:root {
    --primary: #4361ee;
    --secondary: #3f37c9;
    --accent: #4895ef;
    --dark: #1b263b;
    --light: #f8f9fa;
    --success: #4cc9f0;
    --danger: #f72585;
    --warning: #f8961e;
    --whatsapp: #25D366;
    --messenger: #006AFF;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}

body {
    background-color: #f8fafc;
    color: #1e293b;
    line-height: 1.6;
    padding-top: 80px;
}

/* Header Styles */
header {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
    display: flex;
    align-items: center;
}

.logo i {
    margin-right: 0.5rem;
    font-size: 1.5rem;
}

nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin-left: 2rem;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
}

nav ul li a:hover {
    color: var(--accent);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Page Header */
.page-header {
    text-align: center;
    padding: 2rem 1rem;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
}

.page-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIxMDAlIiBoZWlnaHQ9IjEwMCUiPjxkZWZzPjxwYXR0ZXJuIGlkPSJwYXR0ZXJuIiB3aWR0aD0iNDAiIGhlaWdodD0iNDAiIHBhdHRlcm5Vbml0cz0idXNlclNwYWNlT25Vc2UiIHBhdHRlcm5UcmFuc2Zvcm09InJvdGF0ZSg0NSkiPjxyZWN0IHdpZHRoPSIyMCIgaGVpZ2h0PSIyMCIgZmlsbD0icmdiYSgyNTUsMjU1LDI1NSwwLjA1KSIvPjwvcGF0dGVybj48L2RlZnM+PHJlY3QgZmlsbD0idXJsKCNwYXR0ZXJuKSIgd2lkdGg9IjEwMCUiIGhlaWdodD0iMTAwJSIvPjwvc3ZnPg==');
    opacity: 0.4;
}

.page-header-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
}

.page-title {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.page-subtitle {
    font-size: 1rem;
    opacity: 0.9;
    font-weight: 300;
}

/* Calculator Container */
.calculator-container {
    max-width: 1000px;
    margin: 0 auto 2rem;
    padding: 0 2rem;
}

.calculator-card {
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    padding: 2rem;
    margin-bottom: 2rem;
}

.config-section {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
}

.config-section:last-child {
    border-bottom: none;
}

.section-title {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--dark);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.section-title i {
    color: var(--primary);
}

.option-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1rem;
    margin-bottom: 1rem;
}

/* Region server dalam 4 baris */
.region-group {
    grid-template-columns: repeat(4, 1fr);
}

.option {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    position: relative;
}

.option:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
}

.option.selected {
    border-color: var(--primary);
    background: #e3f2fd;
}

.option.disabled {
    opacity: 0.5;
    cursor: not-allowed;
    background: #f8f9fa;
}

.option.disabled:hover {
    transform: none;
    border-color: #e9ecef;
}

.windows-restriction-badge {
    position: absolute;
    top: -8px;
    right: -8px;
    background: var(--warning);
    color: white;
    font-size: 0.7rem;
    padding: 2px 6px;
    border-radius: 10px;
    font-weight: 600;
}

.option-icon {
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.option-title {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.option-desc {
    font-size: 0.8rem;
}

.config-preset {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-top: 1rem;
}

.preset-option {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 10px;
    padding: 1.25rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.preset-option:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
}

.preset-option.selected {
    border-color: var(--primary);
    background: #f8f9fa;
}

.preset-option.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.preset-option.disabled:hover {
    transform: none;
    border-color: #e9ecef;
}

.preset-icon {
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.preset-title {
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 1rem;
}

.preset-specs {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.spec-item {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: 1rem;
}

.preset-price {
    font-weight: 700;
    color: var(--primary);
    font-size: 1rem;
}

/* Windows Restriction Info */
.windows-restriction-info {
    margin-top: 1rem;
    padding: 0.75rem;
    background: #fff3cd;
    border: 1px solid #ffeaa7;
    border-radius: 8px;
    border-left: 4px solid #f39c12;
}

.windows-restriction-info p {
    margin: 0;
    font-size: 0.85rem;
    color: #856404;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.windows-restriction-info i {
    color: #f39c12;
    font-size: 0.9rem;
}

/* Windows Note Styles */
.windows-note {
    margin-top: 1rem;
    padding: 0.75rem;
    background: #fff3cd;
    border: 1px solid #ffeaa7;
    border-radius: 8px;
    border-left: 4px solid #fdcb6e;
}

.windows-note p {
    margin: 0;
    font-size: 0.85rem;
    color: #856404;
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
}

.windows-note i {
    color: #f39c12;
    margin-top: 0.1rem;
    flex-shrink: 0;
}

/* Price Display */
.price-display {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    border-radius: 15px;
    padding: 2rem;
    text-align: center;
    margin: 2rem 0;
}

.warranty-period {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.warranty-btn {
    padding: 0.5rem 1rem;
    background: rgba(255,255,255,0.2);
    border: none;
    border-radius: 20px;
    color: white;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.warranty-btn.active {
    background: rgba(255,255,255,0.4);
    font-weight: 600;
}

.total-price {
    font-size: 2.5rem;
    font-weight: 700;
    margin: 1rem 0;
}

.config-summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1rem;
    margin-top: 1.5rem;
}

.config-item {
    background: rgba(255,255,255,0.1);
    padding: 0.75rem;
    border-radius: 8px;
}

.config-value {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.config-label {
    font-size: 0.8rem;
    opacity: 0.9;
}

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    color: white;
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    width: 100%;
    margin-top: 1rem;
}

.btn-whatsapp {
    background: var(--whatsapp);
}

.btn-whatsapp:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 211, 102, 0.4);
}

.btn-messenger {
    background: var(--messenger);
}

.btn-messenger:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 106, 255, 0.4);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
    box-shadow: none !important;
}

.button-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 1rem;
}

.warranty-info {
    background: #f0f9ff;
    border-left: 4px solid var(--primary);
    padding: 1rem;
    margin-top: 1.5rem;
    border-radius: 0 8px 8px 0;
    font-size: 0.9rem;
}

.warranty-info h3 {
    color: var(--dark);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.warranty-info p {
    margin: 0.25rem 0;
    color: var(--dark);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.warranty-info i {
    color: var(--primary);
    width: 16px;
}

/* OS Version Selection Styles */
.os-version-selection {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid #e2e8f0;
}

.os-version-group {
    display: none;
    animation: fadeIn 0.3s ease;
}

.os-version-group.active {
    display: block;
}

.os-version-group.disabled {
    opacity: 0.5;
    pointer-events: none;
}

.os-version-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--dark);
}

.os-version-select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    color: var(--dark);
    background: white;
    transition: all 0.3s ease;
    cursor: pointer;
}

.os-version-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}

.os-version-select:disabled {
    background: #f8f9fa;
    cursor: not-allowed;
    opacity: 0.6;
}

.os-version-select optgroup {
    font-weight: 600;
    color: var(--primary);
}

.os-version-select option {
    padding: 0.5rem;
}

/* Quantity Control Styles */
.quantity-control {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.quantity-input-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.quantity-btn {
    background: var(--primary);
    color: white;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.quantity-btn:hover {
    background: var(--secondary);
    transform: scale(1.05);
}

.quantity-input {
    width: 80px;
    height: 40px;
    text-align: center;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    color: var(--dark);
    background: white;
    transition: all 0.3s ease;
}

.quantity-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}

.quantity-info {
    text-align: center;
    color: #64748b;
    font-size: 0.9rem;
}

.quantity-info p {
    margin: 0;
}

/* Usage Purpose Styles */
.usage-purpose {
    margin-top: 1rem;
}

.usage-purpose label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--dark);
}

.usage-purpose label.required {
    font-weight: 600;
}

.required-star {
    color: var(--danger);
    margin-left: 2px;
}

.usage-purpose-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    color: var(--dark);
    background: white;
    transition: all 0.3s ease;
    resize: vertical;
    min-height: 80px;
    font-family: 'Poppins', sans-serif;
}

.usage-purpose-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}

.usage-purpose-input::placeholder {
    color: #94a3b8;
}

.usage-purpose-input:invalid {
    border-color: var(--danger);
}

.usage-purpose-input:valid {
    border-color: var(--success);
}

.input-info {
    margin-top: 0.5rem;
    padding: 0.5rem;
    background: #f0f9ff;
    border-radius: 6px;
    border-left: 3px solid var(--primary);
}

.input-info p {
    margin: 0;
    font-size: 0.8rem;
    color: var(--dark);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.input-info i {
    color: var(--primary);
    font-size: 0.9rem;
}

/* Error State */
.usage-purpose-input.error {
    border-color: var(--danger);
    background: #fef2f2;
}

.error-message {
    color: var(--danger);
    font-size: 0.8rem;
    margin-top: 0.25rem;
    display: none;
}

.error-message.show {
    display: block;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Footer */
.copyright {
    text-align: center;
    padding: 1.5rem;
    background-color: var(--dark);
    color: white;
    width: 100%;
}

/* Responsive Styles */
@media (max-width: 768px) {
    body {
        padding-top: 70px;
    }
    
    .nav-container {
        padding: 0 1rem;
    }
    
    nav ul {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: linear-gradient(135deg, var(--primary), var(--secondary));
        flex-direction: column;
        padding: 1rem 0;
        box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
    }
    
    nav ul.show {
        display: flex;
    }
    
    nav ul li {
        margin: 0;
        text-align: center;
    }
    
    nav ul li a {
        display: block;
        padding: 1rem;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .calculator-container {
        padding: 0 1rem;
    }
    
    .calculator-card {
        padding: 1.5rem;
    }
    
    .option-group {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .region-group {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .config-preset {
        grid-template-columns: 1fr;
    }
    
    .warranty-period {
        flex-direction: column;
        align-items: center;
    }
    
    .warranty-btn {
        width: 100%;
        max-width: 200px;
    }
    
    .total-price {
        font-size: 2rem;
    }
    
    .config-summary {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .os-version-select {
        padding: 0.6rem 0.8rem;
        font-size: 0.9rem;
    }
    
    .quantity-input-group {
        gap: 0.25rem;
    }
    
    .quantity-btn {
        width: 36px;
        height: 36px;
        font-size: 0.8rem;
    }
    
    .quantity-input {
        width: 70px;
        height: 36px;
        font-size: 0.9rem;
    }
    
    .usage-purpose-input {
        padding: 0.6rem 0.8rem;
        font-size: 0.9rem;
        min-height: 70px;
    }
    
    .input-info p {
        font-size: 0.75rem;
    }
    
    .windows-note p {
        font-size: 0.8rem;
    }
    
    .windows-restriction-info p {
        font-size: 0.8rem;
    }
    
    .button-group {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
    
    .btn {
        padding: 0.875rem 1.5rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .logo {
        font-size: 1.5rem;
    }
    
    .page-title {
        font-size: 1.8rem;
    }
    
    .option-group {
        grid-template-columns: 1fr;
    }
    
    .region-group {
        grid-template-columns: 1fr;
    }
    
    .config-summary {
        grid-template-columns: 1fr;
    }
    
    .total-price {
        font-size: 1.8rem;
    }
    
    .warranty-btn {
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }
    
    .config-item {
        padding: 0.5rem;
    }
    
    .config-value {
        font-size: 0.9rem;
    }
    
    .config-label {
        font-size: 0.7rem;
    }
    
    .btn {
        padding: 0.75rem 1.25rem;
        font-size: 0.85rem;
    }
    
    .windows-restriction-badge {
        font-size: 0.6rem;
        padding: 1px 4px;
    }
}