:root {
    --primary-color: #007bff;
    /* Trustworthy Blue */
    --primary-gradient: linear-gradient(135deg, #0ea5e9 0%, #2563eb 100%);
    --bg-color: transparent;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-sub: #64748b;
    --border-color: #e2e8f0;
    --accent-color: #3b82f6;
    --highlight-bg: #eff6ff;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

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

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-main);
    background-color: var(--bg-color);
    padding: 1rem;
    display: flex;
    justify-content: center;
}

.simulator-container {
    width: 100%;
    max-width: 500px;
}

.card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.header {
    text-align: center;
    margin-bottom: 2rem;
}

.header h2 {
    font-size: 1.5rem;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.header p {
    font-size: 0.875rem;
    color: var(--text-sub);
}

.form-grid {
    display: grid;
    gap: 1rem;
}

.input-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.4rem;
    color: var(--text-main);
}

.select-wrapper,
.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

select,
input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    color: var(--text-main);
    background-color: #f8fafc;
    appearance: none;
    transition: all 0.2s;
}

select:focus,
input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
    background-color: #fff;
}

.chevron,
.unit {
    position: absolute;
    right: 1rem;
    pointer-events: none;
    color: var(--text-sub);
    font-size: 0.8rem;
}

.unit {
    font-size: 0.9rem;
    font-weight: 500;
}

/* Season Toggle */
.season-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin: 1.5rem 0;
    font-size: 0.9rem;
}

.toggle-btn {
    position: relative;
    display: inline-flex;
    align-items: center;
    cursor: pointer;
    background-color: #e2e8f0;
    border-radius: 20px;
    padding: 4px;
    width: 140px;
    height: 36px;
    user-select: none;
}

.toggle-btn input {
    display: none;
}

.slider {
    position: absolute;
    top: 4px;
    left: 4px;
    width: 50%;
    /* Approx half */
    bottom: 4px;
    background-color: white;
    border-radius: 16px;
    transition: transform 0.3s cubic-bezier(0.4, 0.0, 0.2, 1);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    width: 64px;
}

.toggle-btn input:checked+.slider {
    transform: translateX(68px);
    /* Adjust based on width */
    background-color: #f59e0b;
    /* Sunny color */
}

.text-off,
.text-on {
    position: relative;
    z-index: 1;
    flex: 1;
    text-align: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-sub);
    transition: color 0.3s;
}

.toggle-btn input:checked~.text-on {
    color: white;
}

/* Split Inputs Layout */
.split-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

@media (max-width: 400px) {
    .split-inputs {
        grid-template-columns: 1fr;
    }
}

.time-usage-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

@media (max-width: 400px) {
    .time-usage-grid {
        grid-template-columns: 1fr;
    }
}

.toggle-btn input:not(:checked)~.text-off {
    color: var(--text-main);
}

/* Range Slider */
.range-wrapper {
    display: flex;
    align-items: center;
    gap: 1rem;
}

input[type=range] {
    flex: 1;
    cursor: pointer;
    height: 6px;
    background: #e2e8f0;
    border-radius: 4px;
    appearance: none;
    padding: 0;
    border: none;
}

input[type=range]::-webkit-slider-thumb {
    appearance: none;
    height: 20px;
    width: 20px;
    border-radius: 50%;
    background: var(--accent-color);
    cursor: pointer;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    margin-top: -7px;
    /* vertical alignment */
}

input[type=range]::-webkit-slider-runnable-track {
    width: 100%;
    height: 6px;
    background: #e2e8f0;
    border-radius: 4px;
}

.range-value {
    font-weight: 700;
    color: var(--accent-color);
    min-width: 3rem;
    text-align: right;
}

.hint {
    font-size: 0.75rem;
    color: var(--text-sub);
    margin-top: 0.25rem;
}

.hidden {
    display: none !important;
}

.calc-btn {
    width: 100%;
    padding: 1rem;
    background: var(--primary-gradient);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.1s, opacity 0.2s;
    box-shadow: 0 4px 6px -1px rgba(37, 99, 235, 0.3);
}

.calc-btn:hover {
    opacity: 0.95;
    transform: translateY(-1px);
}

.result-area {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 2px dashed var(--border-color);
    animation: slideDown 0.4s ease-out;
}

.result-area.hidden {
    display: none;
}

.price-display {
    text-align: center;
    margin-bottom: 1.5rem;
}

.price-display .label {
    display: block;
    font-size: 0.875rem;
    color: var(--text-sub);
    margin-bottom: 0.5rem;
}

.value-wrapper {
    display: flex;
    justify-content: center;
    align-items: baseline;
    gap: 0.25rem;
    color: var(--text-main);
}

.currency {
    font-size: 1.25rem;
    font-weight: 600;
}

.main-price {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.note {
    font-size: 0.75rem;
    color: var(--text-sub);
    margin-top: 0.5rem;
}

.breakdown {
    background-color: var(--highlight-bg);
    border-radius: 8px;
    padding: 1rem;
}

.breakdown-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-sub);
}

.breakdown-item span:last-child {
    color: var(--text-main);
    font-weight: 600;
}

.breakdown-item.renewable {
    margin-top: 0.75rem;
    padding-top: 0.75rem;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    color: #059669;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 400px) {
    .card {
        padding: 1.5rem;
    }

    .main-price {
        font-size: 2rem;
    }
}