:root {
    --byd-red: #686d71;
    --byd-dark: #121212;
    --byd-gray: #f4f7f9;
    --byd-text: #333333;
    --byd-text-light: #6c757d;
    --accent-color: #686d71;
    --card-bg: #ffffff;
    --card-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    --premium-shadow: 0 15px 45px rgba(0, 0, 0, 0.08);
    --transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

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

body {
    background-color: var(--byd-gray);
    color: var(--byd-text);
    font-family: 'Poppins', 'Noto Sans JP', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
    padding-top: 80px;
}

/* Layout */
.simulator-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 20px;
}

.header {
    text-align: center;
    margin-bottom: 70px;
}

.header h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 900;
    letter-spacing: -1px;
    margin-bottom: 20px;
    color: var(--byd-dark);
    text-transform: uppercase;
}

.header h1 span {
    color: var(--byd-red);
}

.header p {
    color: var(--byd-text-light);
    font-size: 1.1rem;
    font-weight: 500;
}

/* Simulator Card */
.simulator-card {
    background: var(--card-bg);
    border-radius: 40px;
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    overflow: hidden;
    box-shadow: var(--premium-shadow);
    border: 1px solid rgba(0,0,0,0.03);
}

@media (max-width: 992px) {
    .simulator-card {
        grid-template-columns: 1fr;
    }
}

/* Input Section */
.input-section {
    padding: 50px;
    background: #ffffff;
}

.input-section h2 {
    margin-bottom: 40px;
    font-size: 0.85rem;
    color: var(--byd-dark);
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 800;
    border-left: 5px solid var(--byd-red);
    padding-left: 20px;
}

.input-group {
    display: flex !important;
    flex-direction: column;
    margin-bottom: 35px;
}

.input-group label {
    display: block;
    margin-bottom: 15px;
    font-weight: 700;
    color: var(--byd-dark);
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.model-tabs {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
}

@media (max-width: 768px) {
    .model-tabs {
        grid-template-columns: repeat(2, 1fr);
    }
}

.model-tab {
    padding: 12px 5px;
    background: #f8f9fa;
    border: 1.5px solid #e9ecef;
    border-radius: 50rem;
    cursor: pointer;
    transition: var(--transition);
    font-size: 11px;
    font-weight: 700;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    white-space: nowrap;
}

.model-tab:hover:not(.active) {
    border-color: #dee2e6;
    background: #e9ecef;
}

.model-tab.active {
    background: var(--byd-red);
    color: white;
    border-color: var(--byd-red);
    box-shadow: 0 8px 20px rgba(104, 109, 113, 0.25);
}

.term-selector {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

@media (max-width: 768px) {
    .term-selector {
        grid-template-columns: repeat(2, 1fr);
    }
}

.term-btn {
    padding: 15px 5px;
    background: #f8f9fa;
    border: 1.5px solid #e9ecef;
    border-radius: 16px;
    cursor: pointer;
    text-align: center;
    transition: var(--transition);
    font-size: 13px;
    font-weight: 700;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 70px;
}

.term-btn.active {
    background: var(--byd-red);
    color: white;
    border-color: var(--byd-red);
}

.term-btn small {
    display: block;
    font-size: 10px;
    margin-top: 4px;
    opacity: 0.8;
}

.input-with-unit {
    position: relative;
    display: flex;
    align-items: center;
}

.custom-input {
    width: 100%;
    background: #f8f9fa;
    border: 1.5px solid #e9ecef;
    border-radius: 12px;
    padding: 15px 45px 15px 15px;
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--byd-red);
    font-family: 'Source Sans 3', sans-serif;
    transition: var(--transition);
}

.custom-input:focus {
    outline: none;
    background: #ffffff;
    border-color: var(--byd-red);
    box-shadow: 0 0 0 4px rgba(104, 109, 113, 0.1);
}

.input-with-unit .unit {
    position: absolute;
    right: 15px;
    font-weight: 700;
    color: var(--byd-text-light);
    pointer-events: none;
}

/* Custom Premium Slider */
.range-slider {
    width: 100%;
    height: 6px;
    background: #e9ecef;
    border-radius: 3px;
    -webkit-appearance: none;
    margin: 15px 0;
    cursor: pointer;
}

.range-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 24px;
    height: 24px;
    background: var(--byd-red);
    border: 4px solid #ffffff;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(104, 109, 113, 0.3);
    transition: var(--transition);
}

.range-slider::-webkit-slider-thumb:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 15px rgba(104, 109, 113, 0.4);
}

.range-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background: var(--byd-red);
    border: 4px solid #ffffff;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(104, 109, 113, 0.3);
}

.slider-values {
    display: flex;
    justify-content: space-between;
    margin-top: 10px;
    font-size: 11px;
    color: var(--byd-text-light);
    font-weight: 600;
}

/* Benefit Box */
.included-features {
    background: #fffcfc !important;
    border: 1.5px dashed rgba(104, 109, 113, 0.15) !important;
    padding: 25px !important;
}

/* Result Section */
.result-section {
    padding: 50px;
    background: linear-gradient(145deg, #fefefe 0%, #f7f8f9 100%);
    border-left: 1px solid #f0f0f0;
    display: flex;
    flex-direction: column;
}

.car-preview h3 {
    font-family: 'Poppins', sans-serif;
    font-weight: 300;
    letter-spacing: 4px;
    font-size: 1.25rem;
}

.car-preview img {
    filter: drop-shadow(0 20px 40px rgba(0,0,0,0.12));
    transition: var(--transition);
}

.monthly-payment {
    font-size: clamp(3.5rem, 9vw, 5.5rem);
    font-weight: 900;
    color: var(--byd-dark);
    line-height: 0.9;
    margin-top: 10px;
    letter-spacing: -2px;
}

.monthly-payment span:last-child {
    font-size: 1.5rem;
    margin-left: 10px;
    font-weight: 700;
    letter-spacing: 0;
}

/* Payment Breakdown Refinement */
.sub-payments {
    margin-top: 40px;
    background: #ffffff;
    border-radius: 20px;
    padding: 24px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.02);
    border: 1px solid #f0f0f0;
}

.sub-payment-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid #f8f9fa;
}

.sub-payment-row:last-child {
    border-bottom: none;
}

.sub-payment-row span:first-child {
    font-size: 13px;
    color: var(--byd-text-light);
    font-weight: 600;
}

.sub-payment-row span:last-child {
    font-size: 15px;
    font-weight: 700;
    color: var(--byd-dark);
    font-family: 'Source Sans 3', sans-serif;
}

.sub-payment-row.total {
    margin-top: 15px;
    padding-top: 20px;
    border-top: 2px solid var(--byd-gray);
    color: var(--byd-red);
}

.sub-payment-row.total span:first-child {
    color: var(--byd-red);
    font-size: 16px;
    font-weight: 800;
}

.sub-payment-row.total span:last-child {
    color: var(--byd-red);
    font-size: 22px;
    font-weight: 900;
}

/* Explanation Section */
.explanation-section {
    padding: 100px 0;
}

.explanation-section .container {
    background: #ffffff;
    border-radius: 40px;
    padding: 80px 60px;
    box-shadow: var(--premium-shadow);
    border: 1px solid rgba(0,0,0,0.02);
}

.feature-card {
    background: #f8f9fa;
    padding: 40px 20px;
    border-radius: 24px;
    text-align: center;
    transition: var(--transition);
    border: 1px solid transparent;
    height: 100%;
}

.feature-card:hover {
    background: #ffffff;
    border-color: var(--byd-red);
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.06);
}

.feature-card i {
    font-size: 2.5rem;
    color: var(--byd-red);
}

.feature-card h6 {
    font-size: 0.95rem;
    font-weight: 800;
    margin-top: 20px;
    color: var(--byd-dark);
}

.step-card {
    background: #fdfdfe;
    padding: 40px 30px;
    border-radius: 28px;
    height: 100%;
    transition: var(--transition);
    text-align: center;
    border: 1.5px solid #f1f3f5;
}

.step-card:hover {
    border-color: rgba(104, 109, 113, 0.2);
    transform: scale(1.02);
}

.step-number {
    background: var(--byd-red);
    color: #ffffff;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
    margin: 0 auto 25px;
    font-size: 1rem;
    box-shadow: 0 5px 15px rgba(104, 109, 113, 0.3);
}

/* CTA */
.btn-primary.btn-lg {
    padding: 20px 45px;
    font-size: 1.1rem;
    letter-spacing: 0.5px;
    transition: var(--transition);
}

.btn-primary.btn-lg:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(104, 109, 113, 0.35);
}

@media (max-width: 768px) {
    .simulator-container { padding: 40px 15px; }
    .explanation-section .container { padding: 50px 20px; }
    .monthly-payment { font-size: 3.5rem; }
}