/* 
 * 上海本达信息科技有限公司 - Main Stylesheet
 * Design: Techno-Futurist Minimal
 */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;600;800&family=Source+Sans+Pro:wght@400;600&display=swap');

:root {
    /* Color Palette - Midnight Immersive with Cyan */
    --color-bg: #0E0E12;
    --color-surface: #16161C;
    --color-surface-hover: #1F1F28;
    --color-text: #E8E6E1;
    --color-text-muted: #A0A0AA;
    --color-accent: #00E5FF;
    --color-accent-hover: #00B2CC;
    --color-border: rgba(255, 255, 255, 0.08);
    --color-shadow: rgba(0, 229, 255, 0.12);

    /* Spacing System */
    --space-sm: clamp(0.5rem, 1vw, 1rem);
    --space-md: clamp(1.5rem, 3vw, 2.5rem);
    --space-lg: clamp(4rem, 8vw, 8rem);
    --space-xl: clamp(8rem, 15vw, 16rem);

    /* Typography Scale */
    --font-display: 'Outfit', sans-serif;
    --font-body: 'Source Sans Pro', sans-serif;
}

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

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

body {
    background-color: var(--color-bg);
    color: var(--color-text);
    font-family: var(--font-body);
    line-height: 1.65;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* Texture Background */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3BaseFilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
    opacity: 0.03;
    pointer-events: none;
    z-index: 1000;
}

/* Typography */
h1, h2, h3, h4, .display-font {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.5rem, 6vw, 4.5rem); }
h2 { font-size: clamp(2rem, 5vw, 3.5rem); }
h3 { font-size: clamp(1.5rem, 4vw, 2.5rem); }

a {
    color: inherit;
    text-decoration: none;
    transition: all 0.3s ease;
}

ul { list-style: none; }

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5vw;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2.5rem;
    border-radius: 4px;
    font-family: var(--font-display);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    border: none;
    font-size: 1rem;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background-color: var(--color-accent);
    color: #000;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px var(--color-shadow);
    background-color: #fff;
}

.btn-secondary {
    background-color: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text);
}

.btn-secondary:hover {
    border-color: var(--color-accent);
    background-color: rgba(0, 229, 255, 0.05);
}

/* Header */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    padding: 1.5rem 0;
    transition: all 0.4s ease;
}

.site-header.scrolled {
    padding: 1rem 0;
    background: rgba(14, 14, 18, 0.85);
    backdrop-filter: blur(15px);
    border-bottom: 1px solid var(--color-border);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-display);
    font-weight: 800;
    font-size: 1.5rem;
    color: var(--color-text);
}

.logo span { color: var(--color-accent); }

.nav-links {
    display: flex;
    gap: 2.5rem;
}

.nav-links a {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 1rem;
    opacity: 0.7;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: width 0.3s ease;
}

.nav-links a:hover, .nav-links a.active {
    opacity: 1;
}

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

.mobile-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Footer */
.site-footer {
    padding: var(--space-lg) 0 var(--space-md);
    background-color: var(--color-surface);
    border-top: 1px solid var(--color-border);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 2fr;
    gap: 3rem;
    margin-bottom: var(--space-lg);
}

.footer-logo {
    margin-bottom: 1.5rem;
}

.footer-desc {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    max-width: 300px;
}

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

.footer-links li {
    margin-bottom: 0.8rem;
}

.footer-links a {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

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

.footer-contact p {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 0.5rem;
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid var(--color-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-bottom p, .footer-bottom a {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

/* Animations */
[data-animate] {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}

[data-animate].animate-in {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: fixed;
        top: 0;
        right: 0;
        height: 100vh;
        width: 70%;
        background: var(--color-surface);
        flex-direction: column;
        padding: 5rem 3rem;
        z-index: 99;
        box-shadow: -10px 0 30px rgba(0,0,0,0.5);
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-toggle {
        display: block;
        z-index: 101;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

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