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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background: linear-gradient(135deg, #ffffff 100%);
    min-height: 100vh;
    color: #333;
}

.navbar {
  padding-bottom: 1rem; /* tambah ruang kosong di bawah */
}

html {
  scroll-behavior: smooth;
}

header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 2rem 0;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

header h1 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
    font-size: 2.5rem;
}

.last-update {
    color: #7f8c8d;
    font-size: 0.9rem;
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.card h2 {
    color: #2c3e50;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.value-item {
    background: linear-gradient(135deg, #3498db, #2980b9);
    color: white;
    padding: 1rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.value-item .label {
    display: block;
    font-size: 0.8rem;
    opacity: 0.8;
    margin-bottom: 0.5rem;
}

.value-item .value {
    display: block;
    font-size: 2rem;
    font-weight: bold;
    margin-bottom: 0.25rem;
}

.value-item .unit {
    font-size: 0.9rem;
    opacity: 0.8;
}

.charts canvas {
    max-height: 300px;
}

.controls {
    text-align: center;
}

.control-buttons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

#refreshBtn {
    background: linear-gradient(135deg, #27ae60, #2ecc71);
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
}

#refreshBtn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

#timeRange {
    padding: 0.8rem;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    background: white;
}

footer {
    text-align: center;
    padding: 2rem 0;
    color: rgba(255, 255, 255, 0.8);
    margin-top: 2rem;
}

.loading {
    text-align: center;
    padding: 2rem;
    color: #7f8c8d;
}

.error {
    background: #e74c3c;
    color: white;
    padding: 1rem;
    border-radius: 8px;
    margin: 1rem 0;
    text-align: center;
}

/* Responsive Design */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.8rem;
    }
    
    .control-buttons {
        flex-direction: column;
    }
    
    .values-grid {
        grid-template-columns: 1fr;
    }
}

/* Loading Animation */
.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #3498db;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}