/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-bg: #000000;
    --color-surface: #1c1c1e;
    --color-surface-light: #2c2c2e;
    --color-text: #ffffff;
    --color-text-secondary: #86868b;
    --color-accent: #ff9500;
    --color-accent-hover: #ffb700;
    --color-blue: #0071e3;
    --color-blue-hover: #0077ed;
    --gradient-hero: linear-gradient(180deg, #1a1a2e 0%, #000000 100%);
    --gradient-accent: linear-gradient(135deg, #ff9500 0%, #ff6b00 100%);
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 40px rgba(255, 149, 0, 0.3);
    --transition-smooth: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.5;
    overflow-x: hidden;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    color: var(--color-text);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition-smooth);
    opacity: 0.8;
}

.nav-links a:hover {
    opacity: 1;
}

.cta-nav {
    background: var(--color-accent);
    color: #000 !important;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-weight: 600 !important;
    opacity: 1 !important;
}

.cta-nav:hover {
    background: var(--color-accent-hover);
    transform: scale(1.05);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    background: var(--gradient-hero);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8rem 4rem 4rem;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(ellipse at 30% 20%, rgba(255, 149, 0, 0.15) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 80%, rgba(0, 113, 227, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    max-width: 600px;
    z-index: 1;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 5.5rem);
    font-weight: 800;
    line-height: 1.05;
    margin-bottom: 1.5rem;
}

.hero-title .line {
    display: block;
    opacity: 0;
    transform: translateY(30px);
    animation: fadeUp 0.8s ease forwards;
}

.hero-title .line:nth-child(1) { animation-delay: 0.2s; }
.hero-title .line:nth-child(2) { animation-delay: 0.4s; }
.hero-title .line:nth-child(3) { animation-delay: 0.6s; }

.hero-title .accent {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    margin-bottom: 2.5rem;
    max-width: 480px;
    opacity: 0;
    animation: fadeUp 0.8s ease 0.8s forwards;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    opacity: 0;
    animation: fadeUp 0.8s ease 1s forwards;
}

.btn-primary {
    background: var(--color-accent);
    color: #000;
    padding: 1rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: var(--transition-bounce);
    display: inline-block;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    transform: scale(1.05);
    box-shadow: var(--shadow-glow);
}

.btn-secondary {
    background: transparent;
    color: var(--color-text);
    padding: 1rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    border: 1px solid rgba(255, 255, 255, 0.3);
    transition: var(--transition-smooth);
    display: inline-block;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
}

/* Hero 3D Box */
.hero-visual {
    width: 400px;
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1;
}

.coal-box-hero {
    width: 200px;
    height: 280px;
    perspective: 1000px;
}

.box-3d {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    animation: rotateBox3d 15s linear infinite;
}

.box-3d .face {
    position: absolute;
    background: linear-gradient(135deg, #2a2a3e 0%, #1a1a2e 100%);
    border: 1px solid rgba(255, 149, 0, 0.3);
}

.box-3d .front {
    width: 200px;
    height: 280px;
    transform: translateZ(50px);
    background: linear-gradient(135deg, #ff9500 0%, #ff6b00 100%);
}

.box-3d .back {
    width: 200px;
    height: 280px;
    transform: rotateY(180deg) translateZ(50px);
}

.box-3d .right {
    width: 100px;
    height: 280px;
    transform: rotateY(90deg) translateZ(150px);
}

.box-3d .left {
    width: 100px;
    height: 280px;
    transform: rotateY(-90deg) translateZ(50px);
}

.box-3d .top {
    width: 200px;
    height: 100px;
    transform: rotateX(90deg) translateZ(50px);
    background: linear-gradient(135deg, #ff9500 0%, #ff6b00 100%);
}

.box-3d .bottom {
    width: 200px;
    height: 100px;
    transform: rotateX(-90deg) translateZ(230px);
}

@keyframes rotateBox3d {
    0% { transform: rotateY(0deg) rotateX(5deg); }
    100% { transform: rotateY(360deg) rotateX(5deg); }
}

/* Features Section */
.features {
    padding: 8rem 2rem;
    background: var(--color-bg);
}

.section-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: 4rem;
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-secondary);
    font-size: 1.25rem;
    margin-top: -3rem;
    margin-bottom: 4rem;
}

.features-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--color-surface);
    padding: 2.5rem;
    border-radius: 24px;
    text-align: center;
    transition: var(--transition-smooth);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: rgba(255, 149, 0, 0.3);
    box-shadow: var(--shadow-glow);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.feature-card p {
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* Quality Section */
.quality {
    padding: 8rem 2rem;
    background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-surface) 100%);
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1400px;
    margin: 0 auto;
    gap: 4rem;
}

.quality-content {
    flex: 1;
}

.quality-stats {
    display: flex;
    gap: 3rem;
    margin-top: 3rem;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 3.5rem;
    font-weight: 800;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

.quality-visual {
    flex: 1;
    display: flex;
    justify-content: center;
}

.coal-showcase {
    display: flex;
    gap: 1rem;
    align-items: flex-end;
}

.coal-piece {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #3d3d3d 0%, #1a1a1a 100%);
    border-radius: 12px;
    position: relative;
    animation: float 3s ease-in-out infinite;
}

.coal-piece::before {
    content: '';
    position: absolute;
    top: 10%;
    left: 10%;
    right: 10%;
    bottom: 10%;
    background: radial-gradient(ellipse at 30% 30%, rgba(255, 100, 0, 0.6) 0%, transparent 60%);
    border-radius: 8px;
}

.coal-piece:nth-child(1) { animation-delay: 0s; height: 60px; }
.coal-piece:nth-child(2) { animation-delay: 0.5s; height: 80px; }
.coal-piece:nth-child(3) { animation-delay: 1s; height: 70px; }

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

/* Builder Section */
.builder {
    padding: 8rem 2rem;
    background: var(--color-bg);
}

.builder-container {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

/* 3D Box Preview */
.preview-section {
    position: sticky;
    top: 100px;
}

.box-container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.scene {
    width: 300px;
    height: 400px;
    perspective: 1200px;
    margin-bottom: 2rem;
}

.box {
    width: 180px;
    height: 260px;
    position: relative;
    transform-style: preserve-3d;
    transform: rotateY(-30deg) rotateX(10deg);
    transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    margin: 70px auto;
}

.face {
    position: absolute;
    background: var(--color-surface);
    border: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    backface-visibility: hidden;
}

.face img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.placeholder-text {
    color: var(--color-text-secondary);
    font-size: 0.8rem;
    text-align: center;
    padding: 1rem;
}

.face-front {
    width: 180px;
    height: 260px;
    transform: translateZ(45px);
}

.face-back {
    width: 180px;
    height: 260px;
    transform: rotateY(180deg) translateZ(45px);
}

.face-right {
    width: 90px;
    height: 260px;
    transform: rotateY(90deg) translateZ(135px);
}

.face-left {
    width: 90px;
    height: 260px;
    transform: rotateY(-90deg) translateZ(45px);
}

.face-top {
    width: 180px;
    height: 90px;
    transform: rotateX(90deg) translateZ(45px);
}

.face-bottom {
    width: 180px;
    height: 90px;
    transform: rotateX(-90deg) translateZ(215px);
}

/* Box Shape Variants */

/* Small Box - 25mm 12pcs / 26mm 8pcs - Long rectangular prism, low height */
.box.box-small {
    width: 200px;
    height: 60px;
    margin: 170px auto;
}

.box.box-small .face-front {
    width: 200px;
    height: 60px;
    transform: translateZ(25px);
}

.box.box-small .face-back {
    width: 200px;
    height: 60px;
    transform: rotateY(180deg) translateZ(25px);
}

.box.box-small .face-right {
    width: 50px;
    height: 60px;
    transform: rotateY(90deg) translateZ(175px);
}

.box.box-small .face-left {
    width: 50px;
    height: 60px;
    transform: rotateY(-90deg) translateZ(25px);
}

.box.box-small .face-top {
    width: 200px;
    height: 50px;
    transform: rotateX(90deg) translateZ(25px);
}

.box.box-small .face-bottom {
    width: 200px;
    height: 50px;
    transform: rotateX(-90deg) translateZ(35px);
}

/* Large Box 25mm - 72pcs - Square base prism */
.box.box-large-25 {
    width: 160px;
    height: 160px;
    margin: 120px auto;
}

.box.box-large-25 .face-front {
    width: 160px;
    height: 160px;
    transform: translateZ(80px);
}

.box.box-large-25 .face-back {
    width: 160px;
    height: 160px;
    transform: rotateY(180deg) translateZ(80px);
}

.box.box-large-25 .face-right {
    width: 160px;
    height: 160px;
    transform: rotateY(90deg) translateZ(80px);
}

.box.box-large-25 .face-left {
    width: 160px;
    height: 160px;
    transform: rotateY(-90deg) translateZ(80px);
}

.box.box-large-25 .face-top {
    width: 160px;
    height: 160px;
    transform: rotateX(90deg) translateZ(80px);
}

.box.box-large-25 .face-bottom {
    width: 160px;
    height: 160px;
    transform: rotateX(-90deg) translateZ(80px);
}

/* Large Box 26mm - 64pcs - Perfect CUBE */
.box.box-large-26 {
    width: 150px;
    height: 150px;
    margin: 125px auto;
}

.box.box-large-26 .face-front {
    width: 150px;
    height: 150px;
    transform: translateZ(75px);
}

.box.box-large-26 .face-back {
    width: 150px;
    height: 150px;
    transform: rotateY(180deg) translateZ(75px);
}

.box.box-large-26 .face-right {
    width: 150px;
    height: 150px;
    transform: rotateY(90deg) translateZ(75px);
}

.box.box-large-26 .face-left {
    width: 150px;
    height: 150px;
    transform: rotateY(-90deg) translateZ(75px);
}

.box.box-large-26 .face-top {
    width: 150px;
    height: 150px;
    transform: rotateX(90deg) translateZ(75px);
}

.box.box-large-26 .face-bottom {
    width: 150px;
    height: 150px;
    transform: rotateX(-90deg) translateZ(75px);
}

.rotation-controls {
    display: flex;
    gap: 0.5rem;
}

.rotate-btn {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 1px solid rgba(255, 255, 255, 0.2);
    background: var(--color-surface);
    color: var(--color-text);
    font-size: 1.2rem;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.rotate-btn:hover {
    background: var(--color-surface-light);
    border-color: var(--color-accent);
}

/* Config Panel */
.config-section {
    background: var(--color-surface);
    border-radius: 24px;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.config-step {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.config-step:last-of-type {
    border-bottom: none;
}

.config-step h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--color-text);
}

.option-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.option-card {
    display: flex;
    align-items: center;
    padding: 1rem 1.25rem;
    background: var(--color-surface-light);
    border-radius: 12px;
    cursor: pointer;
    transition: var(--transition-smooth);
    border: 2px solid transparent;
}

.option-card:hover {
    background: rgba(255, 149, 0, 0.1);
}

.option-card input[type="radio"] {
    display: none;
}

.option-card input[type="radio"]:checked + .option-content,
.option-card:has(input[type="radio"]:checked) {
    border-color: var(--color-accent);
    background: rgba(255, 149, 0, 0.15);
}

.option-card:has(input[type="radio"]:checked) {
    border: 2px solid var(--color-accent);
}

.option-content {
    display: flex;
    flex-direction: column;
    flex: 1;
}

.option-title {
    font-weight: 600;
    font-size: 1rem;
}

.option-desc {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

.hidden {
    display: none !important;
}

/* Design Upload */
.design-options {
    margin-bottom: 1rem;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--color-accent);
}

.upload-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.upload-zone {
    aspect-ratio: 1;
    background: var(--color-surface-light);
    border: 2px dashed rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.upload-zone:hover {
    border-color: var(--color-accent);
    background: rgba(255, 149, 0, 0.05);
}

.upload-zone.has-image {
    border-style: solid;
    border-color: var(--color-accent);
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
    text-align: center;
}

.upload-icon {
    font-size: 2rem;
}

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

.upload-hint {
    font-size: 0.75rem;
    color: var(--color-text-secondary);
}

.upload-preview {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-size: cover;
    background-position: center;
}

.upload-preview.hidden {
    display: none;
}

/* Quantity Selector */
.quantity-selector {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.qty-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid rgba(255, 255, 255, 0.2);
    background: var(--color-surface-light);
    color: var(--color-text);
    font-size: 1.2rem;
    cursor: pointer;
    transition: var(--transition-smooth);
    display: flex;
    align-items: center;
    justify-content: center;
}

.qty-btn:hover {
    background: var(--color-accent);
    color: #000;
    border-color: var(--color-accent);
}

#quantity {
    width: 80px;
    height: 44px;
    text-align: center;
    background: var(--color-surface-light);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    color: var(--color-text);
    font-size: 1.1rem;
    font-weight: 600;
}

.qty-unit {
    color: var(--color-text-secondary);
}

.min-order {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    margin-top: 0.5rem;
}

/* Price Section */
.price-section {
    background: var(--color-surface-light);
    border-radius: 16px;
    padding: 1.5rem;
    margin: 2rem 0;
}

.price-breakdown {
    margin-bottom: 1rem;
}

.price-row {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
    color: var(--color-text-secondary);
    font-size: 0.95rem;
}

.price-row.discount {
    color: #34c759;
}

.total-price {
    display: flex;
    justify-content: space-between;
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 1.5rem;
    font-weight: 700;
}

.total-price span:last-child {
    color: var(--color-accent);
}

/* Submit Button */
.submit-btn {
    width: 100%;
    padding: 1.25rem;
    background: var(--gradient-accent);
    color: #000;
    border: none;
    border-radius: 14px;
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition-bounce);
}

.submit-btn:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-glow);
}

/* Contact Section */
.contact {
    padding: 8rem 2rem;
    background: var(--color-surface);
}

.contact-content {
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

.contact-subtitle {
    color: var(--color-text-secondary);
    font-size: 1.25rem;
    margin-top: -3rem;
    margin-bottom: 4rem;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.contact-card {
    background: var(--color-surface-light);
    padding: 2.5rem;
    border-radius: 20px;
    transition: var(--transition-smooth);
}

.contact-card:hover {
    transform: translateY(-5px);
    border: 1px solid rgba(255, 149, 0, 0.3);
}

.contact-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    display: block;
}

.contact-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.contact-card a {
    color: var(--color-accent);
    text-decoration: none;
    font-weight: 500;
}

.contact-card a:hover {
    text-decoration: underline;
}

.contact-card p {
    color: var(--color-text-secondary);
}

/* Footer */
.footer {
    background: var(--color-bg);
    padding: 4rem 2rem 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 3rem;
}

.footer-brand .logo {
    font-size: 1.75rem;
    display: block;
    margin-bottom: 0.5rem;
}

.footer-brand p {
    color: var(--color-text-secondary);
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--color-text);
    text-decoration: none;
    opacity: 0.7;
    transition: var(--transition-smooth);
}

.footer-links a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-bottom p {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.9);
    backdrop-filter: blur(10px);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    overflow-y: auto;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--color-surface);
    border-radius: 24px;
    padding: 2.5rem;
    max-width: 500px;
    width: 100%;
    position: relative;
    animation: modalSlide 0.4s ease;
    max-height: 90vh;
    overflow-y: auto;
}

@keyframes modalSlide {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    color: var(--color-text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-smooth);
}

.modal-close:hover {
    background: var(--color-surface-light);
    color: var(--color-text);
}

.modal-content h2 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
}

.modal-content > p {
    color: var(--color-text-secondary);
    margin-bottom: 1.5rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--color-surface-light);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    color: var(--color-text);
    font-size: 1rem;
    transition: var(--transition-smooth);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-accent);
}

.order-summary {
    background: var(--color-surface-light);
    border-radius: 12px;
    padding: 1.25rem;
    margin: 1.5rem 0;
}

.order-summary h3 {
    font-size: 1rem;
    margin-bottom: 1rem;
}

.summary-row {
    display: flex;
    justify-content: space-between;
    padding: 0.35rem 0;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

.summary-row.total {
    margin-top: 0.75rem;
    padding-top: 0.75rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-weight: 700;
    color: var(--color-text);
    font-size: 1.1rem;
}

/* Animations */
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 1024px) {
    .builder-container {
        grid-template-columns: 1fr;
    }
    
    .preview-section {
        position: relative;
        top: 0;
        order: -1;
    }
    
    .scene {
        width: 250px;
        height: 320px;
    }
    
    .quality {
        flex-direction: column;
        text-align: center;
    }
    
    .quality-stats {
        justify-content: center;
    }
}

@media (max-width: 768px) {
    .hero {
        flex-direction: column;
        padding: 7rem 1.5rem 3rem;
        text-align: center;
    }
    
    .hero-content {
        max-width: 100%;
    }
    
    .hero-buttons {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .hero-visual {
        width: 250px;
        height: 250px;
        margin-top: 2rem;
    }
    
    .coal-box-hero {
        width: 120px;
        height: 170px;
    }
    
    .box-3d .front,
    .box-3d .back {
        width: 120px;
        height: 170px;
    }
    
    .box-3d .right,
    .box-3d .left {
        width: 60px;
        height: 170px;
    }
    
    .box-3d .top,
    .box-3d .bottom {
        width: 120px;
        height: 60px;
    }
    
    .nav-links {
        display: none;
    }
    
    .features,
    .quality,
    .builder,
    .contact {
        padding: 4rem 1rem;
    }
    
    .upload-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .quality-stats {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 2rem;
        text-align: center;
    }
    
    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
    background: var(--color-surface-light);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-accent);
}