/**
 * WhatsApp Chat Interface Styles
 * Clean, modern WhatsApp-like design
 */

/* ==========================================
   CSS Variables
   ========================================== */
:root {
    /* Colors - Light Theme */
    --primary-color: #25D366;
    --primary-dark: #128C7E;
    --primary-light: #DCF8C6;
    --secondary-color: #075E54;
    --accent-color: #34B7F1;
    
    /* Background colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f0f2f5;
    --bg-chat: #e5ddd5;
    --bg-sidebar: #ffffff;
    --bg-header: #075E54;
    
    /* Text colors */
    --text-primary: #111b21;
    --text-secondary: #667781;
    --text-light: #ffffff;
    --text-muted: #8696a0;
    
    /* Message colors */
    --msg-sent-bg: #d9fdd3;
    --msg-received-bg: #ffffff;
    --msg-time: #667781;
    
    /* Border colors */
    --border-color: #e9edef;
    --border-light: #f0f2f5;
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.2);
    
    /* Sizes */
    --header-height: 60px;
    --sidebar-width: 360px;
    --input-height: 52px;
    --avatar-size: 49px;
    --avatar-size-sm: 40px;
    
    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-full: 50%;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
}

/* ==========================================
   Reset & Base Styles
   ========================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html, body {
    height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-primary);
    background: var(--bg-secondary);
}

body {
    overflow: hidden;
}

a {
    color: var(--accent-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

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

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

/* ==========================================
   Utility Classes
   ========================================== */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.btn-full {
    width: 100%;
}

.mobile-only {
    display: none;
}

/* ==========================================
   Buttons
   ========================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: var(--radius-md);
    font-weight: 500;
    transition: all var(--transition-fast);
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn-danger {
    background: #dc3545;
    color: white;
}

.btn-danger:hover {
    background: #c82333;
}

.btn-lg {
    padding: 14px 28px;
    font-size: 16px;
}

.btn-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

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

.btn-send {
    width: 52px;
    height: 52px;
    border-radius: var(--radius-full);
    background: var(--primary-color);
    color: white;
    flex-shrink: 0;
}

.btn-send:hover {
    background: var(--primary-dark);
}

/* ==========================================
   Form Elements
   ========================================== */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group small {
    display: block;
    margin-top: 6px;
    color: var(--text-muted);
    font-size: 12px;
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 15px;
    transition: border-color var(--transition-fast);
}

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

.input-with-toggle {
    position: relative;
}

.input-with-toggle .form-input {
    padding-right: 48px;
}

.input-toggle {
    position: absolute;
    right: 4px;
    top: 50%;
    transform: translateY(-50%);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--primary-color);
}

/* ==========================================
   App Container
   ========================================== */
.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-width: 1920px;
    margin: 0 auto;
    background: var(--bg-primary);
    box-shadow: var(--shadow-lg);
}

/* ==========================================
   Header
   ========================================== */
.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-height);
    padding: 0 16px;
    background: var(--bg-header);
    color: var(--text-light);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.header-logo {
    font-size: 32px;
    color: var(--text-light);
}

.header-left h1 {
    font-size: 18px;
    font-weight: 600;
}

.header-center {
    flex: 1;
    max-width: 300px;
    margin: 0 20px;
}

.account-selector {
    width: 100%;
    padding: 8px 12px;
    border: none;
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-light);
    font-size: 14px;
    cursor: pointer;
}

.account-selector:focus {
    outline: none;
    background: rgba(255, 255, 255, 0.2);
}

.account-selector option {
    background: var(--bg-primary);
    color: var(--text-primary);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 8px;
}

.header-right .btn {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-light);
    padding: 8px 16px;
    font-size: 13px;
}

.header-right .btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.header-right .btn-icon {
    color: var(--text-light);
}

.header-right .btn-icon:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-light);
}

/* ==========================================
   Main Content
   ========================================== */
.main-content {
    display: flex;
    flex: 1;
    min-height: 0; /* Important for flexbox overflow */
    overflow: hidden;
}

/* ==========================================
   Sidebar
   ========================================== */
.sidebar {
    display: flex;
    flex-direction: column;
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
}

.search-container {
    position: relative;
    padding: 8px 12px;
    background: var(--bg-secondary);
}

.search-icon {
    position: absolute;
    left: 24px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.search-input {
    width: 100%;
    padding: 10px 16px 10px 40px;
    border: none;
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    font-size: 14px;
}

.search-input:focus {
    outline: none;
}

.sidebar-tabs {
    display: flex;
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 14px 8px;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    transition: all var(--transition-fast);
    border-bottom: 2px solid transparent;
}

.tab-btn:hover {
    background: var(--bg-secondary);
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 20px;
    height: 20px;
    padding: 0 6px;
    border-radius: var(--radius-full);
    background: var(--primary-color);
    color: white;
    font-size: 11px;
    font-weight: 600;
}

.contact-list,
.group-list {
    flex: 1;
    overflow-y: auto;
}

.contact-item,
.group-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    cursor: pointer;
    transition: background var(--transition-fast);
}

.contact-item:hover,
.group-item:hover {
    background: var(--bg-secondary);
}

.contact-item.active,
.group-item.active {
    background: var(--border-light);
}

.contact-avatar,
.group-avatar {
    width: var(--avatar-size);
    height: var(--avatar-size);
    border-radius: var(--radius-full);
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 20px;
    flex-shrink: 0;
}

.contact-info {
    flex: 1;
    min-width: 0;
}

.contact-name {
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.contact-preview {
    font-size: 13px;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-top: 2px;
}

.contact-meta {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 4px;
}

.contact-time {
    font-size: 12px;
    color: var(--text-muted);
}

.contact-unread {
    min-width: 20px;
    height: 20px;
    padding: 0 6px;
    border-radius: var(--radius-full);
    background: var(--primary-color);
    color: white;
    font-size: 11px;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
}

.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    text-align: center;
    color: var(--text-muted);
}

.empty-state i {
    font-size: 48px;
    margin-bottom: 16px;
    opacity: 0.5;
}

.empty-state p {
    font-size: 16px;
    margin-bottom: 4px;
}

.empty-state small {
    font-size: 13px;
}

/* Bulk Panel */
.bulk-panel {
    flex: 1;
    padding: 16px;
    overflow-y: auto;
}

.bulk-header h3 {
    margin-bottom: 16px;
    color: var(--text-primary);
}

.bulk-recipients,
.bulk-message,
.bulk-campaign {
    margin-bottom: 16px;
}

.bulk-panel label {
    display: block;
    margin-bottom: 6px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
}

.bulk-panel textarea,
.bulk-panel input {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 14px;
    resize: none;
}

.bulk-panel textarea {
    min-height: 80px;
}

.bulk-panel textarea:focus,
.bulk-panel input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.new-chat-container {
    padding: 12px;
    border-top: 1px solid var(--border-color);
}

/* ==========================================
   Chat Area
   ========================================== */
.chat-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0; /* Important for flexbox overflow */
    overflow: hidden;
    background: var(--bg-chat);
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23b0b0b0' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.no-chat-selected {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
}

.welcome-message {
    text-align: center;
    color: var(--text-secondary);
}

.welcome-message i {
    font-size: 80px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.welcome-message h2 {
    font-size: 28px;
    font-weight: 300;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.chat-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0; /* Important for flexbox overflow */
    overflow: hidden;
}

.chat-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 16px;
    background: var(--bg-sidebar);
    border-bottom: 1px solid var(--border-color);
}

.chat-avatar {
    width: var(--avatar-size);
    height: var(--avatar-size);
    border-radius: var(--radius-full);
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 20px;
}

.chat-info {
    flex: 1;
}

.chat-info h3 {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-primary);
}

.chat-status {
    font-size: 13px;
    color: var(--text-secondary);
}

.chat-actions {
    display: flex;
    gap: 8px;
}

.messages-container {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
    position: relative;
}

.messages-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.message {
    max-width: 65%;
    padding: 8px 12px;
    border-radius: var(--radius-lg);
    position: relative;
    animation: messageSlide 0.2s ease;
}

@keyframes messageSlide {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message-sent {
    align-self: flex-end;
    background: var(--msg-sent-bg);
    border-bottom-right-radius: var(--radius-sm);
}

.message-received {
    align-self: flex-start;
    background: var(--msg-received-bg);
    border-bottom-left-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
}

.message-content {
    word-wrap: break-word;
    white-space: pre-wrap;
}

.message-media {
    max-width: 300px;
    margin-bottom: 4px;
}

.message-media img,
.message-media video {
    max-width: 100%;
    border-radius: var(--radius-md);
}

.message-document {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px;
    background: rgba(0, 0, 0, 0.05);
    border-radius: var(--radius-md);
    margin-bottom: 4px;
}

.message-document i {
    font-size: 24px;
    color: var(--primary-dark);
}

.message-document-info {
    flex: 1;
}

.message-document-name {
    font-weight: 500;
    font-size: 13px;
}

.message-document-size {
    font-size: 11px;
    color: var(--text-muted);
}

.message-meta {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 4px;
    margin-top: 4px;
}

.message-time {
    font-size: 11px;
    color: var(--msg-time);
}

.message-status {
    font-size: 14px;
    color: var(--accent-color);
}

.message-status.pending {
    color: var(--text-muted);
}

.message-status.sent {
    color: var(--text-muted);
}

.message-status.delivered {
    color: var(--accent-color);
}

.message-status.read {
    color: var(--accent-color);
}

.date-divider {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 16px 0;
}

.date-divider span {
    padding: 6px 16px;
    background: rgba(225, 245, 254, 0.92);
    border-radius: var(--radius-md);
    font-size: 12px;
    color: var(--text-secondary);
    box-shadow: var(--shadow-sm);
}

.scroll-to-bottom {
    position: absolute;
    bottom: 20px;
    right: 20px;
}

.scroll-to-bottom .btn-icon {
    background: var(--bg-primary);
    box-shadow: var(--shadow-md);
}

.loading-messages {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 20px;
    color: var(--text-secondary);
}

/* Input Area */
.input-area {
    display: flex;
    align-items: flex-end;
    gap: 8px;
    padding: 10px 16px;
    background: var(--bg-secondary);
}

.input-actions {
    display: flex;
    gap: 4px;
}

.input-container {
    flex: 1;
    background: var(--bg-primary);
    border-radius: 24px;
    padding: 0 16px;
}

.input-container textarea {
    width: 100%;
    padding: 14px 0;
    border: none;
    background: transparent;
    resize: none;
    max-height: 150px;
    line-height: 1.4;
}

.input-container textarea:focus {
    outline: none;
}

.attachment-preview {
    position: relative;
    padding: 10px 16px;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
}

.preview-content {
    max-width: 200px;
}

.preview-content img {
    max-width: 100%;
    border-radius: var(--radius-md);
}

.preview-content .document-preview {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
}

.btn-remove {
    position: absolute;
    top: 4px;
    right: 20px;
    background: rgba(0, 0, 0, 0.5);
    color: white;
}

.btn-remove:hover {
    background: rgba(0, 0, 0, 0.7);
    color: white;
}

/* ==========================================
   Modals
   ========================================== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
}

.modal-content {
    position: relative;
    width: 90%;
    max-width: 420px;
    max-height: 90vh;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.modal-lg {
    max-width: 520px;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    background: var(--bg-header);
    color: var(--text-light);
}

.modal-header h2 {
    font-size: 18px;
    font-weight: 500;
}

.modal-header .btn-icon {
    color: var(--text-light);
}

.modal-header .btn-icon:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-light);
}

.modal-body {
    padding: 24px 20px;
    overflow-y: auto;
    max-height: 60vh;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    padding: 16px 20px;
    border-top: 1px solid var(--border-color);
}

.qr-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
}

.qr-container img {
    max-width: 256px;
    border-radius: var(--radius-md);
}

.qr-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    padding: 40px;
}

.qr-instructions {
    margin-top: 20px;
    padding: 16px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    text-align: left;
    font-size: 13px;
    line-height: 1.8;
}

.link-status {
    margin-top: 16px;
    padding: 12px;
    border-radius: var(--radius-md);
    font-weight: 500;
}

.link-status.success {
    background: var(--primary-light);
    color: var(--primary-dark);
}

.link-status.error {
    background: #ffebee;
    color: #c62828;
}

.validation-result {
    margin-top: 12px;
    padding: 12px;
    border-radius: var(--radius-md);
    font-size: 13px;
}

.validation-result.valid {
    background: var(--primary-light);
    color: var(--primary-dark);
}

.validation-result.invalid {
    background: #ffebee;
    color: #c62828;
}

/* ==========================================
   Toast Notifications
   ========================================== */
.toast-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.toast {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
    background: var(--text-primary);
    color: var(--text-light);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    animation: toastSlide 0.3s ease;
    max-width: 360px;
}

@keyframes toastSlide {
    from {
        opacity: 0;
        transform: translateX(100%);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.toast.success {
    background: var(--primary-dark);
}

.toast.error {
    background: #dc3545;
}

.toast.warning {
    background: #ffc107;
    color: var(--text-primary);
}

.toast-close {
    margin-left: auto;
    opacity: 0.7;
    cursor: pointer;
}

.toast-close:hover {
    opacity: 1;
}

/* ==========================================
   Spinner
   ========================================== */
.spinner {
    width: 32px;
    height: 32px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: var(--radius-full);
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* ==========================================
   Login Page
   ========================================== */
.login-page {
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--primary-dark) 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.login-container {
    display: flex;
    gap: 40px;
    max-width: 900px;
    width: 100%;
}

.login-card {
    flex: 1;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: 40px;
    max-width: 440px;
}

.login-header {
    text-align: center;
    margin-bottom: 32px;
}

.login-logo {
    font-size: 64px;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.login-header h1 {
    font-size: 24px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.login-header p {
    color: var(--text-secondary);
}

.login-form {
    margin-bottom: 24px;
}

.login-footer {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.login-footer p {
    font-size: 13px;
    color: var(--text-muted);
}

.login-features {
    flex: 1;
    color: var(--text-light);
    padding: 20px;
}

.login-features h2 {
    font-size: 24px;
    margin-bottom: 24px;
}

.login-features ul {
    list-style: none;
}

.login-features li {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 14px 0;
    font-size: 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.login-features li i {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-full);
    font-size: 18px;
}

.error-message {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    background: #ffebee;
    color: #c62828;
    border-radius: var(--radius-md);
    margin-top: 16px;
    font-size: 14px;
}

.loading-message {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 16px;
    color: var(--text-secondary);
    margin-top: 16px;
}

/* ==========================================
   Responsive Styles
   ========================================== */
@media (max-width: 900px) {
    .login-container {
        flex-direction: column;
    }
    
    .login-features {
        display: none;
    }
    
    .login-card {
        max-width: 100%;
    }
}

@media (max-width: 768px) {
    :root {
        --sidebar-width: 100%;
    }
    
    .main-content {
        position: relative;
    }
    
    .sidebar {
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        z-index: 10;
    }
    
    .chat-area {
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
    }
    
    .no-chat-selected {
        display: none;
    }
    
    .chat-container {
        display: none;
    }
    
    .chat-container.active {
        display: flex;
    }
    
    .sidebar.hidden-mobile {
        display: none;
    }
    
    .mobile-only {
        display: flex;
    }
    
    .header-left h1 {
        display: none;
    }
    
    .header-right .btn span {
        display: none;
    }
    
    .message {
        max-width: 85%;
    }
}

@media (max-width: 480px) {
    .app-header {
        padding: 0 10px;
    }
    
    .header-center {
        margin: 0 10px;
    }
    
    .login-card {
        padding: 24px;
    }
    
    .modal-content {
        width: 95%;
        margin: 20px;
    }
    
    .toast-container {
        left: 16px;
        right: 16px;
        bottom: 16px;
    }
    
    .toast {
        max-width: 100%;
    }
}