* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.app-container {
    max-width: 500px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    overflow: hidden;
}

.app-header {
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
    color: white;
    padding: 20px;
    text-align: center;
}

.app-header h1 {
    font-size: 24px;
    margin-bottom: 5px;
}

.app-header p {
    font-size: 14px;
    opacity: 0.9;
}

.app-main {
    padding: 20px;
}

.status-card {
    text-align: center;
    margin-bottom: 30px;
}

.status-indicator {
    margin-bottom: 20px;
    padding: 20px;
    border-radius: 15px;
    background: #f8f9fa;
    transition: all 0.3s ease;
}

.status-indicator.present {
    background: #d4edda;
    border: 2px solid #28a745;
}

.status-indicator.absent {
    background: #f8d7da;
    border: 2px solid #dc3545;
}

.status-icon {
    font-size: 48px;
    display: block;
    margin-bottom: 10px;
}

.presence-btn {
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 18px;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(76, 175, 80, 0.3);
    width: 100%;
    max-width: 300px;
}

.presence-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
    box-shadow: none;
}

.presence-btn:not(:disabled):hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(76, 175, 80, 0.4);
}

.btn-icon {
    margin-right: 10px;
}

.info-card, .history-card {
    background: white;
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.info-card h3, .history-card h3 {
    margin-bottom: 15px;
    color: #333;
}

.info-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    padding: 8px 0;
    border-bottom: 1px solid #eee;
}

.info-label {
    font-weight: 500;
    color: #666;
}

.history-list {
    max-height: 300px;
    overflow-y: auto;
}

.history-item {
    padding: 10px;
    border-bottom: 1px solid #eee;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.history-item.present {
    background: #d4edda;
}

.history-item.absent {
    background: #f8d7da;
}

@media (max-width: 600px) {
    .app-container {
        border-radius: 0;
    }
    
    body {
        padding: 0;
    }
}