:root {
    --primary-color: #2563eb;
    --secondary-color: #3b82f6;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

/* Unit Toggle Switch */
.unit-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 1rem;
}

.unit-label {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    transition: color 0.3s;
}

.unit-label.active {
    color: var(--primary-color);
}

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 26px;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--border-color);
    transition: 0.3s;
    border-radius: 26px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 20px;
    width: 20px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: 0.3s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(24px);
}

.dashboard {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.card h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

/* Current Temperature Card */
.current-temp-card {
    text-align: center;
}

.temp-display {
    display: flex;
    align-items: baseline;
    justify-content: center;
    margin: 2rem 0;
}

.temp-value {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
}

.temp-unit {
    font-size: 2rem;
    color: var(--text-secondary);
    margin-left: 0.5rem;
}

.temp-meta {
    margin: 1rem 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.temp-meta p {
    margin: 0.25rem 0;
}

.status {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 1rem;
    padding: 0.5rem;
    background: var(--bg-color);
    border-radius: 6px;
    font-size: 0.9rem;
}

.status-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--text-secondary);
    animation: pulse 2s ease-in-out infinite;
}

.status.connected .status-dot {
    background: var(--success-color);
}

.status.error .status-dot {
    background: var(--danger-color);
}

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

/* Statistics Card */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.stat-item {
    text-align: center;
    padding: 1rem;
    background: var(--bg-color);
    border-radius: 8px;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.stat-value {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--primary-color);
}

/* Chart Card */
.chart-card {
    grid-column: 1 / -1;
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.time-range {
    display: flex;
    gap: 0.5rem;
}

.btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    color: var(--text-primary);
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.875rem;
    transition: all 0.2s;
}

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

.btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.btn-small {
    padding: 0.375rem 0.75rem;
    font-size: 0.8125rem;
}

.chart-container {
    position: relative;
    height: 400px;
}

/* Table Card */
.table-card {
    grid-column: 1 / -1;
}

.table-container {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
}

thead {
    background: var(--bg-color);
}

th {
    padding: 0.75rem;
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

td {
    padding: 0.75rem;
    border-top: 1px solid var(--border-color);
}

tbody tr:hover {
    background: var(--bg-color);
}

.no-data {
    text-align: center;
    color: var(--text-secondary);
    padding: 2rem !important;
}

footer {
    text-align: center;
    margin-top: 3rem;
    padding: 2rem 0;
    color: var(--text-secondary);
    font-size: 0.875rem;
    border-top: 1px solid var(--border-color);
}

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

    header h1 {
        font-size: 2rem;
    }

    .temp-value {
        font-size: 3rem;
    }

    .temp-unit {
        font-size: 1.5rem;
    }

    .dashboard {
        grid-template-columns: 1fr;
    }

    .chart-container {
        height: 300px;
    }

    .chart-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }
}