:root {
    --primary: #1a56db;
    --primary-dark: #1041a8;
    --primary-light: #e8f0fe;
    --accent: #f59e0b;
    --accent-dark: #d97706;
    --dark: #111827;
    --gray-900: #1f2937;
    --gray-800: #374151;
    --gray-700: #4b5563;
    --gray-600: #6b7280;
    --gray-500: #9ca3af;
    --gray-400: #d1d5db;
    --gray-300: #e5e7eb;
    --gray-200: #f3f4f6;
    --gray-100: #f9fafb;
    --white: #ffffff;
    --radius: 12px;
    --radius-lg: 20px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow: 0 4px 20px rgba(0,0,0,0.08);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.12);
    --shadow-xl: 0 20px 60px rgba(0,0,0,0.15);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    color: var(--gray-800);
    line-height: 1.7;
    background: var(--white);
    overflow-x: hidden;
}

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

/* ==================== NAVBAR ==================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.06);
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(255,255,255,0.95);
    box-shadow: 0 2px 20px rgba(0,0,0,0.08);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.nav-logo {
    display: flex;
    flex-direction: column;
    text-decoration: none;
    line-height: 1.2;
}

.logo-icon {
    font-size: 22px;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: 2px;
}

.logo-sub {
    font-size: 9px;
    font-weight: 600;
    color: var(--gray-500);
    letter-spacing: 3px;
    text-transform: uppercase;
}

.nav-menu {
    display: flex;
    align-items: center;
    list-style: none;
    gap: 4px;
}

.nav-menu a {
    text-decoration: none;
    color: var(--gray-700);
    font-size: 14px;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 8px;
    transition: var(--transition);
}

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

.nav-cta {
    background: var(--primary) !important;
    color: var(--white) !important;
    padding: 8px 20px !important;
    border-radius: 8px !important;
    margin-left: 8px;
}

.nav-cta:hover {
    background: var(--primary-dark) !important;
    color: var(--white) !important;
}

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

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--gray-800);
    border-radius: 2px;
    transition: var(--transition);
}

/* ==================== HERO ==================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #1a365d 100%);
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(26, 86, 219, 0.3) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(59, 130, 246, 0.2) 0%, transparent 50%),
        radial-gradient(ellipse at 60% 80%, rgba(245, 158, 11, 0.1) 0%, transparent 50%);
}

.hero-particles {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.hero-particles .particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: rgba(255,255,255,0.15);
    border-radius: 50%;
    animation: float-particle linear infinite;
}

@keyframes float-particle {
    0% { transform: translateY(100vh) scale(0); opacity: 0; }
    10% { opacity: 1; }
    90% { opacity: 1; }
    100% { transform: translateY(-10vh) scale(1); opacity: 0; }
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 120px 24px 80px;
    max-width: 900px;
}

.hero-badge {
    display: inline-block;
    padding: 6px 20px;
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 50px;
    color: rgba(255,255,255,0.9);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 2px;
    margin-bottom: 28px;
    backdrop-filter: blur(10px);
}

.hero-title {
    margin-bottom: 20px;
}

.title-line {
    display: block;
    font-size: clamp(28px, 5vw, 48px);
    font-weight: 800;
    color: var(--white);
    letter-spacing: 4px;
    line-height: 1.3;
}

.hero-subtitle {
    font-size: clamp(18px, 3vw, 26px);
    color: var(--accent);
    font-weight: 600;
    letter-spacing: 8px;
    margin-bottom: 20px;
}

.hero-desc {
    font-size: 15px;
    color: rgba(255,255,255,0.7);
    line-height: 1.8;
    margin-bottom: 40px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 60px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: 10px;
    font-size: 15px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--primary);
    color: var(--white);
    box-shadow: 0 4px 15px rgba(26, 86, 219, 0.4);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(26, 86, 219, 0.5);
}

.btn-outline {
    background: transparent;
    color: var(--white);
    border: 2px solid rgba(255,255,255,0.3);
}

.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: rgba(255,255,255,0.6);
    transform: translateY(-2px);
}

.btn-lg {
    padding: 16px 40px;
    font-size: 16px;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    padding: 40px;
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(10px);
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: clamp(28px, 4vw, 42px);
    font-weight: 800;
    color: var(--white);
    line-height: 1;
}

.stat-suffix {
    font-size: clamp(16px, 2vw, 22px);
    font-weight: 700;
    color: var(--accent);
}

.stat-label {
    display: block;
    font-size: 12px;
    color: rgba(255,255,255,0.6);
    margin-top: 8px;
    letter-spacing: 1px;
}

.hero-scroll {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.hero-scroll a {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: rgba(255,255,255,0.5);
    font-size: 12px;
    letter-spacing: 2px;
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    border-right: 2px solid rgba(255,255,255,0.4);
    border-bottom: 2px solid rgba(255,255,255,0.4);
    transform: rotate(45deg);
    animation: scroll-bounce 2s ease-in-out infinite;
}

@keyframes scroll-bounce {
    0%, 100% { transform: rotate(45deg) translate(0, 0); }
    50% { transform: rotate(45deg) translate(5px, 5px); }
}

/* ==================== SECTIONS ==================== */
.section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-tag {
    display: inline-block;
    font-size: 12px;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: 4px;
    text-transform: uppercase;
    margin-bottom: 12px;
}

.section-title {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 800;
    color: var(--dark);
    margin-bottom: 16px;
    letter-spacing: 2px;
}

.section-line {
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    border-radius: 2px;
    margin: 0 auto;
}

.section-desc {
    font-size: 16px;
    color: var(--gray-600);
    margin-top: 16px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ==================== ABOUT ==================== */
.about {
    background: var(--gray-100);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-lead {
    font-size: 17px;
    color: var(--gray-900);
    margin-bottom: 16px;
    line-height: 1.8;
}

.about-text p {
    color: var(--gray-700);
    margin-bottom: 24px;
    font-size: 15px;
}

.about-highlights {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-top: 32px;
}

.highlight-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px;
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.highlight-item:hover {
    box-shadow: var(--shadow);
    transform: translateX(4px);
}

.highlight-icon {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    border-radius: 10px;
    color: var(--primary);
}

.highlight-icon svg {
    width: 22px;
    height: 22px;
}

.highlight-item h4 {
    font-size: 15px;
    color: var(--dark);
    margin-bottom: 2px;
}

.highlight-item p {
    font-size: 13px;
    color: var(--gray-600);
    margin: 0;
}

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

.about-card-stack {
    position: relative;
    width: 100%;
    max-width: 380px;
    height: 400px;
}

.info-card {
    position: absolute;
    width: 280px;
    padding: 32px;
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
}

.info-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.card-1 {
    top: 0;
    left: 0;
    z-index: 3;
    border-left: 4px solid var(--primary);
}

.card-2 {
    top: 120px;
    left: 80px;
    z-index: 2;
    border-left: 4px solid var(--accent);
}

.card-3 {
    top: 240px;
    left: 30px;
    z-index: 1;
    border-left: 4px solid #10b981;
}

.card-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    border-radius: 12px;
    color: var(--primary);
    margin-bottom: 16px;
}

.card-icon svg {
    width: 24px;
    height: 24px;
}

.info-card h4 {
    font-size: 16px;
    color: var(--dark);
    margin-bottom: 6px;
}

.info-card p {
    font-size: 14px;
    color: var(--gray-600);
}

/* ==================== ADVANTAGES ==================== */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.advantage-card {
    position: relative;
    padding: 40px;
    background: var(--white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-300);
    transition: var(--transition);
    overflow: hidden;
}

.advantage-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    opacity: 0;
    transition: var(--transition);
}

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

.advantage-card:hover::before {
    opacity: 1;
}

.advantage-number {
    position: absolute;
    top: 16px;
    right: 24px;
    font-size: 48px;
    font-weight: 900;
    color: var(--gray-200);
    line-height: 1;
}

.advantage-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    border-radius: 14px;
    color: var(--primary);
    margin-bottom: 20px;
}

.advantage-icon svg {
    width: 28px;
    height: 28px;
}

.advantage-card h3 {
    font-size: 20px;
    color: var(--dark);
    margin-bottom: 12px;
}

.advantage-card p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.8;
}

/* ==================== SERVICES ==================== */
.services {
    background: var(--gray-100);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.service-item {
    padding: 36px;
    background: var(--white);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition);
    border: 1px solid transparent;
}

.service-item:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.service-icon {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-light), #dbeafe);
    border-radius: 16px;
    color: var(--primary);
    margin: 0 auto 20px;
}

.service-icon svg {
    width: 30px;
    height: 30px;
}

.service-item h3 {
    font-size: 18px;
    color: var(--dark);
    margin-bottom: 12px;
}

.service-item p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.8;
}

/* ==================== CULTURE ==================== */
.culture-values {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-bottom: 48px;
}

.value-card {
    text-align: center;
    padding: 48px 32px;
    background: var(--white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-300);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.value-card::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    opacity: 0;
    transition: var(--transition);
}

.value-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.value-card:hover::after {
    opacity: 1;
}

.value-char {
    font-size: 64px;
    font-weight: 900;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
    margin-bottom: 8px;
}

.value-card h3 {
    font-size: 20px;
    color: var(--dark);
    margin-bottom: 16px;
}

.value-card p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.8;
}

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

.culture-block {
    padding: 40px;
    background: var(--gray-100);
    border-radius: var(--radius-lg);
    border: 1px solid var(--gray-300);
    transition: var(--transition);
}

.culture-block:hover {
    box-shadow: var(--shadow);
    transform: translateY(-4px);
}

.culture-block-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    border-radius: 12px;
    color: var(--primary);
    margin-bottom: 16px;
}

.culture-block-icon svg {
    width: 24px;
    height: 24px;
}

.culture-block h3 {
    font-size: 14px;
    color: var(--primary);
    font-weight: 600;
    letter-spacing: 2px;
    margin-bottom: 4px;
}

.culture-block h4 {
    font-size: 20px;
    color: var(--dark);
    margin-bottom: 12px;
}

.culture-block p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.8;
}

/* ==================== HISTORY ==================== */
.history {
    background: var(--gray-100);
}

.timeline {
    position: relative;
    max-width: 700px;
    margin: 0 auto;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--primary), var(--accent));
}

.timeline-item {
    position: relative;
    padding-bottom: 48px;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: -33px;
    top: 6px;
    width: 16px;
    height: 16px;
    background: var(--primary);
    border-radius: 50%;
    border: 3px solid var(--white);
    box-shadow: 0 0 0 3px var(--primary);
}

.timeline-content {
    background: var(--white);
    padding: 28px 32px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-300);
    transition: var(--transition);
}

.timeline-content:hover {
    box-shadow: var(--shadow);
    transform: translateX(4px);
}

.timeline-year {
    display: inline-block;
    padding: 4px 14px;
    background: var(--primary-light);
    color: var(--primary);
    font-size: 13px;
    font-weight: 700;
    border-radius: 6px;
    margin-bottom: 12px;
}

.timeline-content h3 {
    font-size: 18px;
    color: var(--dark);
    margin-bottom: 8px;
}

.timeline-content p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.8;
}

/* ==================== CERTIFICATIONS ==================== */
.cert-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.cert-category-title {
    font-size: 20px;
    color: var(--dark);
    margin-bottom: 24px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--primary);
    display: inline-block;
}

.cert-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.cert-item {
    display: flex;
    gap: 16px;
    padding: 24px;
    background: var(--gray-100);
    border-radius: var(--radius);
    transition: var(--transition);
}

.cert-item:hover {
    background: var(--white);
    box-shadow: var(--shadow);
    transform: translateX(4px);
}

.cert-badge {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 12px;
    color: var(--white);
}

.cert-badge svg {
    width: 24px;
    height: 24px;
}

.cert-badge-alt {
    background: linear-gradient(135deg, #10b981, #059669);
}

.cert-info h4 {
    font-size: 16px;
    color: var(--dark);
    margin-bottom: 6px;
}

.cert-info p {
    font-size: 13px;
    color: var(--gray-600);
    line-height: 1.7;
}

/* ==================== PROMISE ==================== */
.promise {
    background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 100%);
    padding: 80px 0;
}

.promise-content {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

.promise-icon {
    width: 72px;
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(245, 158, 11, 0.15);
    border-radius: 50%;
    color: var(--accent);
    margin: 0 auto 24px;
}

.promise-icon svg {
    width: 36px;
    height: 36px;
}

.promise-content h2 {
    font-size: 32px;
    color: var(--white);
    margin-bottom: 20px;
    letter-spacing: 2px;
}

.promise-content p {
    font-size: 16px;
    color: rgba(255,255,255,0.75);
    line-height: 2;
}

/* ==================== CONTACT ==================== */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-card {
    display: flex;
    gap: 16px;
    padding: 24px;
    background: var(--gray-100);
    border-radius: var(--radius);
    transition: var(--transition);
}

.contact-card:hover {
    background: var(--white);
    box-shadow: var(--shadow);
    transform: translateX(4px);
}

.contact-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    border-radius: 12px;
    color: var(--primary);
}

.contact-icon svg {
    width: 24px;
    height: 24px;
}

.contact-card h4 {
    font-size: 16px;
    color: var(--dark);
    margin-bottom: 4px;
}

.contact-card p {
    font-size: 14px;
    color: var(--gray-700);
}

.contact-sub {
    color: var(--gray-500) !important;
    font-size: 13px !important;
}

.cta-box {
    padding: 48px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: var(--radius-lg);
    color: var(--white);
    text-align: center;
}

.cta-box h3 {
    font-size: 22px;
    margin-bottom: 8px;
}

.cta-box > p {
    font-size: 15px;
    opacity: 0.85;
    margin-bottom: 28px;
}

.cta-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 32px;
    text-align: left;
}

.cta-feature {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
}

.cta-feature svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
    color: var(--accent);
}

.cta-box .btn-primary {
    background: var(--white);
    color: var(--primary);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.cta-box .btn-primary:hover {
    background: var(--gray-100);
    transform: translateY(-2px);
}

/* ==================== FOOTER ==================== */
.footer {
    background: var(--dark);
    padding: 60px 0 0;
    color: rgba(255,255,255,0.7);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.footer-brand p {
    font-size: 14px;
    margin-top: 12px;
}

.footer-slogan {
    color: var(--accent) !important;
    font-weight: 600;
    letter-spacing: 2px;
    margin-top: 4px !important;
}

.footer-brand .logo-icon {
    color: var(--white);
}

.footer-brand .logo-sub {
    color: rgba(255,255,255,0.4);
}

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

.footer-col h4 {
    font-size: 15px;
    color: var(--white);
    margin-bottom: 16px;
    font-weight: 600;
}

.footer-col ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-col a {
    text-decoration: none;
    color: rgba(255,255,255,0.6);
    font-size: 14px;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding: 24px 0;
    font-size: 13px;
    color: rgba(255,255,255,0.4);
}

/* ==================== BACK TO TOP ==================== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
}

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

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
}

.back-to-top svg {
    width: 22px;
    height: 22px;
}

/* ==================== ANIMATIONS ==================== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 1024px) {
    .about-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .about-visual {
        order: -1;
    }

    .about-card-stack {
        height: auto;
        display: flex;
        flex-direction: column;
        gap: 16px;
        max-width: 100%;
    }

    .info-card {
        position: static;
        width: 100%;
    }

    .advantages-grid {
        grid-template-columns: 1fr;
    }

    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .cert-grid {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 24px;
        gap: 8px;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-menu a {
        display: block;
        padding: 12px 16px;
        font-size: 16px;
    }

    .nav-cta {
        text-align: center;
        margin-left: 0 !important;
    }

    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
        padding: 24px;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .services-grid {
        grid-template-columns: 1fr;
    }

    .culture-values {
        grid-template-columns: 1fr;
    }

    .culture-extra {
        grid-template-columns: 1fr;
    }

    .cta-features {
        grid-template-columns: 1fr;
    }

    .footer-links {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .section {
        padding: 60px 0;
    }
}

@media (max-width: 480px) {
    .hero-content {
        padding: 100px 16px 60px;
    }

    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
        padding: 20px;
    }

    .stat-number {
        font-size: 28px;
    }

    .cta-box {
        padding: 32px 24px;
    }
}