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

:root {
    --bg: #0f1117;
    --surface: #1a1d27;
    --surface-hover: #242836;
    --border: #2e3348;
    --text: #e4e6f0;
    --text-muted: #8b90a5;
    --primary: #6c8cff;
    --primary-hover: #8ba4ff;
    --danger: #ff6b6b;
    --temp-color: #ff6b6b;
    --humidity-color: #6bc5ff;
    --pressure-color: #a78bfa;
    --battery-ok: #4ade80;
    --battery-warn: #fbbf24;
    --battery-low: #ff6b6b;
    --radius: 12px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
}

/* ---------- Login ---------- */
.login-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 1rem;
}

.login-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2.5rem 2rem;
    width: 100%;
    max-width: 380px;
}

.login-card h1 {
    text-align: center;
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.login-card label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.3rem;
    margin-top: 1rem;
}

.login-card input[type="text"],
.login-card input[type="password"] {
    width: 100%;
    padding: 0.6rem 0.8rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg);
    color: var(--text);
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s;
}

.login-card input:focus {
    border-color: var(--primary);
}

.remember-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
}

.remember-row label {
    margin: 0;
    font-size: 0.9rem;
    color: var(--text);
}

.login-card button {
    width: 100%;
    margin-top: 1.5rem;
    padding: 0.7rem;
    border: none;
    border-radius: 8px;
    background: var(--primary);
    color: #fff;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s;
}

.login-card button:hover {
    background: var(--primary-hover);
}

.flash {
    padding: 0.6rem 0.8rem;
    border-radius: 8px;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.flash-error {
    background: rgba(255, 107, 107, 0.15);
    color: var(--danger);
    border: 1px solid rgba(255, 107, 107, 0.3);
}

/* ---------- Top Bar ---------- */
.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.8rem 1.5rem;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
}

.topbar-title {
    font-size: 1.1rem;
    font-weight: 600;
}

.topbar-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.topbar-actions select {
    background: var(--bg);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.4rem 0.6rem;
    font-size: 0.85rem;
    cursor: pointer;
}

.btn-logout {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.85rem;
    padding: 0.4rem 0.8rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    transition: color 0.2s, border-color 0.2s;
}

.btn-logout:hover {
    color: var(--text);
    border-color: var(--text-muted);
}

/* ---------- Dashboard ---------- */
.dashboard {
    padding: 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

.sensor-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.loading {
    color: var(--text-muted);
    grid-column: 1 / -1;
    text-align: center;
    padding: 2rem;
}

.sensor-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.2rem 1.4rem;
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s;
}

.sensor-card:hover {
    background: var(--surface-hover);
    border-color: var(--primary);
}

.sensor-card.active {
    border-color: var(--primary);
}

.sensor-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.8rem;
}

.sensor-name {
    font-weight: 600;
    font-size: 1rem;
}

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

.sensor-values {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.6rem;
}

.sensor-value {
    display: flex;
    flex-direction: column;
}

.sensor-value .label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.sensor-value .value {
    font-size: 1.3rem;
    font-weight: 600;
}

.sensor-value .value.temp { color: var(--temp-color); }
.sensor-value .value.humidity { color: var(--humidity-color); }
.sensor-value .value.pressure { color: var(--pressure-color); }

.battery-indicator {
    display: flex;
    align-items: center;
    gap: 0.3rem;
    margin-top: 0.6rem;
    font-size: 0.8rem;
}

.battery-indicator .dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.battery-ok .dot { background: var(--battery-ok); }
.battery-warn .dot { background: var(--battery-warn); }
.battery-low .dot { background: var(--battery-low); }

/* ---------- Chart ---------- */
.chart-section {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
}

.chart-section h2 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.chart-container {
    position: relative;
    height: 350px;
}

.hidden {
    display: none;
}

/* ---------- Responsive ---------- */
@media (max-width: 600px) {
    .dashboard {
        padding: 1rem;
    }
    .sensor-grid {
        grid-template-columns: 1fr;
    }
    .chart-container {
        height: 250px;
    }
}