:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --secondary: #0f172a;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --bg-body: #f8fafc;
    --bg-white: #ffffff;
    --gradient-hero: linear-gradient(135deg, #eff6ff 0%, #ffffff 100%);
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-lg: 1rem;
    --radius-md: 0.75rem;
    --container-width: 1280px;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    color: var(--text-main);
    background-color: var(--bg-body);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s;
}

ul {
    list-style: none;
}

/* Layout Utilities */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 5rem 0;
    overflow: hidden;
}

.grid {
    display: grid;
    gap: 2rem;
}

.flex {
    display: flex;
}

.items-center {
    align-items: center;
}

.justify-between {
    justify-content: space-between;
}

.justify-center {
    justify-content: center;
}

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

.p-0 {
    padding: 0 !important;
}

/* Typography */
h1, h2, h3, h4 {
    color: var(--secondary);
    font-weight: 700;
    line-height: 1.2;
}

h1 {
    font-size: 3.5rem;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.text-lead {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 1rem auto 2rem;
}

.section-header {
    margin-bottom: 4rem;
    text-align: center;
}

.section-header h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--primary);
    margin: 1rem auto 0;
    border-radius: 2px;
}

/* Header / Nav */
.site-header {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(0,0,0,0.05);
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo img {
    height: 40px;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 800;
    line-height: 1;
    white-space: nowrap;
    background: linear-gradient(to right, var(--secondary), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    font-weight: 500;
    color: var(--text-main);
}

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

/* Hero Section */
.hero {
    min-height: 90vh;
    display: flex;
    align-items: center;
    background: var(--gradient-hero);
    position: relative;
    padding-top: 4rem;
}

.hero-content {
    display: flex;
    justify-content: center;
    align-items: center;
    max-width: 900px;
    margin: 0 auto;
}

.hero-text {
    width: 100%;
    margin: 0 auto;
}

.hero-text h1 {
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, var(--secondary), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-text .desc {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 2.5rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    padding: 0.875rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 4px 14px 0 rgba(37, 99, 235, 0.39);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px 0 rgba(37, 99, 235, 0.23);
}

.hero-image {
    position: relative;
    animation: float 6s ease-in-out infinite;
}

.hero-image img {
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
    100% { transform: translateY(0px); }
}

/* Guardians Grid */
.guardians-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.guardian-card {
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: white;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease;
    padding: 1.5rem;
}

.guardian-card:hover {
    transform: translateY(-10px);
}

/* Services Grid */
.services-scroller {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2.5rem;
    padding-bottom: 2rem;
    width: 100%;
}

.service-card {
    border-radius: var(--radius-lg);
    overflow: hidden;
    position: relative;
    aspect-ratio: 3/4; /* Maintains portrait ratio for large clear images */
    box-shadow: var(--shadow-md);
    transition: transform 0.4s ease, box-shadow 0.4s ease;
}

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

.service-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

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

/* Tech Features (Redesigned) */
.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.tech-card {
    background: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
    height: 100%;
}

.tech-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.tech-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.tech-icon {
    width: 60px;
    height: 60px;
    flex-shrink: 0;
    background: #eff6ff;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 10px;
}

.tech-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.tech-card h3 {
    font-size: 1.5rem;
    color: var(--secondary);
    margin-bottom: 0;
}

.tech-body p {
    color: var(--text-muted);
    font-size: 1rem;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.tech-body p:last-child {
    margin-bottom: 0;
}

/* MultiGuard Features (Old - Kept for reference or if needed elsewhere, but mostly replaced by tech-grid) */
.feature-block {
    display: flex;
    align-items: center;
    gap: 4rem;
    margin-bottom: 6rem;
}

.feature-block:nth-child(even) {
    flex-direction: row-reverse;
}

.feature-image {
    flex: 1;
}

.feature-image img {
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.feature-content {
    flex: 1;
}

.feature-content h3 {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
}

.feature-content p {
    margin-bottom: 1rem;
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Core Advantages */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.advantage-card {
    background: white;
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
}

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

.advantage-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.advantage-icon {
    width: 32px;
    height: 32px;
    min-width: 32px;
    background: #eff6ff;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
}

.advantage-icon svg {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

.advantage-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0;
}

.advantage-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Partners */
.partners-scroll {
    overflow: hidden;
    white-space: nowrap;
    padding: 2rem 0;
    position: relative;
}

.partners-track {
    display: inline-flex;
    gap: 3rem;
    animation: scroll 80s linear infinite;
}

.partner-logo {
    height: 120px;
    opacity: 1 !important;
    transition: transform 0.3s ease;
    filter: grayscale(0) !important;
    -webkit-filter: grayscale(0) !important; /* 兼容性 */
}

.partner-logo:hover {
    transform: scale(1.05);
    opacity: 1 !important;
    filter: none !important;
}

@keyframes scroll {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

/* CTA Footer */
.cta-section {
    background: var(--secondary);
    color: white;
    text-align: center;
    position: relative;
    padding: 8rem 0;
}

.cta-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.1;
}

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

.cta-content h2 {
    color: white;
    margin-bottom: 1rem;
}

.cta-content p {
    color: #94a3b8;
    font-size: 1.5rem;
}

/* Footer */
.site-footer {
    background: #0b1120;
    color: #cbd5e1;
    padding: 4rem 0 2rem;
    font-size: 0.9rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-col h4 {
    color: white;
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.footer-info p {
    margin-bottom: 0.75rem;
}

.footer-qr {
    display: flex;
    gap: 1.5rem;
}

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

.qr-item img {
    width: 100px;
    height: 100px;
    border-radius: 8px;
    margin-bottom: 0.5rem;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 2rem;
    text-align: center;
    color: #64748b;
}

/* Responsive */
@media (max-width: 992px) {
    h1 { font-size: 2.5rem; }
    .hero-content { grid-template-columns: 1fr; text-align: center; }
    .hero-image { order: -1; max-width: 500px; margin: 0 auto; }
    .feature-block, .feature-block:nth-child(even) { flex-direction: column; text-align: center; }
}

@media (max-width: 768px) {
    .container { padding: 0 1.5rem; }
    .nav-links { display: none; } /* Simplified for mobile */
    .hero { padding-top: 2rem; }
}