/* ===================================
   B2B Partnership Website
   깔끔하고 전문적인 파트너십 중심 디자인
   =================================== */

:root {
    /* Brand Colors - 신뢰와 전문성 */
    --color-primary: #2563EB;
    --color-primary-dark: #1D4ED8;
    --color-secondary: #7C3AED;
    --color-accent: #0EA5E9;
    
    /* Neutral Colors */
    --color-bg: #FFFFFF;
    --color-bg-light: #F8FAFC;
    --color-bg-gray: #F1F5F9;
    --color-text: #0F172A;
    --color-text-light: #64748B;
    --color-border: #E2E8F0;
    
    /* Status Colors */
    --color-success: #10B981;
    --color-warning: #F59E0B;
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-korean: 'Noto Sans KR', sans-serif;
}

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

body {
    font-family: var(--font-korean), var(--font-primary);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 32px;
}

/* ===================================
   Header
   =================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    z-index: 100;
    transition: all 0.3s ease;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 88px;
}

.logo img {
    display: block;
    transition: all 0.3s ease;
}

.logo img:hover {
    transform: scale(1.05);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 48px;
}

.nav-menu a {
    color: var(--color-text);
    text-decoration: none;
    font-weight: 500;
    font-size: 15px;
    transition: color 0.3s ease;
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transition: width 0.3s ease;
}

.nav-menu a:hover {
    color: var(--color-primary);
}

.nav-menu a:hover::after {
    width: 100%;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.nav-phone {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--color-text);
    text-decoration: none;
    font-weight: 600;
    font-size: 15px;
    transition: color 0.3s ease;
}

.nav-phone svg {
    stroke: var(--color-primary);
}

.nav-phone:hover {
    color: var(--color-primary);
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: white;
    border: none;
    padding: 12px 28px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.2);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
}

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

.menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: all 0.3s ease;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    padding: 180px 0 120px;
    background: linear-gradient(180deg, #F8FAFC 0%, #FFFFFF 100%);
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: white;
    border: 1px solid var(--color-border);
    padding: 10px 24px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 14px;
    color: var(--color-text);
    margin-bottom: 32px;
    box-shadow: var(--shadow-sm);
}

.badge-icon {
    font-size: 18px;
}

.hero-title {
    font-size: 64px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.title-line {
    color: var(--color-text-light);
    font-size: 48px;
    font-weight: 700;
}

.title-highlight {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 20px;
    color: var(--color-text-light);
    line-height: 1.7;
    margin-bottom: 64px;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

.stat-card {
    background: white;
    border: 1px solid var(--color-border);
    border-radius: 16px;
    padding: 32px 24px;
    text-align: center;
    transition: all 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.stat-icon {
    font-size: 32px;
    margin-bottom: 12px;
}

.stat-value {
    font-size: 36px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 14px;
    color: var(--color-text-light);
    font-weight: 500;
}

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

.btn-large {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: white;
    border: none;
    padding: 18px 40px;
    border-radius: 10px;
    font-weight: 700;
    font-size: 17px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
}

.btn-large:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(37, 99, 235, 0.4);
}

.btn-outline {
    background: white;
    color: var(--color-text);
    border: 2px solid var(--color-border);
    padding: 16px 36px;
    border-radius: 10px;
    font-weight: 600;
    font-size: 17px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-outline:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

/* ===================================
   Section Styles
   =================================== */
section {
    padding: 120px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 80px;
}

.section-tag {
    display: inline-block;
    font-size: 14px;
    font-weight: 700;
    letter-spacing: 1px;
    text-transform: uppercase;
    color: var(--color-primary);
    margin-bottom: 16px;
}

.section-tag.light {
    color: rgba(255, 255, 255, 0.8);
}

.section-title {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    color: var(--color-text);
    margin-bottom: 16px;
}

.section-title.light {
    color: white;
}

.section-desc {
    font-size: 18px;
    color: var(--color-text-light);
    line-height: 1.7;
}

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

.about-intro {
    font-size: 20px;
    color: var(--color-text);
    line-height: 1.8;
    text-align: center;
    max-width: 900px;
    margin: 0 auto 64px;
}

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

.feature-item {
    display: flex;
    gap: 24px;
    padding: 32px;
    background: white;
    border: 1px solid var(--color-border);
    border-radius: 16px;
    transition: all 0.3s ease;
}

.feature-item:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.feature-icon {
    flex-shrink: 0;
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feature-icon svg {
    stroke: white;
}

.feature-text h4 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--color-text);
}

.feature-text p {
    font-size: 15px;
    color: var(--color-text-light);
    line-height: 1.6;
}

/* ===================================
   Platforms Section
   =================================== */
.platforms-section {
    background: var(--color-bg-light);
}

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

.platform-card {
    background: white;
    border: 1px solid var(--color-border);
    border-radius: 20px;
    padding: 40px;
    transition: all 0.3s ease;
    position: relative;
}

.platform-card:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-6px);
    border-color: var(--color-primary);
}

.platform-card.featured {
    border-width: 2px;
    border-color: var(--color-primary);
}

.platform-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 24px;
}

.platform-icon {
    width: 80px;
    height: 80px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #F8FAFC 0%, #EFF6FF 100%);
}

.platform-icon svg {
    stroke: var(--color-primary);
}

.platform-icon.msn svg {
    stroke: #00C73C;
}

.platform-icon.dv360 svg {
    stroke: #4285F4;
}

.platform-icon.toss svg {
    stroke: #1B5BEB;
}

.platform-badge {
    background: var(--color-bg-gray);
    padding: 6px 14px;
    border-radius: 50px;
    font-size: 12px;
    font-weight: 700;
    color: var(--color-text);
}

.platform-badge.premium {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: white;
}

.platform-title {
    font-size: 28px;
    font-weight: 800;
    margin-bottom: 12px;
    color: var(--color-text);
}

.platform-desc {
    font-size: 15px;
    color: var(--color-text-light);
    line-height: 1.7;
    margin-bottom: 32px;
}

.platform-features h4 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--color-text);
}

.platform-features ul {
    list-style: none;
    margin-bottom: 32px;
}

.platform-features li {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 0;
    font-size: 14px;
    color: var(--color-text);
}

.platform-features li svg {
    flex-shrink: 0;
    stroke: var(--color-success);
}

.platform-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    padding-top: 32px;
    border-top: 1px solid var(--color-border);
}

.platform-stats .stat {
    text-align: center;
}

.stat-label {
    font-size: 12px;
    color: var(--color-text-light);
    margin-bottom: 6px;
}

.stat-value {
    font-size: 28px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===================================
   Advantages Section
   =================================== */
.advantages-section {
    background: var(--color-bg);
}

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

.advantage-card {
    position: relative;
    padding: 40px 32px;
    background: white;
    border: 1px solid var(--color-border);
    border-radius: 20px;
    transition: all 0.3s ease;
}

.advantage-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.advantage-number {
    position: absolute;
    top: 32px;
    right: 32px;
    font-size: 48px;
    font-weight: 900;
    color: var(--color-bg-light);
}

.advantage-icon {
    width: 72px;
    height: 72px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

.advantage-icon svg {
    stroke: white;
}

.advantage-card h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--color-text);
}

.advantage-card p {
    font-size: 15px;
    color: var(--color-text-light);
    line-height: 1.7;
}

/* ===================================
   Cases Section
   =================================== */
.cases-section {
    background: var(--color-bg-light);
}

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

.case-card {
    background: white;
    border: 1px solid var(--color-border);
    border-radius: 20px;
    padding: 40px;
    transition: all 0.3s ease;
}

.case-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.case-header {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
}

.case-category {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: white;
    padding: 6px 16px;
    border-radius: 50px;
    font-size: 12px;
    font-weight: 700;
}

.case-platform {
    background: var(--color-bg-gray);
    padding: 6px 16px;
    border-radius: 50px;
    font-size: 12px;
    font-weight: 700;
    color: var(--color-text);
}

.case-title {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--color-text);
}

.case-desc {
    font-size: 15px;
    color: var(--color-text-light);
    line-height: 1.6;
    margin-bottom: 24px;
}

.case-results {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    padding-top: 24px;
    border-top: 1px solid var(--color-border);
}

.case-result {
    text-align: center;
}

.result-label {
    font-size: 12px;
    color: var(--color-text-light);
    margin-bottom: 6px;
}

.result-value {
    font-size: 24px;
    font-weight: 800;
    color: var(--color-text);
}

.result-value.highlight {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===================================
   Partner Section
   =================================== */
.partner-section {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.partner-section::before {
    content: '';
    position: absolute;
    top: -100px;
    right: -100px;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
}

.partner-content {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 80px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.partner-desc {
    font-size: 18px;
    line-height: 1.8;
    margin-bottom: 40px;
    opacity: 0.95;
}

.partner-benefits {
    display: grid;
    gap: 16px;
}

.benefit-item {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 16px;
    font-weight: 500;
}

.benefit-item svg {
    flex-shrink: 0;
    stroke: white;
}

.partner-form-wrapper {
    background: white;
    border-radius: 24px;
    padding: 48px;
    box-shadow: var(--shadow-xl);
}

.partner-form h3 {
    font-size: 28px;
    font-weight: 800;
    color: var(--color-text);
    margin-bottom: 8px;
}

.form-subtitle {
    font-size: 15px;
    color: var(--color-text-light);
    margin-bottom: 32px;
}

.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    font-weight: 600;
    font-size: 14px;
    color: var(--color-text);
    margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid var(--color-border);
    border-radius: 10px;
    font-size: 15px;
    font-family: inherit;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
    width: auto;
    cursor: pointer;
}

.submit-btn {
    width: 100%;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: white;
    border: none;
    padding: 18px 32px;
    border-radius: 10px;
    font-weight: 700;
    font-size: 17px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(37, 99, 235, 0.4);
}

.form-note {
    margin-top: 16px;
    font-size: 12px;
    color: var(--color-text-light);
    text-align: center;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--color-text);
    color: white;
    padding: 80px 0 32px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 3fr;
    gap: 64px;
    margin-bottom: 48px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.footer-brand img {
    display: block;
}

.footer-desc {
    font-size: 14px;
    opacity: 0.8;
}

.footer-info {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.footer-section h4 {
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 16px;
    opacity: 0.8;
}

.footer-section p {
    font-size: 14px;
    opacity: 0.7;
    line-height: 1.8;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 32px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    font-size: 13px;
    opacity: 0.7;
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    color: white;
    text-decoration: none;
    font-size: 13px;
    opacity: 0.7;
    transition: opacity 0.3s ease;
}

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

/* ===================================
   Back to Top
   =================================== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: white;
    border: none;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    transition: all 0.3s ease;
    z-index: 99;
}

.back-to-top.visible {
    display: flex;
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.back-to-top svg {
    stroke: white;
}

/* ===================================
   Responsive
   =================================== */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 48px;
    }
    
    .title-line {
        font-size: 36px;
    }
    
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .platforms-grid,
    .advantages-grid,
    .cases-grid {
        grid-template-columns: 1fr;
    }
    
    .about-features {
        grid-template-columns: 1fr;
    }
    
    .partner-content {
        grid-template-columns: 1fr;
        gap: 48px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-info {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }
    
    .nav-menu,
    .nav-actions {
        display: none;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .hero {
        padding: 140px 0 80px;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .title-line {
        font-size: 28px;
    }
    
    section {
        padding: 80px 0;
    }
    
    .section-title {
        font-size: 36px;
    }
    
    .hero-stats {
        grid-template-columns: 1fr;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .btn-large,
    .btn-outline {
        width: 100%;
        justify-content: center;
    }
    
    .case-results {
        grid-template-columns: 1fr;
    }
    
    .partner-form-wrapper {
        padding: 32px 24px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
}