/* Fluent-inspired UI */
:root {
    --primary-color: #0b5cab;
    --primary-hover: #094a8a;
    --secondary-color: #d6d7df;
    --secondary-hover: #cbccd6;
    --text-primary: #1b1a19;
    --text-secondary: #3f3f3f;
    --bg-main: #ececf1;
    --bg-light: #e2e3ea;
    --border-color: #c7c8d2;
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.07);
    --shadow-md: 0 8px 18px rgba(0,0,0,0.14);
    --shadow-lg: 0 18px 40px rgba(0,0,0,0.20);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', 'Microsoft YaHei', 'PingFang SC', sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-main);
    line-height: 1.6;
    overflow-x: hidden;
}

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

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

/* Typography */
h1, h2, h3, h4 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 16px;
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 8px;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 48px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 10px 24px;
    border-radius: 4px; /* Slight rounded corners like modern Windows */
    font-weight: 600;
    cursor: pointer;
    border: 2px solid transparent;
    transition: var(--transition);
    text-align: center;
}

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

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

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

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

.btn-large {
    padding: 14px 32px;
    font-size: 1.1rem;
}

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

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

.link-action {
    display: inline-flex;
    align-items: center;
    font-weight: 600;
    margin-top: 16px;
}

.link-action i {
    margin-left: 8px;
    transition: transform 0.2s;
}

.link-action:hover i {
    transform: translateX(4px);
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(236, 236, 241, 0.92);
    backdrop-filter: blur(8px);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo-icon {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2px;
    width: 24px;
    height: 24px;
    margin-right: 12px;
}

.logo-icon .square {
    width: 100%;
    height: 100%;
    border-radius: 3px;
}
.logo-icon .c1 { background-color: #2563eb; }
.logo-icon .c2 { background-color: #7c3aed; }
.logo-icon .c3 { background-color: #06b6d4; }
.logo-icon .c4 { background-color: #f97316; }

.logo-icon.small { width: 16px; height: 16px; }

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-primary);
    font-weight: 500;
    position: relative;
    padding-bottom: 4px;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--primary-color);
    transition: width 0.3s;
}

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

/* Hero Section */
.hero {
    padding: 160px 0 100px;
    background: linear-gradient(135deg, #d6d7df 0%, #ececf1 100%);
}

.hero-content {
    display: flex;
    align-items: center;
    gap: 60px;
}

.hero-text {
    flex: 1;
}

.hero-text h1 {
    font-size: 3.5rem;
    color: var(--text-primary);
    margin-bottom: 24px;
}

.hero-text p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
}

.hero-image {
    flex: 1;
}

.hero-image img {
    width: 100%;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    transition: transform 0.5s ease;
}

.hero-image:hover img {
    transform: scale(1.02);
}

/* Sections & Grid */
.section {
    padding: 100px 0;
}

.bg-light {
    background-color: var(--bg-light);
}

.grid {
    display: grid;
    gap: 32px;
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

/* Cards */
.card {
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 32px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 24px;
}

.card-img {
    width: calc(100% + 64px);
    margin: -32px -32px 24px -32px;
    height: 200px;
    object-fit: cover;
    display: block;
    transition: transform 0.5s ease;
}

.card-body {
    position: relative;
    z-index: 1;
}

.highlight-card {
    border-top: 4px solid var(--primary-color);
}

/* Hover Effects */
.hover-up:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.hover-zoom:hover {
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

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

.hover-glow:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 34px rgba(11, 92, 171, 0.20);
}

/* Footer */
.footer {
    background-color: var(--secondary-color);
    padding: 60px 0 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-col h4 {
    margin-bottom: 24px;
    font-size: 1.1rem;
}

.footer-col a {
    display: block;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

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

.footer-col p {
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.footer-bottom {
    background-color: #cbccd6;
    padding: 24px 0;
    text-align: center;
    color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 992px) {
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
    .hero-content { flex-direction: column; text-align: center; }
    .hero-buttons { justify-content: center; }
    .nav-links { display: none; } /* Simple mobile fix */
}

@media (max-width: 768px) {
    .grid-3 { grid-template-columns: 1fr; }
    .footer-content { grid-template-columns: 1fr; }
    .hero-text h1 { font-size: 2.5rem; }
}