/* ============================================
   RESPONSIVE & MOBILE STYLES
   ============================================ */

/* Tablets (768px and below) */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.2rem; }

    .chat-sidebar {
        width: 100%;
        height: 50%;
        border-right: none;
        border-bottom: 2px solid var(--border-color);
        flex-direction: row;
    }

    .sidebar-header {
        flex: 0 0 auto;
        padding: var(--spacing-md);
        border-right: 2px solid var(--border-color);
        border-bottom: none;
    }

    .users-list-container {
        flex: 1;
        overflow-x: auto;
        overflow-y: hidden;
        padding: var(--spacing-md) 0;
    }

    .users-list {
        flex-direction: row;
        flex-wrap: nowrap;
        padding: 0 var(--spacing-md);
        min-width: min-content;
    }

    .user-item {
        flex-direction: column;
        align-items: center;
        min-width: 80px;
        text-align: center;
        gap: var(--spacing-sm);
    }

    .user-item-avatar {
        width: 50px;
        height: 50px;
    }

    .user-item-name,
    .user-item-status {
        font-size: 0.75rem;
    }

    .sidebar-footer {
        display: none;
    }

    .chat-wrapper {
        flex-direction: column;
    }

    .chat-main {
        flex: 1;
        width: 100%;
    }
}

/* Mobile (480px and below) */
@media (max-width: 480px) {
    :root {
        --spacing-lg: 16px;
        --spacing-xl: 20px;
    }

    body {
        font-size: 14px;
    }

    h1 { font-size: 1.5rem; }
    h2 { font-size: 1.2rem; }
    h3 { font-size: 1rem; }
    h4 { font-size: 0.95rem; }

    .app-container {
        height: 100vh;
        flex-direction: column;
    }

    /* Auth Section Mobile */
    .auth-container {
        max-width: 100%;
        width: 95%;
        padding: var(--spacing-lg);
    }

    .app-title {
        font-size: 1.8rem;
    }

    .title-icon {
        font-size: 2rem;
    }

    .form-group {
        margin-bottom: var(--spacing-md);
    }

    /* Chat Section Mobile */
    .chat-section {
        display: flex;
        flex-direction: column;
    }

    .chat-wrapper {
        width: 100%;
        height: 100%;
    }

    .chat-sidebar {
        position: absolute;
        width: 250px;
        height: 100%;
        left: -250px;
        top: 0;
        z-index: 100;
        border-right: 2px solid var(--border-color);
        border-bottom: none;
        flex-direction: column;
        transition: left 0.3s ease;
        box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
    }

    .chat-sidebar.active {
        left: 0;
    }

    .sidebar-header {
        border-right: none;
        border-bottom: 2px solid var(--border-color);
    }

    .users-list-container {
        flex: 1;
        overflow-x: hidden;
        overflow-y: auto;
        padding: var(--spacing-md);
    }

    .users-list {
        flex-direction: column;
        flex-wrap: wrap;
        padding: 0;
    }

    .user-item {
        flex-direction: row;
        align-items: center;
        min-width: auto;
        text-align: left;
        width: 100%;
    }

    .sidebar-footer {
        display: block;
        padding: var(--spacing-md);
        border-top: 2px solid var(--border-color);
    }

    .mobile-toggle {
        display: flex;
    }

    .chat-header {
        padding: var(--spacing-md);
    }

    .chat-header-left h2 {
        font-size: 1.1rem;
    }

    .messages-container {
        padding: var(--spacing-md);
    }

    .message-content {
        max-width: 85%;
    }

    /* Message Input Mobile */
    .message-input-area {
        padding: var(--spacing-md);
    }

    .input-toolbar {
        gap: var(--spacing-sm);
        margin-bottom: var(--spacing-sm);
    }

    .input-wrapper {
        gap: var(--spacing-sm);
    }

    .message-input {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 14px;
    }

    .btn-send {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 1rem;
    }

    /* Modal Mobile */
    .modal-content {
        width: 95%;
        max-height: 90vh;
    }

    .emoji-grid {
        grid-template-columns: repeat(auto-fill, minmax(35px, 1fr));
    }

    .emoji-item {
        width: 35px;
        height: 35px;
        font-size: 1.2rem;
    }

    /* Notification Toast Mobile */
    .notification-toast {
        bottom: var(--spacing-md);
        right: var(--spacing-md);
        left: var(--spacing-md);
        max-width: none;
    }

    /* Welcome Message Mobile */
    .welcome-icon {
        font-size: 3rem;
    }

    .welcome-message h2 {
        font-size: 1.3rem;
    }

    .welcome-message p {
        font-size: 0.9rem;
    }
}

/* Extra Small Devices (320px and below) */
@media (max-width: 320px) {
    :root {
        --spacing-md: 12px;
        --spacing-lg: 14px;
        --spacing-xl: 16px;
    }

    h1 { font-size: 1.3rem; }
    h2 { font-size: 1.1rem; }
    h3 { font-size: 0.95rem; }

    .auth-container {
        padding: var(--spacing-lg);
    }

    .app-title {
        font-size: 1.5rem;
    }

    .title-icon {
        font-size: 1.7rem;
    }

    .form-group input {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 14px;
    }

    .btn {
        padding: var(--spacing-md) var(--spacing-lg);
        font-size: 0.9rem;
    }

    .chat-sidebar {
        width: 200px;
        left: -200px;
    }

    .user-item-name,
    .user-item-status {
        font-size: 0.7rem;
    }

    .emoji-grid {
        grid-template-columns: repeat(auto-fill, minmax(30px, 1fr));
    }

    .emoji-item {
        width: 30px;
        height: 30px;
        font-size: 1rem;
    }
}

/* Landscape Mode */
@media (max-width: 768px) and (orientation: landscape) {
    .auth-section {
        min-height: 100vh;
    }

    .auth-container {
        max-width: 500px;
    }

    .chat-sidebar {
        width: 200px;
        height: 100%;
        border-bottom: none;
        border-right: 2px solid var(--border-color);
        flex-direction: column;
    }

    .sidebar-header {
        border-bottom: 2px solid var(--border-color);
        border-right: none;
    }

    .users-list-container {
        flex: 1;
        overflow-x: hidden;
        overflow-y: auto;
        padding: var(--spacing-md);
    }

    .users-list {
        flex-direction: column;
    }

    .sidebar-footer {
        display: block;
        border-top: 2px solid var(--border-color);
        border-right: none;
    }

    .messages-container {
        max-height: calc(100vh - 200px);
    }
}

/* Print Styles */
@media print {
    .chat-sidebar,
    .chat-header,
    .message-input-area,
    .btn-icon,
    .mobile-toggle {
        display: none;
    }

    .messages-container {
        overflow-y: visible;
    }

    body {
        background-color: white;
    }
}

/* High DPI Displays */
@media (-webkit-min-device-pixel-ratio: 2),
       (min-resolution: 192dpi) {
    .message-bubble,
    .btn,
    .avatar {
        -webkit-font-smoothing: antialiased;
        -moz-osx-font-smoothing: grayscale;
    }
}

/* Touch Device Improvements */
@media (hover: none) and (pointer: coarse) {
    .btn,
    .btn-icon,
    .user-item,
    .emoji-item {
        min-height: 44px;
        min-width: 44px;
    }

    .message-input {
        font-size: 16px;
    }

    .btn-icon {
        padding: var(--spacing-md);
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Dark Mode for System Preference */
@media (prefers-color-scheme: dark) {
    body {
        --text-primary: #ECF0F1;
        --text-secondary: #BDC3C7;
        --bg-white: #1A1A1A;
        --bg-light: #2D2D2D;
        --bg-lighter: #3A3A3A;
        --border-color: #404040;
    }
}

/* Specific Mobile Optimizations */
@media (max-width: 480px) {
    /* Prevent zoom on input focus */
    input,
    select,
    textarea {
        font-size: 16px;
    }

    /* Better touch targets */
    button {
        min-height: 44px;
        min-width: 44px;
    }

    /* Optimized padding for smaller screens */
    .message-bubble {
        padding: var(--spacing-sm) var(--spacing-md);
    }

    .form-group {
        margin-bottom: var(--spacing-md);
    }

    /* Prevent text selection on long press */
    .btn {
        user-select: none;
        -webkit-user-select: none;
    }
}

/* Foldable Device Support */
@media (screen-spanning: single-fold-vertical) {
    .app-container {
        margin-left: env(viewport-segment-width 0 0);
        margin-right: env(viewport-segment-width 1 0);
    }

    .chat-sidebar {
        width: 30%;
    }

    .chat-main {
        flex: 1;
    }
}

/* Width Breakpoints - Tablets (750px - 1024px) */
@media (min-width: 750px) and (max-width: 1024px) {
    .chat-sidebar {
        width: 250px;
    }

    .message-content {
        max-width: 75%;
    }

    .auth-container {
        max-width: 450px;
    }
}

/* Width Breakpoints - Small Desktops (1025px - 1440px) */
@media (min-width: 1025px) and (max-width: 1440px) {
    .chat-sidebar {
        width: 280px;
    }

    .message-content {
        max-width: 70%;
    }

    .modal-content {
        max-width: 450px;
    }
}

/* Width Breakpoints - Large Desktops (1441px+) */
@media (min-width: 1441px) {
    .chat-sidebar {
        width: 320px;
    }

    .message-content {
        max-width: 60%;
    }

    .modal-content {
        max-width: 600px;
    }

    .auth-container {
        max-width: 500px;
    }
}