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

/* Theme variables */
:root {
    --bg: #f0f2f5;
    --text: #1a1a2e;
    --card-bg: #fff;
    --card-shadow: rgba(0,0,0,0.08);
    --header-bg: #003f5c;
    --header-text: #fff;
    --login-bg: linear-gradient(135deg, #003f5c 0%, #2f4b7c 100%);
    --login-card: #fff;
    --login-title: #003f5c;
    --input-bg: #fff;
    --input-border: #ccc;
    --input-text: #1a1a2e;
    --chart-title: #003f5c;
    --error-bg: #fee;
    --error-text: #c00;
}

[data-theme="dark"] {
    --bg: #1a1a2e;
    --text: #e0e0e0;
    --card-bg: #252540;
    --card-shadow: rgba(0,0,0,0.3);
    --header-bg: #0d0d1a;
    --header-text: #e0e0e0;
    --login-bg: linear-gradient(135deg, #0d0d1a 0%, #1a1a2e 100%);
    --login-card: #252540;
    --login-title: #7eb8da;
    --input-bg: #1a1a2e;
    --input-border: #444;
    --input-text: #e0e0e0;
    --chart-title: #7eb8da;
    --error-bg: #3a1a1a;
    --error-text: #ff6b6b;
}

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

[hidden] {
    display: none !important;
}

/* Login */
.login-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: var(--login-bg);
}

.login-form {
    background: var(--login-card);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.15);
    width: 100%;
    max-width: 360px;
}

.login-form h1 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    text-align: center;
    color: var(--login-title);
}

.login-form input {
    display: block;
    width: 100%;
    padding: 0.75rem;
    margin-bottom: 1rem;
    border: 1px solid var(--input-border);
    border-radius: 4px;
    font-size: 1rem;
    background: var(--input-bg);
    color: var(--input-text);
}

.login-form button {
    width: 100%;
    padding: 0.75rem;
    background: #003f5c;
    color: #fff;
    border: none;
    border-radius: 4px;
    font-size: 1rem;
    cursor: pointer;
}

.login-form button:hover {
    background: #2f4b7c;
}

.login-error {
    background: var(--error-bg);
    color: var(--error-text);
    padding: 0.5rem;
    border-radius: 4px;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    text-align: center;
}

/* Dashboard */
.dashboard {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--header-bg);
    color: var(--header-text);
    padding: 0.75rem 1rem;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.75rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.header h1 {
    font-size: 1.1rem;
    white-space: nowrap;
}

.header-controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem;
    margin-left: auto;
}

.date-controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem;
}

.date-controls label {
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.date-controls input {
    padding: 0.3rem 0.4rem;
    border: none;
    border-radius: 4px;
    font-size: 0.8rem;
    background: var(--input-bg);
    color: var(--input-text);
}

.presets {
    display: flex;
    gap: 0.25rem;
}

.preset-select {
    display: none;
    padding: 0.35rem 0.5rem;
    border: 1px solid rgba(255,255,255,0.3);
    background: rgba(255,255,255,0.1);
    color: var(--header-text);
    border-radius: 4px;
    font-size: 0.8rem;
    cursor: pointer;
}

.preset-select option {
    background: var(--header-bg);
    color: var(--header-text);
}

.btn {
    padding: 0.35rem 0.75rem;
    border: 1px solid rgba(255,255,255,0.3);
    background: rgba(255,255,255,0.1);
    color: var(--header-text);
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.8rem;
    white-space: nowrap;
}

.btn:hover {
    background: rgba(255,255,255,0.2);
}

.btn-theme {
    font-size: 1rem;
    line-height: 1;
    padding: 0.3rem 0.5rem;
}

.btn-preset.active {
    background: rgba(255,255,255,0.35);
    border-color: rgba(255,255,255,0.6);
}

.btn-logout {
    background: rgba(255,0,0,0.15);
    border-color: rgba(255,0,0,0.3);
}

.btn-logout:hover {
    background: rgba(255,0,0,0.3);
}

/* Overview Card */
.overview-card {
    background: var(--card-bg);
    border-radius: 8px;
    box-shadow: 0 1px 4px var(--card-shadow);
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-around;
    align-items: center;
    gap: 1rem;
}

.overview-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
}

.overview-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    opacity: 0.7;
}

.overview-value {
    font-size: 1.5rem;
    font-weight: 700;
}

.overview-value.compressor-on {
    color: #22c55e;
}

.overview-value.compressor-off {
    opacity: 0.5;
}

/* Charts */
.charts-grid {
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.chart-card {
    background: var(--card-bg);
    border-radius: 8px;
    box-shadow: 0 1px 4px var(--card-shadow);
    padding: 1rem;
}

.chart-card h2 {
    font-size: 0.95rem;
    color: var(--chart-title);
    margin-bottom: 0.5rem;
}

.chart-wrap {
    position: relative;
    width: 100%;
    height: 400px;
}

.chart-loading {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--card-bg);
    z-index: 10;
}

.chart-loading .spinner {
    width: 32px;
    height: 32px;
    border: 3px solid var(--input-border);
    border-top-color: var(--chart-title);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Mobile */
@media (max-width: 600px) {
    .overview-card {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 0.75rem;
        padding: 0.75rem;
    }

    .overview-value {
        font-size: 1.25rem;
    }
}

/* Mobile: collapse preset buttons into dropdown */
@media (max-width: 600px) {
    .presets {
        display: none;
    }

    .preset-select {
        display: block;
    }

    .header {
        padding: 0.5rem;
        gap: 0.5rem;
    }

    .header h1 {
        font-size: 0.95rem;
    }

    .date-controls {
        width: 100%;
    }

    .date-controls label {
        flex: 1;
    }

    .date-controls input {
        width: 100%;
        min-width: 0;
    }
}