:root {
    --bg-color: #f4f7f6;
    --card-bg: #ffffff;
    --text-color: #333;
    --primary: #3498db;
    --accent: #2ecc71;
    --danger: #e74c3c;
    --shadow: 0 4px 6px rgba(0,0,0,0.1);
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --card-bg: #2d2d2d;
    --text-color: #f1f1f1;
    --shadow: 0 4px 10px rgba(0,0,0,0.5);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    transition: all 0.3s ease;
}

.container { max-width: 1000px; margin: auto; padding: 20px; }

header {
    display: flex;
    justify-content: space-between;
    padding: 20px 5%;
    background: var(--card-bg);
    box-shadow: var(--shadow);
}

.dashboard {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.card {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    text-align: center;
}

.stat p { font-size: 2rem; font-weight: bold; margin: 10px 0; color: var(--primary); }

.sensors-grid {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
    justify-content: center;
}

.sensor-mini {
    background: var(--primary);
    color: white;
    padding: 10px 20px;
    border-radius: 20px;
    font-size: 0.9rem;
}

.devices-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.device-card {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 15px;
    border-left: 5px solid #ccc;
    position: relative;
    transition: transform 0.2s;
}

.device-card.active { border-left-color: var(--accent); }

.device-card h4 { margin: 0; }

.btn-toggle {
    margin-top: 15px;
    padding: 8px 15px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

.btn-add {
    display: block;
    width: 100%;
    margin-top: 20px;
    padding: 15px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
}

.history-section { margin-top: 40px; }

.table-container {
    background: var(--card-bg);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
}

table { width: 100%; border-collapse: collapse; }
th, td { padding: 12px; text-align: left; border-bottom: 1px solid #eee; }

.modal {
    display: none;
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.5);
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 12px;
    width: 90%;
    max-width: 400px;
}

input, select {
    width: 100%;
    padding: 10px;
    margin: 10px 0;
    border-radius: 5px;
    border: 1px solid #ccc;
}

footer {
    text-align: center;
    padding: 40px;
    font-weight: bold;
    color: #888;
}