/* ========================================
   NKT Audit - Landing Page Styles
   Modern, Minimal, Clean Design
   Base: White + Dark Navy Blue
   ======================================== */

/* CSS Variables */
:root {
    --primary: #0A2540;
    --primary-light: #123a5f;
    --primary-dark: #061827;
    --accent: #D4AF37;
    --accent-light: #E8C84A;
    --white: #FFFFFF;
    --gray-50: #F8FAFC;
    --gray-100: #F1F5F9;
    --gray-200: #E2E8F0;
    --gray-400: #94A3B8;
    --gray-600: #475569;
    --gray-800: #1E293B;
    --black: #0F172A;
    --success: #10B981;
    --shadow-sm: 0 1px 2px 0 rgba(10, 37, 64, 0.05);
    --shadow: 0 4px 6px -1px rgba(10, 37, 64, 0.1), 0 2px 4px -1px rgba(10, 37, 64, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(10, 37, 64, 0.1), 0 4px 6px -2px rgba(10, 37, 64, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(10, 37, 64, 0.1), 0 10px 10px -5px rgba(10, 37, 64, 0.04);
    --radius-sm: 8px;
    --radius: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
    font-family: 'Inter', 'Noto Sans Thai', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--gray-800);
    line-height: 1.7;
    background-color: var(--white);
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

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

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 100px 0;
    position: relative;
}

.section-gray {
    background-color: var(--gray-50);
}

/* Typography */
h1, h2, h3, h4 {
    color: var(--primary);
    line-height: 1.3;
    font-weight: 700;
}

p {
    color: var(--gray-600);
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
}

.section-tag {
    display: inline-block;
    padding: 8px 20px;
    background: linear-gradient(135deg, rgba(10, 37, 64, 0.08), rgba(10, 37, 64, 0.04));
    color: var(--primary);
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    border-radius: 50px;
    margin-bottom: 16px;
    text-transform: uppercase;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--gray-600);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 50px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--white);
    box-shadow: 0 4px 14px rgba(10, 37, 64, 0.25);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(10, 37, 64, 0.35);
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary) 100%);
}

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

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

.btn-full {
    width: 100%;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(10, 37, 64, 0.05);
    transition: var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow);
    background: rgba(255, 255, 255, 0.98);
}

.navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-img {
    width: 50px;
    height: 50px;
    object-fit: contain;
    transition: var(--transition);
}

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

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1.2;
}

.logo-sub {
    font-size: 0.8rem;
    color: var(--gray-400);
    font-weight: 500;
    line-height: 1.2;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--gray-600);
    position: relative;
    padding: 8px 0;
}

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

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

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

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

.lang-switcher {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--gray-50);
    padding: 4px;
    border-radius: 50px;
    border: 1px solid var(--gray-200);
}

.lang-switcher-mobile {
    display: none;
}

.lang-btn {
    background: transparent;
    border: none;
    padding: 6px 14px;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--gray-400);
    cursor: pointer;
    border-radius: 50px;
    transition: var(--transition);
    font-family: inherit;
}

.lang-btn.active {
    background: var(--primary);
    color: var(--white);
    box-shadow: var(--shadow-sm);
}

.lang-btn:hover:not(.active) {
    color: var(--primary);
}

.lang-divider {
    color: var(--gray-400);
    font-size: 0.75rem;
}

.hamburger {
    display: none;
    flex-direction: column;
    justify-content: space-around;
    width: 28px;
    height: 24px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
}

.hamburger span {
    width: 100%;
    height: 2px;
    background: var(--primary);
    border-radius: 2px;
    transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, var(--white) 0%, #f0f4f8 100%);
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 0;
}

.hero-shape {
    position: absolute;
    border-radius: 50%;
    opacity: 0.08;
    background: var(--primary);
}

.shape-1 {
    width: 600px;
    height: 600px;
    top: -200px;
    right: -100px;
    animation: float 8s ease-in-out infinite;
}

.shape-2 {
    width: 400px;
    height: 400px;
    bottom: -150px;
    left: -100px;
    background: var(--accent);
    opacity: 0.1;
    animation: float 10s ease-in-out infinite reverse;
}

.shape-3 {
    width: 200px;
    height: 200px;
    top: 40%;
    right: 20%;
    opacity: 0.05;
    animation: float 12s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-30px) rotate(5deg); }
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 10px 20px;
    background: rgba(212, 175, 55, 0.12);
    color: var(--accent);
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 24px;
    animation: fadeInDown 0.8s ease-out;
}

.hero-badge i {
    color: var(--accent);
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 24px;
    line-height: 1.2;
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-title .highlight {
    display: block;
    color: var(--accent);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--gray-600);
    margin-bottom: 32px;
    max-width: 540px;
    animation: fadeInUp 0.8s ease-out 0.4s both;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
    animation: fadeInUp 0.8s ease-out 0.6s both;
}

.hero-stats {
    display: flex;
    gap: 40px;
    animation: fadeInUp 0.8s ease-out 0.8s both;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1.2;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--gray-600);
    font-weight: 500;
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-logo-wrapper {
    position: relative;
    width: 380px;
    height: 380px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-logo {
    width: 280px;
    height: 280px;
    object-fit: contain;
    position: relative;
    z-index: 2;
    animation: sail 6s ease-in-out infinite;
    filter: drop-shadow(0 20px 40px rgba(10, 37, 64, 0.15));
}

@keyframes sail {
    0%, 100% { transform: translateY(0) rotate(-2deg); }
    50% { transform: translateY(-20px) rotate(2deg); }
}

.hero-logo-ring {
    position: absolute;
    width: 100%;
    height: 100%;
    border: 2px solid rgba(10, 37, 64, 0.08);
    border-radius: 50%;
    animation: pulse 4s ease-in-out infinite;
}

.hero-logo-ring.ring-2 {
    width: 85%;
    height: 85%;
    border-color: rgba(212, 175, 55, 0.15);
    animation-delay: 1s;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.05); opacity: 1; }
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.scroll-mouse {
    width: 26px;
    height: 40px;
    border: 2px solid var(--primary);
    border-radius: 13px;
    position: relative;
    opacity: 0.5;
}

.scroll-mouse span {
    position: absolute;
    width: 4px;
    height: 8px;
    background: var(--primary);
    border-radius: 2px;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollDown 2s infinite;
}

@keyframes scrollDown {
    0% { opacity: 1; top: 8px; }
    100% { opacity: 0; top: 22px; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 80px;
    align-items: center;
}

.about-img-wrapper {
    position: relative;
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--white) 100%);
    border-radius: var(--radius-xl);
    padding: 40px;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: var(--shadow-xl);
}

.about-img-wrapper img {
    max-width: 280px;
    filter: drop-shadow(0 10px 30px rgba(10, 37, 64, 0.12));
}

.about-experience {
    position: absolute;
    bottom: -20px;
    right: -20px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--white);
    padding: 24px 32px;
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-lg);
    animation: float 5s ease-in-out infinite;
}

.about-exp-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1;
}

.about-exp-text {
    font-size: 0.9rem;
    opacity: 0.9;
}

.about-content h3 {
    font-size: 2rem;
    margin-bottom: 24px;
}

.about-content p {
    margin-bottom: 16px;
    font-size: 1.05rem;
}

.about-features {
    margin-top: 32px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.about-feature {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.feature-icon {
    width: 48px;
    height: 48px;
    min-width: 48px;
    background: rgba(10, 37, 64, 0.06);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 1.25rem;
}

.feature-text h4 {
    font-size: 1.1rem;
    margin-bottom: 4px;
}

.feature-text p {
    font-size: 0.95rem;
    margin: 0;
}

/* Services Section */
.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.service-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 40px 28px;
    box-shadow: var(--shadow);
    border: 1px solid var(--gray-100);
    transition: var(--transition-slow);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition-slow);
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.service-card:hover::before {
    transform: scaleX(1);
}

.service-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, rgba(10, 37, 64, 0.08) 0%, rgba(10, 37, 64, 0.03) 100%);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    color: var(--primary);
    margin-bottom: 24px;
    transition: var(--transition);
}

.service-card:hover .service-icon {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--white);
    transform: scale(1.1);
}

.service-card h3 {
    font-size: 1.25rem;
    margin-bottom: 12px;
}

.service-card p {
    font-size: 0.95rem;
    margin-bottom: 20px;
}

.service-link {
    color: var(--primary);
    font-weight: 600;
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.service-link i {
    transition: var(--transition);
}

.service-link:hover {
    color: var(--accent);
}

.service-link:hover i {
    transform: translateX(5px);
}

/* Partner Section */
.partner-wrapper {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    border-radius: var(--radius-xl);
    padding: 80px;
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 60px;
    align-items: center;
    color: var(--white);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.partner-wrapper::before {
    content: '';
    position: absolute;
    top: -100px;
    right: -100px;
    width: 300px;
    height: 300px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 50%;
}

.partner-wrapper::after {
    content: '';
    position: absolute;
    bottom: -150px;
    left: -150px;
    width: 400px;
    height: 400px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 50%;
}

.partner-content {
    position: relative;
    z-index: 1;
}

.partner-content .section-tag {
    background: rgba(255, 255, 255, 0.12);
    color: var(--white);
}

.partner-content .section-title {
    color: var(--white);
    margin-bottom: 20px;
}

.partner-content p {
    color: rgba(255, 255, 255, 0.85);
    font-size: 1.1rem;
    margin-bottom: 28px;
}

.partner-features {
    display: flex;
    flex-direction: column;
    gap: 14px;
    margin-bottom: 32px;
}

.partner-features li {
    display: flex;
    align-items: center;
    gap: 12px;
    color: rgba(255, 255, 255, 0.9);
}

.partner-features i {
    color: var(--accent);
    font-size: 1.1rem;
}

.partner-content .btn-primary {
    background: var(--white);
    color: var(--primary);
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.2);
}

.partner-content .btn-primary:hover {
    background: var(--accent);
    color: var(--white);
}

.partner-logo {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    z-index: 1;
}

.partner-badge {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 40px;
    text-align: center;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
    transition: var(--transition);
}

.partner-badge:hover {
    transform: translateY(-10px);
}

.partner-label {
    display: block;
    color: var(--accent);
    font-weight: 700;
    font-size: 0.875rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-bottom: 20px;
}

.partner-img {
    max-width: 220px;
    margin: 0 auto;
}

/* Why Choose Us Section */
.why-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.why-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    box-shadow: var(--shadow);
    border: 1px solid var(--gray-100);
    transition: var(--transition);
    text-align: center;
}

.why-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent);
}

.why-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, rgba(10, 37, 64, 0.08) 0%, rgba(10, 37, 64, 0.02) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    color: var(--primary);
    margin: 0 auto 20px;
    transition: var(--transition);
}

.why-card:hover .why-icon {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--white);
    transform: rotateY(360deg);
}

.why-card h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.why-card p {
    font-size: 0.95rem;
}

/* Contact Section */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
}

.contact-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow);
    border: 1px solid var(--gray-100);
}

.contact-item {
    display: flex;
    gap: 20px;
    margin-bottom: 28px;
}

.contact-item:last-child {
    margin-bottom: 0;
}

.contact-icon {
    width: 52px;
    height: 52px;
    min-width: 52px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--white);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.contact-text h4 {
    font-size: 0.95rem;
    color: var(--gray-400);
    font-weight: 600;
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.contact-text p {
    color: var(--gray-800);
    font-weight: 500;
    line-height: 1.6;
}

.contact-text a {
    color: var(--primary);
    font-weight: 600;
}

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

.contact-en {
    color: var(--gray-400) !important;
    font-size: 0.9rem;
    margin-top: 2px;
}

.contact-form-wrapper {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow);
    border: 1px solid var(--gray-100);
}

.contact-form h3 {
    font-size: 1.5rem;
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 1rem;
    color: var(--gray-800);
    background: var(--white);
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(10, 37, 64, 0.08);
}

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

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

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1.5fr;
    gap: 40px;
    padding-bottom: 60px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
}

.footer-logo img {
    width: 50px;
    height: 50px;
    object-fit: contain;
    background: var(--white);
    border-radius: 12px;
    padding: 4px;
}

.footer-name {
    display: block;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--white);
}

.footer-sub {
    display: block;
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.7);
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
    line-height: 1.7;
}

.footer-links h4,
.footer-services h4,
.footer-contact h4 {
    color: var(--white);
    font-size: 1.1rem;
    margin-bottom: 24px;
}

.footer-links li,
.footer-services li {
    margin-bottom: 12px;
}

.footer-links a,
.footer-services a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
    transition: var(--transition);
}

.footer-links a:hover,
.footer-services a:hover {
    color: var(--accent);
    padding-left: 5px;
}

.footer-contact p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
    margin-bottom: 12px;
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.footer-contact i {
    color: var(--accent);
    margin-top: 5px;
    min-width: 16px;
}

.footer-contact a {
    color: rgba(255, 255, 255, 0.7);
}

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

.footer-bottom {
    padding: 24px 0;
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
}

.back-to-top.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--accent);
    transform: translateY(-5px);
}

/* ========================================
   Responsive Design
   ======================================== */

/* Tablet */
@media screen and (max-width: 1024px) {
    .section {
        padding: 80px 0;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .hero-title {
        font-size: 2.75rem;
    }
    
    .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }
    
    .hero-content {
        order: 2;
    }
    
    .hero-image {
        order: 1;
    }
    
    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .hero-logo-wrapper {
        width: 300px;
        height: 300px;
    }
    
    .hero-logo {
        width: 220px;
        height: 220px;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
        gap: 60px;
    }
    
    .about-image {
        max-width: 500px;
        margin: 0 auto;
    }
    
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .partner-wrapper {
        grid-template-columns: 1fr;
        padding: 60px;
        text-align: center;
    }
    
    .partner-features {
        align-items: center;
    }
    
    .why-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Mobile */
@media screen and (max-width: 768px) {
    .container {
        padding: 0 20px;
    }
    
    .section {
        padding: 60px 0;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .section-subtitle {
        font-size: 1rem;
    }
    
    .navbar {
        height: 70px;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--white);
        flex-direction: column;
        justify-content: flex-start;
        padding: 40px 24px;
        gap: 24px;
        transform: translateX(100%);
        transition: var(--transition-slow);
        box-shadow: var(--shadow-xl);
        z-index: 999;
        overflow-y: auto;
    }
    
    .nav-menu.active {
        transform: translateX(0);
    }
    
    .nav-link {
        font-size: 1.25rem;
        padding: 12px 0;
    }
    
    .nav-cta {
        display: none;
    }
    
    .lang-switcher {
        display: none;
    }
    
    .lang-switcher-mobile {
        display: flex;
        align-items: center;
        gap: 8px;
        margin-top: 20px;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero {
        min-height: auto;
        padding: 120px 0 80px;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .hero-subtitle {
        font-size: 1.05rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        gap: 12px;
    }
    
    .hero-buttons .btn {
        width: 100%;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 20px;
        align-items: center;
    }
    
    .stat-item {
        align-items: center;
    }
    
    .hero-logo-wrapper {
        width: 260px;
        height: 260px;
    }
    
    .hero-logo {
        width: 180px;
        height: 180px;
    }
    
    .about-img-wrapper {
        padding: 30px;
    }
    
    .about-img-wrapper img {
        max-width: 200px;
    }
    
    .about-experience {
        padding: 16px 24px;
        right: 0;
    }
    
    .about-exp-number {
        font-size: 2rem;
    }
    
    .about-features {
        gap: 16px;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .partner-wrapper {
        padding: 40px 24px;
    }
    
    .partner-content .section-title {
        font-size: 1.75rem;
    }
    
    .partner-badge {
        padding: 30px 20px;
    }
    
    .partner-img {
        max-width: 180px;
    }
    
    .why-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-card,
    .contact-form-wrapper {
        padding: 28px 20px;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    
    .footer-logo {
        justify-content: center;
    }
    
    .footer-contact p {
        justify-content: center;
    }
    
    .footer-bottom {
        padding: 20px 0;
    }
    
    .back-to-top {
        width: 44px;
        height: 44px;
        bottom: 20px;
        right: 20px;
    }
}

/* Small Mobile */
@media screen and (max-width: 480px) {
    .hero-title {
        font-size: 1.85rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .logo-img {
        width: 42px;
        height: 42px;
    }
    
    .logo-name {
        font-size: 1.1rem;
    }
    
    .hero-logo-wrapper {
        width: 220px;
        height: 220px;
    }
    
    .hero-logo {
        width: 150px;
        height: 150px;
    }
    
    .partner-content .btn-primary {
        width: 100%;
    }
}

/* ========================================
   Animation Utilities
   ======================================== */

[data-aos] {
    will-change: transform, opacity;
}

/* Language transition effect */
[data-i18n] {
    transition: opacity 0.2s ease;
}

body.switching-lang [data-i18n] {
    opacity: 0.7;
}