/* ========================================
   CSS Variables & Reset
   ======================================== */
:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1e3a5f;
    --color-primary-light: #dbeafe;
    --color-primary-50: #eff6ff;
    --color-accent: #0ea5e9;
    --color-success: #10b981;
    --color-dark: #0f172a;
    --color-text: #334155;
    --color-text-light: #64748b;
    --color-border: #e2e8f0;
    --color-bg: #ffffff;
    --color-bg-alt: #f8fafc;
    --font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --radius: 12px;
    --radius-lg: 20px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.08);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.1);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --container-width: 1200px;
}

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

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

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

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

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

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ========================================
   Header
   ======================================== */
.header {
    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 transparent;
    transition: var(--transition);
}

.header.scrolled {
    background: rgba(255,255,255,0.95);
    border-bottom-color: var(--color-border);
    box-shadow: var(--shadow-sm);
}

.header-inner {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--color-dark);
}

.logo-icon {
    display: flex;
    width: 36px;
    height: 36px;
    color: var(--color-primary);
}

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

.logo-text {
    letter-spacing: 0.02em;
}

.nav {
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav-link {
    padding: 8px 16px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text);
    border-radius: 8px;
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
    background: var(--color-primary-50);
}

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

.menu-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-dark);
    border-radius: 2px;
    transition: var(--transition);
}

.menu-toggle.open span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle.open span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.open span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ========================================
   Hero
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 120px 24px 80px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.hero-gradient {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 30%, #1e40af 60%, #2563eb 100%);
}

.hero-pattern {
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 20% 50%, rgba(37, 99, 235, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(14, 165, 233, 0.2) 0%, transparent 40%),
        radial-gradient(circle at 60% 80%, rgba(16, 185, 129, 0.15) 0%, transparent 40%);
}

.hero-pattern::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
}

.hero-badge {
    display: inline-block;
    padding: 8px 20px;
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.15);
    border-radius: 50px;
    color: rgba(255,255,255,0.8);
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 32px;
    backdrop-filter: blur(10px);
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 900;
    line-height: 1.15;
    color: #fff;
    margin-bottom: 24px;
}

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

.hero-title-line.accent {
    background: linear-gradient(135deg, #60a5fa, #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.15rem;
    color: rgba(255,255,255,0.7);
    margin-bottom: 40px;
    letter-spacing: 0.08em;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 64px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: 10px;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-family);
}

.btn-primary {
    background: var(--color-primary);
    color: #fff;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
    background: #1d4ed8;
    box-shadow: 0 6px 25px rgba(37, 99, 235, 0.45);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: #fff;
    border: 1.5px solid rgba(255,255,255,0.3);
}

.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: rgba(255,255,255,0.5);
}

.btn-lg {
    padding: 18px 40px;
    font-size: 1.05rem;
}

.btn-full {
    width: 100%;
    justify-content: center;
}

/* Hero Stats */
.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    padding-top: 48px;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.stat {
    text-align: center;
}

.stat-num {
    font-size: 2rem;
    font-weight: 800;
    color: #fff;
    line-height: 1;
}

.stat-suffix {
    font-size: 1.5rem;
    font-weight: 700;
    color: #60a5fa;
}

.stat-label {
    display: block;
    font-size: 0.8rem;
    color: rgba(255,255,255,0.5);
    margin-top: 8px;
}

/* Hero Scroll Indicator */
.hero-scroll {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: rgba(255,255,255,0.4);
    font-size: 0.75rem;
    letter-spacing: 0.1em;
}

.scroll-indicator {
    width: 2px;
    height: 40px;
    background: rgba(255,255,255,0.15);
    border-radius: 2px;
    position: relative;
    overflow: hidden;
}

.scroll-indicator::after {
    content: '';
    position: absolute;
    top: -100%;
    left: 0;
    width: 100%;
    height: 50%;
    background: rgba(255,255,255,0.6);
    border-radius: 2px;
    animation: scrollDown 2s infinite;
}

@keyframes scrollDown {
    0% { top: -50%; }
    100% { top: 100%; }
}

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

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

.section-tag {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.15em;
    margin-bottom: 12px;
}

.section-title {
    font-size: clamp(1.8rem, 3vw, 2.5rem);
    font-weight: 800;
    color: var(--color-dark);
    margin-bottom: 16px;
    line-height: 1.3;
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--color-text-light);
    max-width: 600px;
    margin: 0 auto;
}

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

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.about-image {
    position: relative;
}

.about-img-wrapper {
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.about-img-placeholder {
    background: linear-gradient(135deg, #e0e7ff, #dbeafe);
    aspect-ratio: 4/3;
    display: flex;
    align-items: center;
    justify-content: center;
}

.about-img-placeholder svg {
    width: 100%;
    height: 100%;
}

.about-float-card {
    position: absolute;
    bottom: -20px;
    right: -20px;
    background: #fff;
    padding: 16px 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 12px;
}

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

.about-float-card strong {
    display: block;
    font-size: 0.9rem;
    color: var(--color-dark);
}

.about-float-card span {
    font-size: 0.8rem;
    color: var(--color-text-light);
}

.about-content h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 20px;
}

.about-content p {
    margin-bottom: 16px;
    color: var(--color-text-light);
    line-height: 1.8;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: 24px;
}

.about-feature {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-dark);
}

.feature-check {
    width: 28px;
    height: 28px;
    background: var(--color-primary-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
    flex-shrink: 0;
}

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

.service-card {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition);
}

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

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

.service-icon {
    width: 56px;
    height: 56px;
    background: var(--color-primary-50);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
    margin-bottom: 20px;
    transition: var(--transition);
}

.service-card:hover .service-icon {
    background: var(--color-primary);
    color: #fff;
}

.service-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 12px;
}

.service-card p {
    font-size: 0.9rem;
    color: var(--color-text-light);
    line-height: 1.7;
    margin-bottom: 20px;
}

.service-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-primary);
}

.service-link:hover {
    gap: 10px;
}

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

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

.advantage-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 40px 32px;
    transition: var(--transition);
    border: 1px solid var(--color-border);
}

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

.advantage-number {
    font-size: 2.5rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin-bottom: 20px;
}

.advantage-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 12px;
}

.advantage-card p {
    font-size: 0.9rem;
    color: var(--color-text-light);
    line-height: 1.7;
}

/* ========================================
   Cases Section
   ======================================== */
.cases-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto auto;
    gap: 24px;
}

.case-card {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    min-height: 280px;
    cursor: pointer;
    transition: var(--transition);
}

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

.case-large {
    grid-row: span 2;
    min-height: 580px;
}

.case-bg {
    position: absolute;
    inset: 0;
}

.case-content {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 32px;
    background: linear-gradient(transparent, rgba(0,0,0,0.6));
    color: #fff;
}

.case-tag {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(255,255,255,0.2);
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
    margin-bottom: 12px;
    backdrop-filter: blur(4px);
}

.case-content h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.case-content p {
    font-size: 0.85rem;
    color: rgba(255,255,255,0.8);
    line-height: 1.6;
}

/* ========================================
   CTA Section
   ======================================== */
.cta {
    padding: 60px 0;
}

.cta-card {
    background: linear-gradient(135deg, #1e3a5f, #2563eb);
    border-radius: var(--radius-lg);
    padding: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 40px;
    position: relative;
    overflow: hidden;
}

.cta-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(255,255,255,0.1), transparent 70%);
    border-radius: 50%;
}

.cta-content {
    position: relative;
}

.cta-content h2 {
    font-size: 1.8rem;
    font-weight: 800;
    color: #fff;
    margin-bottom: 8px;
}

.cta-content p {
    color: rgba(255,255,255,0.7);
    font-size: 1rem;
}

.cta .btn-primary {
    flex-shrink: 0;
    position: relative;
    background: #fff;
    color: var(--color-primary);
    box-shadow: 0 4px 15px rgba(0,0,0,0.15);
}

.cta .btn-primary:hover {
    background: #f0f4ff;
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(0,0,0,0.2);
}

/* ========================================
   Contact Section
   ======================================== */
.contact {
    background: var(--color-bg-alt);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 64px;
    align-items: start;
}

.contact-item {
    display: flex;
    gap: 16px;
    padding: 20px 0;
    border-bottom: 1px solid var(--color-border);
}

.contact-item:last-child {
    border-bottom: none;
}

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

.contact-item h4 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-dark);
    margin-bottom: 4px;
}

.contact-item p {
    font-size: 0.9rem;
    color: var(--color-text-light);
}

.contact-form-wrapper {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow-md);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

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

.contact-form input,
.contact-form select,
.contact-form textarea {
    width: 100%;
    padding: 14px 18px;
    font-size: 0.9rem;
    font-family: var(--font-family);
    border: 1.5px solid var(--color-border);
    border-radius: 10px;
    background: var(--color-bg-alt);
    color: var(--color-text);
    transition: var(--transition);
    outline: none;
}

.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
    border-color: var(--color-primary);
    background: #fff;
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

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

.contact-form select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%2364748b' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    padding-right: 40px;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: var(--color-dark);
    color: rgba(255,255,255,0.6);
    padding: 64px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 48px;
    padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
}

.footer-logo .logo-icon {
    width: 36px;
    height: 36px;
}

.footer-desc {
    font-size: 0.85rem;
    line-height: 1.8;
}

.footer-links h4 {
    color: #fff;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.footer-links a {
    display: block;
    font-size: 0.85rem;
    padding: 6px 0;
    color: rgba(255,255,255,0.5);
}

.footer-links a:hover {
    color: #fff;
    padding-left: 4px;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 0;
    font-size: 0.8rem;
}

.footer-bottom a {
    color: rgba(255,255,255,0.4);
}

.footer-bottom a:hover {
    color: #fff;
}

/* ========================================
   Back to Top
   ======================================== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: #fff;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.35);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    z-index: 999;
}

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

.back-to-top:hover {
    background: #1d4ed8;
    transform: translateY(-3px);
    box-shadow: 0 6px 25px rgba(37, 99, 235, 0.45);
}

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

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

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

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

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }

    .cta-card {
        flex-direction: column;
        text-align: center;
        padding: 48px 32px;
    }
}

@media (max-width: 768px) {
    .nav {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 16px;
        gap: 4px;
        border-bottom: 1px solid var(--color-border);
        transform: translateY(-120%);
        transition: var(--transition);
        box-shadow: var(--shadow-lg);
    }

    .nav.open {
        transform: translateY(0);
    }

    .menu-toggle {
        display: flex;
    }

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

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

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

    .case-large {
        grid-row: span 1;
        min-height: 300px;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }

    .hero-title {
        font-size: 2.2rem;
    }

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

    .about-float-card {
        right: 10px;
        bottom: -10px;
    }

    .section {
        padding: 64px 0;
    }
}

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

    .stat-num {
        font-size: 1.5rem;
    }

    .contact-form-wrapper {
        padding: 24px;
    }
}