/* Modern Variables */
:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #1f2937;
    --danger-color: #ef4444;
    --success-color: #10b981;
    --text-primary: #ffffff;
    --text-secondary: #9ca3af;
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-hover: #374151;
    --border-color: #374151;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* Header Styles */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* Button Styles */
.create-group-btn, .logout-btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 0.5rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.875rem;
}

.create-group-btn {
    background-color: var(--primary-color);
    color: var(--text-primary);
    margin-right: 0.75rem;
}

.create-group-btn:hover {
    background-color: var(--primary-hover);
}

.logout-btn {
    background-color: var(--danger-color);
    color: var(--text-primary);
}

.logout-btn:hover {
    background-color: #dc2626;
}

/* Main Container Styles */
.user-list {
    max-width: 800px;
    margin: 0 auto;
    padding: 1.5rem;
}

/* Section Title Styles */
.section-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin: 1.5rem 0 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* User and Group Item Styles */
.user-item, .group-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    background-color: var(--bg-secondary);
    border-radius: 0.75rem;
    margin-bottom: 0.5rem;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
}

.user-item:hover, .group-item:hover {
    background-color: var(--bg-hover);
    border-color: var(--border-color);
    transform: translateY(-1px);
}

/* User Info Styles */
.user-info, .group-info {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex: 1;
}

/* Profile Image Styles */
.profile-image {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--border-color);
}

.default-profile {
    background-color: var(--primary-color);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 1rem;
}

/* Status Container Styles */
.status-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

/* Online Status Dot */
.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--text-secondary);
    position: relative;
}

.online .status-dot {
    background-color: var(--success-color);
    box-shadow: 0 0 0 2px var(--bg-secondary),
                0 0 0 4px rgba(16, 185, 129, 0.2);
}

/* Username Styles */
.user-name, .group-name {
    font-weight: 500;
    color: var(--text-primary);
}

/* Group Members Text */
.group-members {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

/* Unread Badge Styles */
.unread-badge {
    background-color: var(--primary-color);
    color: var(--text-primary);
    padding: 0.25rem 0.625rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
    min-width: 1.5rem;
    text-align: center;
}

.unread {
    background-color: rgba(79, 70, 229, 0.1);
}

/* Loading State */
.loading {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* Error Message */
.error {
    color: var(--danger-color);
    text-align: center;
    padding: 1rem;
    background-color: rgba(239, 68, 68, 0.1);
    border-radius: 0.5rem;
    margin: 1rem 0;
}

/* Responsive Design */
@media (max-width: 640px) {
    .header {
        padding: 1rem;
    }

    .user-list {
        padding: 1rem;
    }

    .create-group-btn, .logout-btn {
        padding: 0.375rem 0.75rem;
        font-size: 0.75rem;
    }

    .profile-image {
        width: 32px;
        height: 32px;
    }

    .user-item, .group-item {
        padding: 0.625rem 0.75rem;
    }

    .group-members {
        display: none;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.user-item, .group-item {
    animation: fadeIn 0.3s ease-out;
}

/* Scrollbar Styles */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-hover);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-color);
}