/* ============================================
   RWDI & CNP Partnership Website
   Main Stylesheet
   ============================================ */

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

:root {
    /* Color Palette */
    --primary-blue: #0066b2;
    --primary-red: #e63946;
    --dark-gray: #1a1a1a;
    --medium-gray: #4a4a4a;
    --light-gray: #f5f5f5;
    --white: #ffffff;
    --accent-blue: #0077cc;
    --accent-light: #e8f4fd;
    
    /* Typography */
    --font-en: 'Inter', sans-serif;
    --font-ko: 'Noto Sans KR', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-ko), var(--font-en);
    color: var(--dark-gray);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: var(--transition-normal);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.logo {
    height: 50px;
    width: auto;
    object-fit: contain;
}

.logo-rwdi {
    height: 50px;
}

.logo-cnp {
    height: 30px;
}

.logo-divider {
    font-size: 1.5rem;
    color: var(--medium-gray);
    font-weight: 300;
}

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

.nav-link {
    color: var(--medium-gray);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-fast);
    padding: 0.5rem 0;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-blue);
    transition: var(--transition-fast);
}

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

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

/* Dropdown Menu */
.nav-dropdown {
    position: relative;
}

.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--white);
    min-width: 180px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    border-radius: 8px;
    padding: 0.5rem 0;
    margin-top: 0.5rem;
    z-index: 1000;
}

.nav-dropdown:hover .dropdown-content {
    display: block;
}

.dropdown-content a {
    color: var(--dark-gray);
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    display: block;
    transition: var(--transition-fast);
    font-weight: 500;
}

.dropdown-content a:hover {
    background: var(--accent-light);
    color: var(--primary-blue);
}

.lang-toggle {
    background: none;
    border: 1px solid var(--medium-gray);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition-fast);
}

.lang-toggle:hover {
    border-color: var(--primary-blue);
}

.lang-option {
    color: var(--medium-gray);
    transition: var(--transition-fast);
}

.lang-option.active {
    color: var(--primary-blue);
    font-weight: 700;
}

.lang-divider {
    color: var(--medium-gray);
    margin: 0 0.25rem;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--dark-gray);
    cursor: pointer;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    padding-top: 80px;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--accent-blue) 100%);
    opacity: 0.95;
}

.hero-background::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        repeating-linear-gradient(45deg, transparent, transparent 35px, rgba(255,255,255,0.03) 35px, rgba(255,255,255,0.03) 70px);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: var(--white);
    padding: var(--spacing-lg) var(--spacing-md);
    max-width: 1000px;
    margin: 0 auto;
}

.hero-title {
    font-size: clamp(1.5rem, 4vw, 3.5rem);
    font-weight: 800;
    margin-bottom: var(--spacing-md);
    line-height: 1.3;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
    white-space: normal;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

/* Korean version - single line */
.hero-title[data-ko]:not([data-en="Engineering Excellence for High-Performance Buildings"]) {
    white-space: nowrap;
}

/* When Korean is displayed */
html[lang="ko"] .hero-title {
    white-space: nowrap;
}

/* When English is displayed */
html[lang="en"] .hero-title {
    white-space: normal;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
    opacity: 0.95;
}

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

.btn {
    display: inline-block;
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-normal);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

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

.btn-large {
    padding: 1.25rem 3rem;
    font-size: 1.125rem;
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-md);
    left: 50%;
    transform: translateX(-50%);
    color: var(--white);
    font-size: 2rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

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

.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    color: var(--dark-gray);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--medium-gray);
    max-width: 600px;
    margin: 0 auto;
}

/* Featured Services Section */
.featured-services {
    padding: var(--spacing-xl) 0;
    background: var(--light-gray);
}

.featured-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-lg);
}

.featured-card {
    background: var(--white);
    border-radius: 20px;
    padding: var(--spacing-lg);
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    transition: var(--transition-normal);
    display: flex;
    flex-direction: column;
}

.featured-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 50px rgba(0,0,0,0.15);
}

.featured-card[data-service="structural"] .featured-card-icon {
    background: linear-gradient(135deg, #0066b2, #0099ff);
}

.featured-card[data-service="wind-tunnel"] .featured-card-icon {
    background: linear-gradient(135deg, #00b8a9, #00d9c8);
}

.featured-card[data-service="stack-effect"] .featured-card-icon {
    background: linear-gradient(135deg, #e63946, #ff6b6b);
}

.featured-card-icon {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
    color: var(--white);
    font-size: 2rem;
}

.featured-card-content h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--dark-gray);
}

.featured-card-content p {
    color: var(--medium-gray);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.featured-list {
    list-style: none;
    margin-bottom: var(--spacing-md);
}

.featured-list li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--medium-gray);
}

.featured-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-blue);
    font-weight: bold;
}

.featured-link {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: auto;
    transition: var(--transition-fast);
}

.featured-link:hover {
    gap: 1rem;
}

/* All Services Section */
.all-services {
    padding: var(--spacing-xl) 0;
    background: var(--white);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.service-card {
    background: var(--white);
    border: 2px solid var(--light-gray);
    border-radius: 15px;
    padding: var(--spacing-md);
    text-decoration: none;
    color: var(--dark-gray);
    transition: var(--transition-normal);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.service-card:hover {
    border-color: var(--primary-blue);
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,102,178,0.1);
}

.service-card.highlight {
    border-color: var(--primary-blue);
    background: var(--accent-light);
}

.service-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-blue));
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.service-card h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
    font-weight: 700;
}

.service-card p {
    color: var(--medium-gray);
    font-size: 0.95rem;
    line-height: 1.5;
}

/* MOU Section */
.mou-section {
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
}

.mou-section .section-title {
    text-align: center;
    margin-bottom: var(--spacing-lg);
    color: var(--dark-gray);
}

.mou-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: start;
}

.mou-image {
    position: relative;
}

.mou-image img {
    width: 100%;
    height: auto;
    border-radius: 15px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.15);
}

.mou-caption {
    margin-top: var(--spacing-sm);
    font-size: 0.9rem;
    color: var(--medium-gray);
    text-align: center;
    line-height: 1.5;
}

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

/* MOU Ceremony Info */
.mou-ceremony-info {
    background: white;
    padding: var(--spacing-md);
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}

.mou-ceremony-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-sm);
}

.mou-ceremony-title i {
    font-size: 1.75rem;
}

.mou-date {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.05rem;
    color: var(--medium-gray);
    margin: 0;
}

.mou-date i {
    color: var(--primary-blue);
}

/* MOU Description Box */
.mou-description-box {
    background: white;
    padding: var(--spacing-md);
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}

.mou-subtitle {
    font-size: 1.25rem;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-sm);
    font-weight: 700;
}

.mou-text {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--dark-gray);
    margin: 0;
}

/* MOU Benefits */
.mou-benefits {
    background: white;
    padding: var(--spacing-md);
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}

.benefits-title {
    font-size: 1.25rem;
    color: var(--primary-blue);
    margin-bottom: var(--spacing-md);
    font-weight: 700;
}

.benefits-grid {
    display: grid;
    gap: var(--spacing-sm);
}

.benefit-card {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    border-radius: 8px;
    border-left: 4px solid var(--primary-blue);
    transition: var(--transition-normal);
}

.benefit-card:hover {
    transform: translateX(5px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.benefit-icon {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-blue);
    color: white;
    border-radius: 8px;
    font-size: 1.25rem;
}

.benefit-card p {
    margin: 0;
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--dark-gray);
    align-self: center;
}

/* About Section */
.about {
    padding: var(--spacing-xl) 0;
    background: var(--dark-gray);
    color: var(--white);
}

.about .section-title {
    color: var(--white);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
}

.about-text {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
    opacity: 0.9;
}

.about-features {
    display: grid;
    gap: var(--spacing-md);
}

.about-feature {
    display: flex;
    gap: var(--spacing-sm);
    align-items: flex-start;
}

.about-feature i {
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-top: 0.25rem;
}

.about-feature h4 {
    font-size: 1.125rem;
    margin-bottom: 0.25rem;
}

.about-feature p {
    opacity: 0.8;
    font-size: 0.95rem;
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.stat-card {
    background: rgba(255,255,255,0.1);
    padding: var(--spacing-md);
    border-radius: 15px;
    text-align: center;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.1);
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary-blue);
    line-height: 1;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.95rem;
    opacity: 0.9;
}

/* CTA Section */
.cta {
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, var(--primary-blue), var(--accent-blue));
    color: var(--white);
    text-align: center;
}

.cta-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
}

.cta-text {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.95;
}

/* Contact Section */
.contact {
    padding: var(--spacing-xl) 0;
    background: var(--light-gray);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--spacing-lg);
}

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

.contact-info p {
    color: var(--medium-gray);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.contact-item {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    align-items: flex-start;
}

.contact-item i {
    font-size: 1.5rem;
    color: var(--primary-blue);
    margin-top: 0.25rem;
}

.contact-item h4 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.contact-item p {
    margin: 0;
    color: var(--medium-gray);
}

.contact-form {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--dark-gray);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.875rem;
    border: 2px solid var(--light-gray);
    border-radius: 10px;
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition-fast);
}

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

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

/* Footer */
.footer {
    background: var(--dark-gray);
    color: var(--white);
    padding: var(--spacing-lg) 0;
}

.footer-content {
    text-align: center;
}

.footer-logos {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.footer-logo {
    height: 40px;
    width: auto;
    object-fit: contain;
    filter: brightness(0) invert(1);
    opacity: 0.8;
}

.footer-logo-cnp {
    height: 50px;
    filter: none;
    opacity: 1;
}

.footer-divider {
    font-size: 1.25rem;
    color: rgba(255,255,255,0.5);
}

.footer-text p {
    opacity: 0.7;
    margin: 0.25rem 0;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .mou-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .benefit-card {
        flex-direction: column;
        text-align: center;
    }
    
    .benefit-icon {
        margin: 0 auto;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: var(--spacing-md);
        box-shadow: 0 10px 30px rgba(0,0,0,0.1);
        transition: var(--transition-normal);
        align-items: flex-start;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .featured-grid {
        grid-template-columns: 1fr;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        grid-template-columns: 1fr 1fr;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
    
    .hero-title {
        white-space: normal;
        font-size: clamp(1.5rem, 5vw, 2.5rem);
    }
}

@media (max-width: 480px) {
    :root {
        font-size: 14px;
    }
    
    .logo {
        height: 40px;
    }
    
    .logo-rwdi {
        height: 40px;
    }
    
    .logo-cnp {
        height: 24px;
    }
    
    .footer-logo-cnp {
        height: 40px;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .stat-number {
        font-size: 2.5rem;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.6s ease forwards;
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }

.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }

/* Print Styles */
@media print {
    .navbar,
    .hero,
    .cta,
    .contact,
    .footer {
        display: none;
    }
}