/* ===== CSS Variables ===== */
:root {
    --color-primary: #1d1d1f;
    --color-secondary: #86868b;
    --color-accent: #0071e3;
    --color-accent-hover: #0077ed;
    --color-background: #ffffff;
    --color-surface: #fbfbfd;
    --color-border: #d2d2d7;
    --color-border-light: #e8e8ed;
    
    --font-primary: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Inter', 'Segoe UI', Roboto, sans-serif;
    
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 5rem;
    --spacing-3xl: 8rem;
    
    --max-width: 1200px;
    --header-height: 48px;
    
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    font-size: 17px;
    line-height: 1.47059;
    font-weight: 400;
    letter-spacing: -0.022em;
    color: var(--color-primary);
    background-color: var(--color-background);
}

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

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* ===== Container ===== */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.72);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    z-index: 1000;
    border-bottom: 1px solid var(--color-border-light);
}

.nav {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-size: 21px;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--color-primary);
}

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-links a {
    font-size: 14px;
    color: var(--color-primary);
    opacity: 0.8;
    transition: opacity var(--transition-fast);
}

.nav-links a:hover {
    opacity: 1;
    color: var(--color-primary);
}

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

.mobile-menu-btn span {
    width: 18px;
    height: 1.5px;
    background: var(--color-primary);
    transition: var(--transition-fast);
}

.mobile-menu {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border-light);
    z-index: 999;
}

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

.mobile-nav-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.mobile-nav-links a {
    font-size: 17px;
    color: var(--color-primary);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-size: 17px;
    font-weight: 400;
    border-radius: 980px;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
    text-decoration: none;
}

.btn-primary {
    background: var(--color-accent);
    color: #fff;
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    color: #fff;
}

.btn-secondary {
    background: transparent;
    color: var(--color-accent);
}

.btn-secondary:hover {
    color: var(--color-accent-hover);
}

.btn-full {
    width: 100%;
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: calc(var(--header-height) + var(--spacing-3xl)) var(--spacing-lg) var(--spacing-3xl);
}

.hero-content {
    max-width: 800px;
}

.hero-title {
    font-size: clamp(40px, 8vw, 80px);
    font-weight: 600;
    line-height: 1.05;
    letter-spacing: -0.03em;
    margin-bottom: var(--spacing-md);
}

.hero-title .line {
    display: block;
}

.hero-subtitle {
    font-size: clamp(17px, 2.5vw, 21px);
    color: var(--color-secondary);
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
    line-height: 1.5;
}

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

/* ===== Section Styles ===== */
section {
    padding: var(--spacing-3xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section-label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-accent);
    margin-bottom: var(--spacing-xs);
}

.section-title {
    font-size: clamp(32px, 5vw, 48px);
    font-weight: 600;
    letter-spacing: -0.02em;
}

/* ===== Services Section ===== */
.services {
    background: var(--color-surface);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-lg);
}

.service-card {
    background: var(--color-background);
    padding: var(--spacing-xl);
    border-radius: 18px;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.service-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

.service-icon {
    width: 48px;
    height: 48px;
    margin-bottom: var(--spacing-md);
    color: var(--color-accent);
}

.service-icon svg {
    width: 100%;
    height: 100%;
}

.service-card h3 {
    font-size: 21px;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.01em;
}

.service-card p {
    font-size: 15px;
    color: var(--color-secondary);
    line-height: 1.5;
}

/* ===== About Section ===== */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.about-content .section-label,
.about-content .section-title {
    text-align: left;
}

.about-content .section-title {
    margin-bottom: var(--spacing-lg);
}

.about-text {
    font-size: 17px;
    color: var(--color-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.stats {
    display: flex;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.stat {
    text-align: left;
}

.stat-number {
    display: block;
    font-size: 40px;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--color-primary);
}

.stat-label {
    font-size: 14px;
    color: var(--color-secondary);
}

.about-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.visual-box {
    width: 100%;
    max-width: 400px;
    aspect-ratio: 1;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.visual-element {
    position: absolute;
    border-radius: 24px;
    background: linear-gradient(135deg, var(--color-surface) 0%, var(--color-border-light) 100%);
    border: 1px solid var(--color-border-light);
}

.visual-element:nth-child(1) {
    width: 80%;
    height: 80%;
    animation: float 6s ease-in-out infinite;
}

.visual-element:nth-child(2) {
    width: 60%;
    height: 60%;
    animation: float 6s ease-in-out infinite 1s;
}

.visual-element:nth-child(3) {
    width: 40%;
    height: 40%;
    background: linear-gradient(135deg, var(--color-accent) 0%, #64acff 100%);
    animation: float 6s ease-in-out infinite 2s;
}

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(3deg); }
}

/* ===== Work Section ===== */
.work {
    background: var(--color-surface);
}

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

.work-card {
    background: var(--color-background);
    border-radius: 18px;
    overflow: hidden;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.work-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

.work-card-large {
    grid-column: span 2;
}

.work-image {
    aspect-ratio: 16/9;
    overflow: hidden;
}

.work-card-large .work-image {
    aspect-ratio: 21/9;
}

.work-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #f5f5f7 0%, #e8e8ed 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 21px;
    color: var(--color-secondary);
    font-weight: 500;
}

.work-info {
    padding: var(--spacing-lg);
}

.work-info h3 {
    font-size: 21px;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    letter-spacing: -0.01em;
}

.work-info p {
    font-size: 15px;
    color: var(--color-secondary);
    margin-bottom: var(--spacing-sm);
}

.work-tag {
    display: inline-block;
    font-size: 12px;
    font-weight: 500;
    color: var(--color-accent);
    background: rgba(0, 113, 227, 0.1);
    padding: 4px 12px;
    border-radius: 980px;
}

/* ===== Contact Section ===== */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

.contact-content .section-label,
.contact-content .section-title {
    text-align: left;
}

.contact-content .section-title {
    margin-bottom: var(--spacing-md);
}

.contact-content > p {
    font-size: 17px;
    color: var(--color-secondary);
    margin-bottom: var(--spacing-xl);
    line-height: 1.6;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.contact-label {
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-secondary);
}

.contact-item a {
    font-size: 17px;
    color: var(--color-primary);
}

.contact-item a:hover {
    color: var(--color-accent);
}

.contact-form-container {
    background: var(--color-surface);
    padding: var(--spacing-xl);
    border-radius: 18px;
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    color: var(--color-secondary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    font-size: 17px;
    font-family: inherit;
    border: 1px solid var(--color-border);
    border-radius: 12px;
    background: var(--color-background);
    color: var(--color-primary);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 4px rgba(0, 113, 227, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ===== Footer ===== */
.footer {
    background: var(--color-surface);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
    border-top: 1px solid var(--color-border-light);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-brand .logo {
    margin-bottom: var(--spacing-sm);
}

.footer-brand p {
    font-size: 14px;
    color: var(--color-secondary);
    max-width: 250px;
}

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

.footer-column h4 {
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.footer-column ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-column a {
    font-size: 14px;
    color: var(--color-secondary);
}

.footer-column a:hover {
    color: var(--color-primary);
}

.footer-bottom {
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border-light);
    text-align: center;
}

.footer-bottom p {
    font-size: 12px;
    color: var(--color-secondary);
}

/* ===== Responsive ===== */
@media (max-width: 968px) {
    .about-grid,
    .contact-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
    }
    
    .about-visual {
        order: -1;
    }
    
    .visual-box {
        max-width: 300px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
    
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .work-grid {
        grid-template-columns: 1fr;
    }
    
    .work-card-large {
        grid-column: span 1;
    }
    
    .stats {
        flex-wrap: wrap;
        gap: var(--spacing-lg);
    }
    
    .stat {
        flex: 1 1 80px;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-lg: 1.5rem;
        --spacing-xl: 2rem;
        --spacing-2xl: 3rem;
        --spacing-3xl: 4rem;
    }
    
    .hero-cta {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
    }
}