/* StudyCollab - Modern Dashboard CSS */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: #f8fafc;
    color: #334155;
    line-height: 1.6;
}

/* Header Navigation */
.header {
    background: white;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 0 2rem;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: #3b82f6;
    text-decoration: none;
}

.logo-icon {
    width: 32px;
    height: 32px;
    background: #3b82f6;
    border-radius: 8px;
    margin-right: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: #64748b;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: all 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: #3b82f6;
    background: #eff6ff;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: #e2e8f0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: #64748b;
}

/* Main Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.page-header {
    margin-bottom: 2rem;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 0.5rem;
}

.page-subtitle {
    color: #64748b;
    font-size: 1.1rem;
}

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

/* Metric Cards */
.metric-card {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    border-left: 4px solid;
    transition: all 0.2s;
    position: relative;
    overflow: hidden;
}

.metric-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.metric-card.blue {
    border-left-color: #3b82f6;
}

.metric-card.green {
    border-left-color: #10b981;
}

.metric-card.orange {
    border-left-color: #f59e0b;
}

.metric-card.purple {
    border-left-color: #8b5cf6;
}

.metric-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.metric-icon {
    width: 48px;
    height: 48px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
}

.metric-icon.blue { background: #3b82f6; }
.metric-icon.green { background: #10b981; }
.metric-icon.orange { background: #f59e0b; }
.metric-icon.purple { background: #8b5cf6; }

.metric-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1e293b;
    line-height: 1;
}

.metric-label {
    color: #64748b;
    font-size: 0.9rem;
    margin-top: 0.25rem;
}

.metric-action {
    color: #3b82f6;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    margin-top: 0.75rem;
    transition: color 0.2s;
}

.metric-action:hover {
    color: #2563eb;
}

/* Content Sections */
.content-section {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    margin-bottom: 1.5rem;
}

.section-header {
    display: flex;
    justify-content: between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid #e2e8f0;
}

.section-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1e293b;
}

.view-all-link {
    color: #3b82f6;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
}

.view-all-link:hover {
    color: #2563eb;
}

/* Forms */
.form-container {
    max-width: 400px;
    margin: 2rem auto;
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #374151;
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    justify-content: center;
}

.btn-primary {
    background: #3b82f6;
    color: white;
}

.btn-primary:hover {
    background: #2563eb;
    transform: translateY(-1px);
}

.btn-secondary {
    background: #f1f5f9;
    color: #475569;
}

.btn-secondary:hover {
    background: #e2e8f0;
}

.btn-danger {
    background: #ef4444;
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}

.btn-full {
    width: 100%;
}

/* Group Cards */
.groups-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.group-card {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    transition: all 0.2s;
    border: 1px solid #e2e8f0;
}

.group-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.group-name {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 0.5rem;
}

.group-description {
    color: #64748b;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.group-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    color: #64748b;
    margin-bottom: 1rem;
}

.group-type {
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 500;
}

.group-type.public {
    background: #dcfce7;
    color: #166534;
}

.group-type.private {
    background: #fef3c7;
    color: #92400e;
}

/* Chat Interface */
.chat-container {
    height: 600px;
    display: flex;
    flex-direction: column;
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
    background: #f8fafc;
}

.message {
    margin-bottom: 1rem;
    display: flex;
    gap: 0.75rem;
}

.message-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: #e2e8f0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 600;
    color: #64748b;
    flex-shrink: 0;
}

.message-content {
    flex: 1;
}

.message-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.25rem;
}

.message-author {
    font-weight: 600;
    color: #1e293b;
    font-size: 0.9rem;
}

.message-time {
    font-size: 0.8rem;
    color: #64748b;
}

.message-text {
    background: white;
    padding: 0.75rem 1rem;
    border-radius: 0 12px 12px 12px;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.message.own .message-text {
    background: #3b82f6;
    color: white;
    border-radius: 12px 0 12px 12px;
}

.chat-input-container {
    padding: 1rem;
    border-top: 1px solid #e2e8f0;
    background: white;
}

.chat-input-form {
    display: flex;
    gap: 0.75rem;
}

.chat-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 1px solid #d1d5db;
    border-radius: 24px;
    outline: none;
    transition: border-color 0.2s;
}

.chat-input:focus {
    border-color: #3b82f6;
}

.chat-send-btn {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: #3b82f6;
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
}

.chat-send-btn:hover {
    background: #2563eb;
}

/* Typing Indicator */
.typing-indicator {
    padding: 0.5rem 1rem;
    font-style: italic;
    color: #64748b;
    font-size: 0.9rem;
}

/* Tabs */
.tabs {
    display: flex;
    border-bottom: 1px solid #e2e8f0;
    background: white;
    border-radius: 12px 12px 0 0;
}

.tab {
    padding: 1rem 1.5rem;
    border: none;
    background: none;
    cursor: pointer;
    font-weight: 500;
    color: #64748b;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
}

.tab.active {
    color: #3b82f6;
    border-bottom-color: #3b82f6;
}

.tab-content {
    padding: 1.5rem;
    background: white;
    border-radius: 0 0 12px 12px;
}

/* File Upload */
.file-upload {
    border: 2px dashed #d1d5db;
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    transition: border-color 0.2s;
    cursor: pointer;
}

.file-upload:hover {
    border-color: #3b82f6;
}

.file-upload.dragover {
    border-color: #3b82f6;
    background: #eff6ff;
}

/* Document List */
.document-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.document-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: #f8fafc;
    border-radius: 8px;
    transition: background 0.2s;
}

.document-item:hover {
    background: #f1f5f9;
}

.document-icon {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    background: #3b82f6;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

.document-info {
    flex: 1;
}

.document-name {
    font-weight: 500;
    color: #1e293b;
    margin-bottom: 0.25rem;
}

.document-meta {
    font-size: 0.8rem;
    color: #64748b;
}

/* Calendar */
.calendar {
    background: white;
    border-radius: 12px;
    overflow: hidden;
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background: #f8fafc;
    border-bottom: 1px solid #e2e8f0;
}

.calendar-nav {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 6px;
    transition: background 0.2s;
}

.calendar-nav:hover {
    background: #e2e8f0;
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
}

.calendar-day {
    aspect-ratio: 1;
    padding: 0.5rem;
    border: 1px solid #e2e8f0;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    min-height: 80px;
}

.calendar-day-number {
    font-weight: 500;
    color: #1e293b;
}

.calendar-event {
    background: #3b82f6;
    color: white;
    padding: 0.125rem 0.25rem;
    border-radius: 4px;
    font-size: 0.7rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Alerts */
.alert {
    padding: 1rem 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.alert-success {
    background: #dcfce7;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-info {
    background: #dbeafe;
    color: #1e40af;
    border: 1px solid #bfdbfe;
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
    
    .nav-links {
        display: none;
    }
    
    .groups-grid {
        grid-template-columns: 1fr;
    }
    
    .chat-container {
        height: 500px;
    }
}

/* Loading */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(59, 130, 246, 0.3);
    border-radius: 50%;
    border-top-color: #3b82f6;
    animation: spin 1s ease-in-out infinite;
}

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

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal-content {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.modal-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1e293b;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #64748b;
    padding: 0.25rem;
}

.modal-close:hover {
    color: #374151;
}