent;
    border: none;
    color: var(--color-text-secondary);
    cursor: pointer;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    transition: all var(--transition-base);
    position: relative;
}

.tab-btn:hover {
    color: var(--color-text);
    background: var(--color-surface);
}

.tab-btn.active {
    color: white;
    background: var(--gradient-primary);
}

.notification-badge {
    background: var(--color-error);
    color: white;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    font-weight: 700;
    position: absolute;
    top: 4px;
    right: 4px;
}

.notification-badge.hidden {
    display: none;
}

/* ===== TAB CONTENT ===== */
.tab-content {
    display: none;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-lg);
}

.tab-content.active {
    display: block;
}

/* ===== UPLOAD SECTION ===== */
.upload-section {
    margin-bottom: var(--spacing-xl);
    display: flex;
    justify-content: center;
}

.btn-upload {
    background: var(--gradient-glow);
    border: none;
    border-radius: var(--radius-lg);
    color: white;
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-md);
}

.btn-upload:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.upload-progress {
    margin-bottom: var(--spacing-lg);
    background: var(--color-bg-card);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
}

.upload-progress.hidden {
    display: none;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--color-surface);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin-bottom: var(--spacing-sm);
}

.progress-fill {
    height: 100%;
    background: var(--gradient-primary);
    width: 0%;
    transition: width var(--transition-base);
}

.progress-text {
    display: block;
    text-align: center;
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

/* ===== PHOTO GRID ===== */
.photo-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

@media (max-width: 768px) {
    .photo-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: var(--spacing-md);
    }
}

.photo-card {
    background: var(--color-bg-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    cursor: pointer;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.photo-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.photo-card img {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    display: block;
}

.photo-info {
    padding: var(--spacing-md);
}

.photo-user {
    font-weight: 600;
    color: var(--color-primary-light);
    font-size: 0.9rem;
}

.photo-date {
    color: var(--color-text-tertiary);
    font-size: 0.8rem;
}

.empty-state {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--color-text-secondary);
}

.empty-state.hidden {
    display: none;
}

.empty-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

/* ===== CHAT ===== */
.chat-container {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    height: calc(100vh - 180px);
}

.message-list {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.message {
    display: flex;
    flex-direction: column;
    max-width: 70%;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-10px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.message.own {
    align-self: flex-end;
}

.message.own .message-bubble {
    background: var(--gradient-primary);
}

.message-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-xs);
    padding: 0 var(--spacing-sm);
}

.message-username {
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--color-primary-light);
}

.message-time {
    font-size: 0.75rem;
    color: var(--color-text-tertiary);
}

.message-bubble {
    background: var(--color-bg-card);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    word-wrap: break-word;
}

.message.own .message-username {
    color: white;
}

.chat-input-container {
    background: var(--color-bg-elevated);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--spacing-lg);
    position: sticky;
    bottom: 0;
}

.voice-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.btn-voice {
    background: var(--color-surface);
    border: none;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    color: var(--color-text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.btn-voice:hover {
    background: var(--color-success);
    transform: scale(1.05);
}

.btn-end-call {
    background: var(--color-error);
}

.btn-end-call:hover {
    background: hsl(0, 80%, 50%);
}

.btn-voice.hidden {
    display: none;
}

.voice-status {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-success);
    font-size: 0.9rem;
    font-weight: 600;
}

.voice-status.hidden {
    display: none;
}

.pulse {
    width: 8px;
    height: 8px;
    background: var(--color-success);
    border-radius: 50%;
    animation: pulse 2s ease infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.5;
        transform: scale(1.3);
    }
}

.chat-form {
    display: flex;
    gap: var(--spacing-md);
}

.chat-form input {
    flex: 1;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--color-surface);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    color: var(--color-text);
    font-size: 1rem;
    font-family: inherit;
    transition: all var(--transition-base);
}

.chat-form input:focus {
    outline: none;
    border-color: var(--color-primary);
}

.btn-send {
    background: var(--gradient-primary);
    border: none;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.btn-send:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

/* ===== LIGHTBOX ===== */
.lightbox {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: var(--spacing-lg);
}

.lightbox.hidden {
    display: none;
}

.lightbox-close {
    position: absolute;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    background: var(--color-surface);
    border: none;
    border-radius: 50%;
    width: 48px;
    height: 48px;
    color: white;
    font-size: 2rem;
    cursor: pointer;
    transition: all var(--transition-base);
}

.lightbox-close:hover {
    background: var(--color-error);
    transform: rotate(90deg);
}

.lightbox img {
    max-width: 90%;
    max-height: 80vh;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.lightbox-info {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-bg-elevated);
    backdrop-filter: blur(20px);
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-lg);
    display: flex;
    gap: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

/* Mobile Optimizations */
@media (max-width: 768px) {
    .app-header h1 {
        font-size: 1.2rem;
    }
    
    .user-badge {
        font-size: 0.8rem;
        padding: var(--spacing-xs) var(--spacing-sm);
    }
    
    .tab-nav {
        top: 60px;
    }
    
    .tab-btn span {
        display: none;
    }
    
    .message {
        max-width: 85%;
    }
    
    .chat-container {
        height: calc(100vh - 160px);
    }
    
    .lightbox-info {
        flex-direction: column;
        gap: var(--spacing-xs);
        text-align: center;
    }
}