/* ============================================
   Signnet - Professional Social Platform
   Deaf-Friendly Design
   ============================================ */

/* CSS Variables for Theme and Accessibility */
:root {
    /* Colors - High Contrast Default */
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --error-color: #ef4444;
    --success-color: #10b981;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --bg-hover: #f3f4f6;
    
    /* Text Colors - High Contrast */
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    --text-inverse: #ffffff;
    
    /* Border Colors */
    --border-color: #e5e7eb;
    --border-hover: #d1d5db;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 14px;
    --font-size-lg: 18px;
    --font-size-xl: 20px;
    --font-size-2xl: 24px;
    --font-size-3xl: 30px;
    
    /* Line Height - Improved Readability */
    --line-height-base: 1.6;
    --line-height-tight: 1.4;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
    
    /* Focus Indicators - High Visibility */
    --focus-outline: 3px solid var(--primary-color);
    --focus-outline-offset: 2px;
}

/* High Contrast Mode */
body.high-contrast {
    --bg-primary: #ffffff;
    --bg-secondary: #f0f0f0;
    --text-primary: #000000;
    --text-secondary: #333333;
    --border-color: #000000;
    --primary-color: #0066cc;
    --focus-outline: 4px solid #000000;
}

/* Large Font Mode */
body.large-font {
    --font-size-base: 20px;
    --font-size-sm: 18px;
    --font-size-lg: 24px;
    --font-size-xl: 28px;
    --font-size-2xl: 32px;
    --font-size-3xl: 40px;
}

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

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Skip Link for Screen Readers */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: var(--text-inverse);
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    z-index: 1000;
    border-radius: var(--radius-sm);
}

.skip-link:focus {
    top: 0;
}

/* Header Styles */
.header {
    background-color: var(--bg-primary);
    border-bottom: 2px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    gap: var(--spacing-lg);
}

.logo-section {
    display: flex;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: var(--font-size-xl);
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--primary-color);
}

.logo-text {
    font-weight: 700;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    flex: 1;
    justify-content: center;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    position: relative;
    font-weight: 500;
}

.nav-link:hover,
.nav-link:focus {
    background-color: var(--bg-hover);
    color: var(--text-primary);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.nav-link.active {
    color: var(--primary-color);
    background-color: rgba(79, 70, 229, 0.1);
    font-weight: 600;
}

.nav-icon {
    font-size: 1.2em;
}

.notification-badge {
    background-color: var(--error-color);
    color: var(--text-inverse);
    border-radius: 50%;
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 700;
    position: absolute;
    top: -4px;
    right: -4px;
    border: 2px solid var(--bg-primary);
    min-width: 20px;
}

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

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

.btn-primary {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    background-color: var(--primary-color);
    color: var(--text-inverse);
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: var(--font-size-base);
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: inherit;
}

.btn-primary:hover,
.btn-primary:focus {
    background-color: var(--primary-hover);
    outline: var(--focus-outline);
    outline-offset: var(--focus-outline-offset);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.user-menu {
    position: relative;
}

.user-avatar {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: none;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xs);
    cursor: pointer;
    transition: all var(--transition-base);
}

.user-avatar:hover,
.user-avatar:focus {
    border-color: var(--primary-color);
    outline: var(--focus-outline);
    outline-offset: var(--focus-outline-offset);
}

.avatar-img {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
}

.dropdown-arrow {
    font-size: 10px;
    color: var(--text-secondary);
}

.dropdown-menu {
    position: absolute;
    top: calc(100% + var(--spacing-sm));
    right: 0;
    background-color: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    min-width: 200px;
    padding: var(--spacing-sm);
    display: none;
    z-index: 1000;
}

.dropdown-menu[aria-hidden="false"] {
    display: block;
}

.dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    text-decoration: none;
    color: var(--text-primary);
    border-radius: var(--radius-sm);
    transition: all var(--transition-base);
    width: 100%;
}

.dropdown-item:hover,
.dropdown-item:focus {
    background-color: var(--bg-hover);
    outline: 2px solid var(--primary-color);
    outline-offset: -2px;
}

.dropdown-icon {
    font-size: 1.2em;
}

.dropdown-divider {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: var(--spacing-sm) 0;
}

/* Main Content Layout */
.main-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-lg);
}

.content-wrapper {
    display: grid;
    grid-template-columns: 250px 1fr 300px;
    gap: var(--spacing-xl);
}

/* Sidebar Styles */
.sidebar {
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    height: fit-content;
    position: sticky;
    top: 80px;
    border: 1px solid var(--border-color);
}

.sidebar-section {
    margin-bottom: var(--spacing-xl);
}

.sidebar-section:last-child {
    margin-bottom: 0;
}

.sidebar-title {
    font-size: var(--font-size-lg);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    text-decoration: none;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    font-weight: 500;
}

.sidebar-link:hover,
.sidebar-link:focus {
    background-color: var(--bg-hover);
    color: var(--text-primary);
    outline: 2px solid var(--primary-color);
    outline-offset: -2px;
}

.sidebar-link.active {
    background-color: rgba(79, 70, 229, 0.1);
    color: var(--primary-color);
    font-weight: 600;
}

.sidebar-icon {
    font-size: 1.2em;
    width: 24px;
    text-align: center;
}

/* Accessibility Controls */
.accessibility-controls {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.accessibility-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: inherit;
    font-size: var(--font-size-base);
    color: var(--text-primary);
    font-weight: 500;
    width: 100%;
    text-align: left;
}

.accessibility-btn:hover,
.accessibility-btn:focus {
    background-color: var(--bg-hover);
    border-color: var(--primary-color);
    outline: var(--focus-outline);
    outline-offset: var(--focus-outline-offset);
}

.accessibility-btn.active {
    background-color: var(--primary-color);
    color: var(--text-inverse);
    border-color: var(--primary-color);
}

.accessibility-icon {
    font-size: 1.2em;
}

/* Feed Section */
.feed-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* Post Composer */
.post-composer {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    display: none;
    box-shadow: var(--shadow-md);
}

.post-composer.active {
    display: block;
}

.composer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

.composer-title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
}

.close-btn {
    background: none;
    border: none;
    font-size: var(--font-size-xl);
    cursor: pointer;
    color: var(--text-secondary);
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: all var(--transition-base);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.close-btn:hover,
.close-btn:focus {
    background-color: var(--bg-hover);
    color: var(--text-primary);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.composer-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

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

.composer-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
}

.composer-user-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.composer-username {
    font-weight: 600;
    color: var(--text-primary);
}

.composer-visibility {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.composer-textarea {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    resize: vertical;
    min-height: 120px;
    color: var(--text-primary);
    background-color: var(--bg-primary);
}

.composer-textarea:focus {
    outline: var(--focus-outline);
    outline-offset: var(--focus-outline-offset);
    border-color: var(--primary-color);
}

.composer-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.composer-tools {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.tool-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: inherit;
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    font-weight: 500;
}

.tool-btn:hover,
.tool-btn:focus {
    background-color: var(--bg-hover);
    border-color: var(--primary-color);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.tool-icon {
    font-size: 1.2em;
}

.composer-preview {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border-radius: var(--radius-md);
    display: none;
}

.composer-preview.active {
    display: block;
}

/* Post Cards */
.feed-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.post-card {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.post-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--border-hover);
}

.post-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

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

.post-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--border-color);
}

.post-author-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.post-author-name {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--text-primary);
}

.post-time {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.post-menu-btn {
    background: none;
    border: none;
    font-size: var(--font-size-xl);
    cursor: pointer;
    color: var(--text-secondary);
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: all var(--transition-base);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.post-menu-btn:hover,
.post-menu-btn:focus {
    background-color: var(--bg-hover);
    color: var(--text-primary);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.post-content {
    margin-bottom: var(--spacing-md);
}

.post-text {
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    white-space: pre-wrap;
    word-wrap: break-word;
}

.post-media {
    margin-top: var(--spacing-md);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.post-image {
    width: 100%;
    height: auto;
    display: block;
    border-radius: var(--radius-md);
}

.video-container {
    position: relative;
    width: 100%;
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.post-video {
    width: 100%;
    height: auto;
    display: block;
    border-radius: var(--radius-md);
}

.video-captions {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.8);
    color: var(--text-inverse);
    padding: var(--spacing-md);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    max-height: 150px;
    overflow-y: auto;
}

.caption-text {
    color: var(--text-inverse);
    font-weight: 500;
}

.sign-language-video {
    position: relative;
}

.sign-language-badge {
    position: absolute;
    top: var(--spacing-md);
    left: var(--spacing-md);
    background-color: var(--primary-color);
    color: var(--text-inverse);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    z-index: 10;
    font-weight: 600;
    font-size: var(--font-size-sm);
    box-shadow: var(--shadow-md);
}

.badge-icon {
    font-size: 1.2em;
}

.post-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

.action-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    font-family: inherit;
    font-size: var(--font-size-base);
    color: var(--text-secondary);
    font-weight: 500;
}

.action-btn:hover,
.action-btn:focus {
    background-color: var(--bg-hover);
    color: var(--text-primary);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
    transform: scale(1.05);
}

.action-btn.liked {
    color: var(--error-color);
}

.action-icon {
    font-size: 1.2em;
}

.action-count {
    font-weight: 600;
}

/* Trending Section */
.trending-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.trending-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    text-decoration: none;
    color: var(--text-primary);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.trending-item:hover,
.trending-item:focus {
    background-color: var(--bg-hover);
    outline: 2px solid var(--primary-color);
    outline-offset: -2px;
}

.trending-number {
    font-weight: 700;
    font-size: var(--font-size-lg);
    color: var(--primary-color);
    min-width: 24px;
}

.trending-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    flex: 1;
}

.trending-topic {
    font-weight: 600;
    color: var(--text-primary);
}

.trending-count {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

/* Community Section */
.community-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.community-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    text-decoration: none;
    color: var(--text-primary);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.community-item:hover,
.community-item:focus {
    background-color: var(--bg-hover);
    border-color: var(--primary-color);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.community-avatar {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background-color: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5em;
    flex-shrink: 0;
}

.community-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    flex: 1;
}

.community-name {
    font-weight: 600;
    color: var(--text-primary);
}

.community-members {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.join-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--primary-color);
    color: var(--text-inverse);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 600;
    font-size: var(--font-size-sm);
    transition: all var(--transition-base);
    font-family: inherit;
}

.join-btn:hover,
.join-btn:focus {
    background-color: var(--primary-hover);
    outline: var(--focus-outline);
    outline-offset: var(--focus-outline-offset);
    transform: translateY(-1px);
}

/* Notification System */
.notification-container {
    position: fixed;
    top: 80px;
    right: var(--spacing-lg);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    max-width: 400px;
}

.notification {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-left: 4px solid var(--primary-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    animation: slideIn 0.3s ease;
    min-width: 300px;
}

.notification.success {
    border-left-color: var(--success-color);
}

.notification.error {
    border-left-color: var(--error-color);
}

.notification-icon {
    font-size: 1.5em;
    flex-shrink: 0;
}

.notification-content {
    flex: 1;
}

.notification-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.notification-message {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

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

/* Authentication Modal */
.auth-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 10000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.auth-modal[aria-hidden="false"] {
    display: flex;
}

.auth-modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.auth-modal-content {
    position: relative;
    background-color: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 480px;
    max-height: 90vh;
    overflow-y: auto;
    padding: var(--spacing-2xl);
    z-index: 1;
    animation: modalSlideIn 0.3s ease;
}

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

.auth-close-btn {
    position: absolute;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    background: none;
    border: none;
    font-size: var(--font-size-xl);
    cursor: pointer;
    color: var(--text-secondary);
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: all var(--transition-base);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
}

.auth-close-btn:hover,
.auth-close-btn:focus {
    background-color: var(--bg-hover);
    color: var(--text-primary);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.auth-tabs {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xl);
    border-bottom: 2px solid var(--border-color);
}

.auth-tab {
    flex: 1;
    padding: var(--spacing-md) var(--spacing-lg);
    background: none;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-family: inherit;
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--text-secondary);
    transition: all var(--transition-base);
    position: relative;
    bottom: -2px;
}

.auth-tab:hover,
.auth-tab:focus {
    color: var(--text-primary);
    outline: 2px solid var(--primary-color);
    outline-offset: -2px;
}

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

.auth-panel {
    display: none;
}

.auth-panel.active {
    display: block;
}

.auth-panel[aria-hidden="true"] {
    display: none;
}

.auth-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    text-align: center;
}

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

.social-login {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.social-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: inherit;
    font-size: var(--font-size-base);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    width: 100%;
}

.social-btn:hover,
.social-btn:focus {
    background-color: var(--bg-hover);
    border-color: var(--primary-color);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.social-icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

.google-btn:hover {
    border-color: #4285F4;
    background-color: rgba(66, 133, 244, 0.05);
}

.apple-btn:hover {
    border-color: #000000;
    background-color: rgba(0, 0, 0, 0.05);
}

.x-btn:hover {
    border-color: #000000;
    background-color: rgba(0, 0, 0, 0.05);
}

.auth-divider {
    display: flex;
    align-items: center;
    text-align: center;
    margin: var(--spacing-xl) 0;
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

.auth-divider::before,
.auth-divider::after {
    content: '';
    flex: 1;
    border-bottom: 1px solid var(--border-color);
}

.auth-divider span {
    padding: 0 var(--spacing-md);
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.form-label {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--text-primary);
}

.form-input {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: var(--font-size-base);
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: all var(--transition-base);
}

.form-input:focus {
    outline: var(--focus-outline);
    outline-offset: var(--focus-outline-offset);
    border-color: var(--primary-color);
}

.form-input:invalid:not(:placeholder-shown) {
    border-color: var(--error-color);
}

.form-error {
    font-size: var(--font-size-sm);
    color: var(--error-color);
    min-height: 20px;
    display: block;
}

.password-input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.password-input-wrapper .form-input {
    padding-right: 45px;
}

.password-toggle {
    position: absolute;
    right: var(--spacing-sm);
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    color: var(--text-secondary);
    font-size: var(--font-size-lg);
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
}

.password-toggle:hover,
.password-toggle:focus {
    background-color: var(--bg-hover);
    color: var(--text-primary);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.password-strength {
    margin-top: var(--spacing-xs);
}

.password-strength-bar {
    height: 4px;
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin-bottom: var(--spacing-xs);
}

.password-strength-fill {
    height: 100%;
    width: 0%;
    background-color: var(--error-color);
    transition: all var(--transition-base);
}

.password-strength-fill.weak {
    width: 33%;
    background-color: var(--error-color);
}

.password-strength-fill.medium {
    width: 66%;
    background-color: var(--accent-color);
}

.password-strength-fill.strong {
    width: 100%;
    background-color: var(--success-color);
}

.password-strength-text {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.form-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    cursor: pointer;
}

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

.checkbox-label a {
    color: var(--primary-color);
    text-decoration: none;
}

.checkbox-label a:hover,
.checkbox-label a:focus {
    text-decoration: underline;
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.forgot-link {
    font-size: var(--font-size-sm);
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.forgot-link:hover,
.forgot-link:focus {
    text-decoration: underline;
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.btn-auth-submit {
    width: 100%;
    justify-content: center;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-base);
    margin-top: var(--spacing-md);
}

.btn-auth-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Footer */
.footer {
    background-color: var(--bg-primary);
    border-top: 2px solid var(--border-color);
    margin-top: var(--spacing-2xl);
    padding: var(--spacing-2xl) var(--spacing-lg);
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
}

.footer-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.footer-title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
}

.footer-description {
    color: var(--text-secondary);
    line-height: var(--line-height-base);
}

.footer-heading {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.footer-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-base);
}

.footer-links a:hover,
.footer-links a:focus {
    color: var(--primary-color);
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.footer-bottom {
    max-width: 1400px;
    margin: var(--spacing-xl) auto 0;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 1200px) {
    .content-wrapper {
        grid-template-columns: 200px 1fr 250px;
    }
}

@media (max-width: 968px) {
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        position: static;
    }
    
    .sidebar-left {
        order: 2;
    }
    
    .feed-section {
        order: 1;
    }
    
    .sidebar-right {
        order: 3;
    }
    
    .nav-links {
        display: none;
    }
    
    .user-section {
        margin-left: auto;
    }
}

@media (max-width: 640px) {
    .nav-content {
        padding: 0 var(--spacing-md);
    }
    
    .main-container {
        padding: var(--spacing-md);
    }
    
    .post-composer,
    .post-card {
        padding: var(--spacing-md);
    }
    
    .composer-actions {
        flex-direction: column;
        align-items: stretch;
    }
    
    .composer-tools {
        justify-content: space-between;
    }
    
    .tool-text {
        display: none;
    }
    
    /* Auth Modal Mobile */
    .auth-modal {
        padding: var(--spacing-sm);
    }
    
    .auth-modal-content {
        padding: var(--spacing-xl) var(--spacing-lg);
        max-height: 95vh;
    }
    
    .auth-title {
        font-size: var(--font-size-xl);
    }
    
    .social-btn {
        font-size: var(--font-size-sm);
        padding: var(--spacing-sm) var(--spacing-md);
    }
}

/* Print Styles */
@media print {
    .header,
    .sidebar,
    .footer,
    .post-actions,
    .notification-container {
        display: none;
    }
    
    .content-wrapper {
        grid-template-columns: 1fr;
    }
}