/* CSS Variables */
:root {
    --color-primary: #3b82f6;
    --color-primary-dark: #2563eb;
    --color-primary-light: #60a5fa;
    --color-secondary: #10b981;
    --color-bg: #0f172a;
    --color-bg-secondary: #1e293b;
    --color-bg-tertiary: #334155;
    --color-text: #f1f5f9;
    --color-text-muted: #94a3b8;
    --color-border: #334155;
    --color-accent: #f59e0b;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.4);
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition: 0.2s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    max-width: 100%;
    display: block;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
}

.logo-img {
    height: 36px;
    width: auto;
}

.footer-logo-img {
    height: 28px;
    width: auto;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-muted);
    transition: color var(--transition);
}

.nav-links a:hover {
    color: var(--color-text);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: var(--transition);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--color-primary);
    color: white;
}

.btn-primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
    background: var(--color-bg-secondary);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-bg-tertiary);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--color-text);
    border: 1px solid var(--color-border);
    padding: 8px 16px;
}

.btn-outline:hover {
    background: var(--color-bg-secondary);
    border-color: var(--color-text-muted);
}

.btn-large {
    padding: 16px 32px;
    font-size: 1rem;
}

/* Icons */
.icon {
    width: 20px;
    height: 20px;
}

.btn-icon {
    width: 18px;
    height: 18px;
}

.nav-icon-link {
    display: flex;
    align-items: center;
}

.nav-icon-link .icon {
    transition: transform var(--transition);
}

.nav-icon-link:hover .icon {
    transform: scale(1.1);
}

.resource-icon svg {
    width: 40px;
    height: 40px;
    color: var(--color-primary-light);
}

/* Badge */
.badge {
    display: inline-block;
    padding: 6px 12px;
    background: rgba(59, 130, 246, 0.15);
    color: var(--color-primary-light);
    font-size: 0.8rem;
    font-weight: 600;
    border-radius: 50px;
    border: 1px solid rgba(59, 130, 246, 0.3);
}

/* Hero Section */
.hero {
    padding: 160px 0 100px;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.1;
    margin: 20px 0 24px;
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-text-muted) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.15rem;
    color: var(--color-text-muted);
    margin-bottom: 32px;
    max-width: 520px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
}

/* Device Mockup */
.hero-visual {
    display: flex;
    justify-content: center;
}

.device-mockup {
    background: var(--color-bg-secondary);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-lg);
}

.oled-screen {
    width: 256px;
    height: 128px;
    background: #000;
    border-radius: 8px;
    padding: 12px 16px;
    font-family: var(--font-mono);
    color: #00ff88;
    display: flex;
    flex-direction: column;
    animation: screenGlow 2s ease-in-out infinite alternate;
}

@keyframes screenGlow {
    from { box-shadow: 0 0 20px rgba(0, 255, 136, 0.2); }
    to { box-shadow: 0 0 30px rgba(0, 255, 136, 0.4); }
}

.screen-header {
    font-size: 0.7rem;
    opacity: 0.7;
    margin-bottom: 4px;
}

.screen-speed {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1;
    animation: speedChange 4s ease-in-out infinite;
}

@keyframes speedChange {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.85; }
}

.screen-unit {
    font-size: 1rem;
    opacity: 0.8;
}

.screen-max {
    font-size: 0.7rem;
    opacity: 0.6;
    margin-top: auto;
}

/* Section Styles */
section {
    padding: 100px 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 16px;
}

.section-desc {
    text-align: center;
    color: var(--color-text-muted);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto 60px;
}

/* Features Section */
.features {
    background: var(--color-bg-secondary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 32px;
    transition: all var(--transition);
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-primary);
    box-shadow: 0 8px 24px rgba(59, 130, 246, 0.15);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.feature-card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* How It Works Section */
.how-it-works {
    background: var(--color-bg);
}

.steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.step {
    text-align: center;
    position: relative;
}

.step:not(:last-child)::after {
    content: '';
    position: absolute;
    top: 32px;
    right: -16px;
    width: 32px;
    height: 2px;
    background: var(--color-border);
}

.step-number {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 auto 20px;
}

.step-content h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.step-content p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* Specs Section */
.specs {
    background: var(--color-bg-secondary);
}

.specs-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.spec-group {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 28px;
}

.spec-group h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--color-border);
}

.spec-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.spec-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.spec-item dt {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

.spec-item dd {
    font-weight: 500;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--color-primary-light);
}

/* Hardware Section */
.hardware {
    background: var(--color-bg);
}

.hardware-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 40px;
    align-items: start;
}

.bom-table {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.bom-table table {
    width: 100%;
    border-collapse: collapse;
}

.bom-table th,
.bom-table td {
    padding: 16px 20px;
    text-align: left;
}

.bom-table th {
    background: var(--color-bg-tertiary);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--color-text-muted);
}

.bom-table td {
    border-top: 1px solid var(--color-border);
    font-size: 0.95rem;
}

.bom-table tr:hover td {
    background: rgba(59, 130, 246, 0.05);
}

.wiring-diagram {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 24px;
}

.wiring-diagram h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.wiring-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.wiring-item {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 0.9rem;
}

.wiring-item .pin {
    font-family: var(--font-mono);
    font-weight: 500;
    color: var(--color-accent);
    min-width: 80px;
}

.wiring-item .arrow {
    color: var(--color-text-muted);
}

.wiring-item .component {
    color: var(--color-text-muted);
}

/* Documentation Section */
.docs {
    background: var(--color-bg-secondary);
}

.docs-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.doc-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 32px;
    text-align: center;
    transition: all var(--transition);
}

.doc-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-primary);
    box-shadow: 0 8px 24px rgba(59, 130, 246, 0.15);
}

.doc-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.doc-card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.doc-card p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* CTA Section */
.cta {
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 100%);
    text-align: center;
    padding: 80px 0;
}

.cta h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.cta p {
    font-size: 1.1rem;
    opacity: 0.9;
    margin-bottom: 32px;
}

.cta .btn-primary {
    background: white;
    color: var(--color-primary-dark);
}

.cta .btn-primary:hover {
    background: var(--color-text);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.cta-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Footer */
.footer {
    background: var(--color-bg);
    border-top: 1px solid var(--color-border);
    padding: 40px 0;
}

.footer-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
}

.footer-copyright {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content h1 {
        font-size: 2.8rem;
    }

    .hero-desc {
        margin: 0 auto 32px;
    }

    .hero-buttons {
        justify-content: center;
    }

    .features-grid,
    .specs-grid,
    .docs-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .steps {
        grid-template-columns: repeat(2, 1fr);
    }

    .step:not(:last-child)::after {
        display: none;
    }

    .hardware-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--color-bg);
        border-bottom: 1px solid var(--color-border);
        padding: 24px;
        flex-direction: column;
        gap: 20px;
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero {
        padding: 120px 0 60px;
        min-height: auto;
    }

    .hero-content h1 {
        font-size: 2.2rem;
    }

    .section-title {
        font-size: 2rem;
    }

    section {
        padding: 60px 0;
    }

    .features-grid,
    .specs-grid,
    .docs-grid,
    .steps {
        grid-template-columns: 1fr;
    }

    .device-mockup {
        transform: scale(0.9);
    }

    .footer-content {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 1.8rem;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .oled-screen {
        width: 200px;
        height: 100px;
    }

    .screen-speed {
        font-size: 2.2rem;
    }
}

/* ===== HOMEPAGE STYLES ===== */

/* Mini 4WD Showcase Animation */
.mini4wd-showcase {
    width: 300px;
    height: 200px;
    position: relative;
    background: var(--color-bg-secondary);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.track-element {
    position: absolute;
    bottom: 40px;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg,
        transparent 0%,
        var(--color-border) 10%,
        var(--color-border) 90%,
        transparent 100%
    );
}

.track-element::before {
    content: '';
    position: absolute;
    top: -20px;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg,
        transparent 0%,
        var(--color-primary) 20%,
        var(--color-primary) 80%,
        transparent 100%
    );
    opacity: 0.5;
}

.car-silhouette {
    position: absolute;
    bottom: 48px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 30px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    border-radius: 8px 20px 4px 4px;
    animation: carBounce 0.5s ease-in-out infinite;
}

.car-silhouette::before {
    content: '';
    position: absolute;
    top: -12px;
    left: 15px;
    width: 40px;
    height: 14px;
    background: var(--color-primary-dark);
    border-radius: 6px 6px 0 0;
}

.car-silhouette::after {
    content: '';
    position: absolute;
    top: 2px;
    right: 8px;
    width: 20px;
    height: 8px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 2px;
}

.wheel {
    position: absolute;
    width: 16px;
    height: 16px;
    background: var(--color-bg-tertiary);
    border: 3px solid var(--color-text-muted);
    border-radius: 50%;
    animation: wheelSpin 0.2s linear infinite;
}

.wheel-fl { bottom: -8px; left: 8px; }
.wheel-fr { bottom: -8px; right: 8px; }
.wheel-rl { bottom: -8px; left: 8px; }
.wheel-rr { bottom: -8px; right: 8px; }

@keyframes carBounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(-2px); }
}

@keyframes wheelSpin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* About Section */
.about {
    background: var(--color-bg);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text p {
    color: var(--color-text-muted);
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 16px;
}

.about-text p:last-child {
    margin-bottom: 0;
}

.about-stats {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.stat {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 24px;
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary-light);
    font-family: var(--font-mono);
}

.stat-label {
    display: block;
    color: var(--color-text-muted);
    font-size: 0.9rem;
    margin-top: 4px;
}

/* Projects Section */
.projects {
    background: var(--color-bg-secondary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

.project-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 32px;
    position: relative;
    transition: all var(--transition);
}

.project-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-primary);
    box-shadow: 0 8px 24px rgba(59, 130, 246, 0.15);
}

.project-card.featured {
    border-color: var(--color-primary);
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.05) 0%, transparent 100%);
}

.project-card.coming-soon {
    opacity: 0.7;
}

.project-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    padding: 4px 10px;
    background: var(--color-primary);
    color: white;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-radius: 4px;
}

.project-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.project-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.project-desc {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 20px;
}

.project-features {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.tag {
    padding: 4px 10px;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

.project-tech {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
}

.project-tech span {
    font-size: 0.85rem;
    color: var(--color-primary-light);
    font-family: var(--font-mono);
}

.project-links {
    display: flex;
    gap: 12px;
}

/* Resources Section */
.resources {
    background: var(--color-bg);
}

.resources-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.resource-card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 32px;
    text-align: center;
    transition: all var(--transition);
}

.resource-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-primary);
    box-shadow: 0 8px 24px rgba(59, 130, 246, 0.15);
}

.resource-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.resource-card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.resource-card p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* Breadcrumb */
.breadcrumb {
    display: inline-block;
    color: var(--color-text-muted);
    font-size: 0.9rem;
    margin-bottom: 16px;
    transition: color var(--transition);
}

.breadcrumb:hover {
    color: var(--color-primary-light);
}

/* Project Hero */
.project-hero .hero-content h1 {
    font-size: 3rem;
}

/* Responsive - Homepage */
@media (max-width: 1024px) {
    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .about-stats {
        flex-direction: row;
        justify-content: center;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }

    .resources-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .about-stats {
        flex-direction: column;
    }

    .resources-grid {
        grid-template-columns: 1fr;
    }

    .mini4wd-showcase {
        width: 250px;
        height: 160px;
    }

    .project-links {
        flex-direction: column;
    }

    .project-links .btn {
        width: 100%;
    }
}