/* CSS Variables */
:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --background: #0f172a;
    --surface: #1e293b;
    --surface-light: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: #334155;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -4px rgba(0, 0, 0, 0.2);
    --radius: 12px;
    --radius-sm: 8px;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* App Container */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--surface) 0%, var(--background) 100%);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.api-status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--surface);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--warning-color);
    animation: pulse 2s infinite;
}

.api-status.online .status-dot {
    background: var(--success-color);
    animation: none;
}

.api-status.offline .status-dot {
    background: var(--danger-color);
    animation: none;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal-overlay.hidden {
    display: none;
}

.modal {
    background: var(--surface);
    border-radius: var(--radius);
    width: 100%;
    max-width: 420px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.modal-header {
    padding: 1.5rem;
    text-align: center;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
}

.modal-header h2 {
    font-size: 1.25rem;
    margin-bottom: 0.25rem;
}

.modal-header p {
    font-size: 0.875rem;
    opacity: 0.9;
}

.modal-body {
    padding: 1.5rem;
}

.input-group {
    margin-bottom: 1rem;
}

.input-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.input-group input {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.input-group input::placeholder {
    color: var(--text-muted);
}

.error-message {
    color: var(--danger-color);
    font-size: 0.875rem;
    margin-top: 0.75rem;
    text-align: center;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    width: 100%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: var(--surface-light);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

/* Main Content */
.main-content {
    flex: 1;
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
    width: 100%;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--surface);
    border-radius: var(--radius);
    padding: 1.25rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    border: 1px solid var(--border-color);
    transition: transform 0.2s, box-shadow 0.2s;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

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

.stat-info {
    display: flex;
    flex-direction: column;
}

.stat-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Events Section */
.events-section {
    background: var(--surface);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.section-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
}

/* Events Grid */
.events-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1rem;
    padding: 1.5rem;
}

/* Event Card */
.event-card {
    background: var(--background);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;
}

.event-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.event-card.closed {
    opacity: 0.7;
}

.event-header {
    padding: 1rem 1.25rem;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
}

.event-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1.4;
}

.event-status {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    white-space: nowrap;
}

.event-status.available {
    background: rgba(16, 185, 129, 0.15);
    color: var(--success-color);
}

.event-status.closed {
    background: rgba(239, 68, 68, 0.15);
    color: var(--danger-color);
}

.event-body {
    padding: 0 1.25rem 1.25rem;
}

.event-dates {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.date-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.35rem 0.75rem;
    background: var(--surface);
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.event-details {
    display: grid;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.detail-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
}

.detail-row svg {
    width: 16px;
    height: 16px;
    color: var(--text-muted);
    flex-shrink: 0;
}

.detail-row span {
    color: var(--text-secondary);
}

.detail-row strong {
    color: var(--text-primary);
    font-weight: 500;
}

.event-times {
    background: var(--surface);
    border-radius: var(--radius-sm);
    padding: 0.75rem;
    margin-bottom: 1rem;
}

.time-slot {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0;
    font-size: 0.8rem;
}

.time-slot:not(:last-child) {
    border-bottom: 1px solid var(--border-color);
}

.time-slot .time {
    color: var(--primary-color);
    font-weight: 500;
}

.time-slot .place {
    color: var(--text-secondary);
}

.event-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    cursor: pointer;
    transition: background-color 0.2s;
    margin: 0 -0.5rem;
    padding-left: 0.5rem;
    padding-right: 0.5rem;
    border-radius: var(--radius-sm);
}

.event-footer:hover {
    background-color: rgba(99, 102, 241, 0.1);
}

.participants {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.participants-avatars {
    display: flex;
}

.avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    font-weight: 600;
    color: white;
    margin-left: -8px;
    border: 2px solid var(--background);
}

.avatar:first-child {
    margin-left: 0;
}

.avatar.more {
    background: var(--surface-light);
    color: var(--text-secondary);
}

.participants-count {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.spots-info {
    text-align: right;
}

.spots-available {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--success-color);
}

.spots-available.full {
    color: var(--danger-color);
}

.spots-total {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.event-note {
    margin-top: 0.75rem;
    padding: 0.5rem 0.75rem;
    background: rgba(245, 158, 11, 0.1);
    border-left: 3px solid var(--warning-color);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    font-size: 0.8rem;
    color: var(--warning-color);
}

/* Loading State */
.loading-state {
    grid-column: 1 / -1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}

.loading-state.hidden {
    display: none;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

/* Empty State */
.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}

.empty-state svg {
    width: 64px;
    height: 64px;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

/* Footer */
.footer {
    text-align: center;
    padding: 1.5rem;
    color: var(--text-muted);
    font-size: 0.875rem;
    border-top: 1px solid var(--border-color);
}

/* Participants Modal */
.participants-modal {
    max-width: 500px;
}

.participants-modal .modal-header h2 {
    font-size: 1.1rem;
}

.participants-list {
    list-style: none;
    max-height: 300px;
    overflow-y: auto;
}

.participants-list li {
    padding: 0.75rem 1rem;
    background: var(--background);
    border-radius: var(--radius-sm);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.participants-list li::before {
    content: '👤';
    font-size: 1rem;
}

.participants-list li.no-participants {
    color: var(--text-muted);
    font-style: italic;
    justify-content: center;
}

.participants-list li.no-participants::before {
    content: '—';
}

.modal-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
}

/* Responsive */
@media (max-width: 768px) {
    .header {
        padding: 1rem;
    }

    .logo {
        font-size: 1.25rem;
    }

    .main-content {
        padding: 1rem;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .events-grid {
        grid-template-columns: 1fr;
        padding: 1rem;
    }

    .section-header {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
    }

    .btn-secondary {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }

    .stat-card {
        padding: 1rem;
    }

    .stat-value {
        font-size: 1.5rem;
    }
}