/* Reset & Variables */
:root {
    --primary-color: #3b82f6;
    --primary-dark: #2563eb;
    --secondary-color: #64748b;
    --bg-color: #0f172a;
    --bg-card: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --gradient-main: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);

    --font-main: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;

    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;

    --container-width: 1200px;
    --header-height: 80px;

    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;

    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

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

/* Utilities */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

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

.section {
    padding: var(--spacing-xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.section-desc {
    color: var(--text-muted);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

/* Buttons */
.btn-primary {
    display: inline-block;
    padding: 1rem 2rem;
    background: var(--primary-color);
    color: white;
    border-radius: var(--radius-sm);
    font-weight: 600;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-secondary {
    display: inline-block;
    padding: 1rem 2rem;
    background: var(--bg-card);
    color: var(--text-main);
    border-radius: var(--radius-sm);
    font-weight: 600;
    border: 1px solid var(--border-color);
}

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

.btn-outline {
    display: inline-block;
    padding: 1rem 2rem;
    background: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
    border-radius: var(--radius-sm);
    font-weight: 600;
    text-align: center;
}

.btn-outline:hover {
    background: rgba(59, 130, 246, 0.1);
}

.full-width {
    width: 100%;
    text-align: center;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.nav-list a {
    font-weight: 500;
    color: var(--text-muted);
}

.nav-list a:hover,
.nav-list a.active {
    color: var(--text-main);
}

.nav-list .btn-primary {
    padding: 0.5rem 1.5rem;
    color: white;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-main);
    margin: 5px 0;
}

/* Hero */
.hero {
    padding-top: calc(var(--header-height) + var(--spacing-xl));
    padding-bottom: var(--spacing-xl);
    text-align: center;
}

.hero-title {
    font-size: 4rem;
    line-height: 1.1;
    font-weight: 800;
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: var(--spacing-lg);
}

.hero-buttons {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
}

/* Services */
.service-card {
    background: var(--bg-card);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.service-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-5px);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.service-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.service-card p {
    color: var(--text-muted);
    margin-bottom: var(--spacing-md);
}

.check-list li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-muted);
}

.check-list li::before {
    content: "✓";
    color: var(--primary-color);
    font-weight: bold;
}

/* Portfolio */
.portfolio-grid {
    gap: 2rem;
}

.portfolio-item {
    group: relative;
    cursor: pointer;
}

.portfolio-thumb {
    width: 100%;
    aspect-ratio: 16/9;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
    overflow: hidden;
    position: relative;
}

.portfolio-thumb::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, transparent 0%, rgba(0, 0, 0, 0.5) 100%);
    opacity: 0;
    transition: var(--transition);
}

.portfolio-item:hover .portfolio-thumb::after {
    opacity: 1;
}

.portfolio-info h4 {
    font-size: 1.25rem;
    margin-bottom: 0.25rem;
}

.portfolio-info span {
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Process */
.process-steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.step {
    position: relative;
    padding: 2rem;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.step-number {
    font-size: 3rem;
    font-weight: 800;
    color: rgba(255, 255, 255, 0.05);
    position: absolute;
    top: 1rem;
    right: 1rem;
}

.step h4 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.step p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Testimonials */
.testimonial-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.testimonial-text {
    font-size: 1.1rem;
    font-style: italic;
    margin-bottom: 1.5rem;
    color: var(--text-main);
}

.testimonial-author {
    color: var(--text-muted);
    font-weight: 600;
}

/* Pricing */
.pricing-card {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    position: relative;
    display: flex;
    flex-direction: column;
}

.pricing-card.popular {
    border-color: var(--primary-color);
    background: linear-gradient(to bottom, var(--bg-card), rgba(59, 130, 246, 0.05));
}

.badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 1rem;
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 700;
}

.pricing-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.price-desc {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.pricing-card .check-list {
    margin-bottom: 2rem;
    flex-grow: 1;
}

/* FAQ */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border-bottom: 1px solid var(--border-color);
}

.faq-question {
    padding: 1.5rem 0;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    font-size: 1.1rem;
}

.toggle-icon {
    font-size: 1.5rem;
    color: var(--primary-color);
    transition: var(--transition);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: var(--transition);
    color: var(--text-muted);
}

.faq-item.active .faq-answer {
    max-height: 200px;
    padding-bottom: 1.5rem;
}

.faq-item.active .toggle-icon {
    transform: rotate(45deg);
}

/* Contact */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 4rem;
    background: var(--bg-card);
    padding: 4rem;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
}

.contact-info h2 {
    margin-bottom: 1rem;
}

.contact-info p {
    color: var(--text-muted);
    margin-bottom: 3rem;
}

.contact-item {
    margin-bottom: 1.5rem;
}

.contact-item strong {
    display: block;
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
}

.contact-item a {
    font-size: 1.25rem;
    font-weight: 600;
}

.form-group {
    margin-bottom: 1.5rem;
}

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

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="tel"],
.form-group textarea {
    width: 100%;
    padding: 1rem;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-main);
    font-family: inherit;
}

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

.file-upload small {
    display: block;
    margin-top: 0.5rem;
    color: var(--text-muted);
}

.checkbox {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.checkbox input {
    width: auto;
}

.link {
    color: var(--primary-color);
    text-decoration: underline;
}

/* Footer */
.footer {
    padding: 4rem 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-muted);
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 1rem;
}

.footer-links {
    margin: 1.5rem 0;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-list {
        display: none;
        position: absolute;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: var(--bg-card);
        flex-direction: column;
        padding: 2rem;
        border-bottom: 1px solid var(--border-color);
    }

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

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

    .hero-title {
        font-size: 2.5rem;
    }

    .grid-2,
    .grid-3,
    .process-steps {
        grid-template-columns: 1fr;
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
        padding: 2rem;
    }
}