/* 
 * 淇逸科技 (Beijing) Co., Ltd. 
 * Global Design Tokens & Base Styles
 */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=Outfit:wght@600;700;800&display=swap');

:root {
    /* Color Palette - Scientific Tech Theme */
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: rgba(37, 99, 235, 0.1);
    --bg-deep: #F8FAFC; /* Light gray/blue tint for background */
    --bg-card: #FFFFFF;
    --bg-nav: rgba(255, 255, 255, 0.95);
    
    /* Text Colors */
    --text-main: #0F172A; /* Slate 900 */
    --text-muted: #334155; /* Slate 700 */
    --text-dark: #64748B;  /* Slate 500 */
    
    /* Effects & Glass */
    --glass-border: rgba(0, 0, 0, 0.06);
    --glass-shadow: 0 10px 30px rgba(0, 0, 0, 0.04);
    --accent-gradient: linear-gradient(135deg, #1e3a8a 0%, #3b82f6 100%);
    
    /* Layout - Expanded for a grander feel */
    --nav-height: 80px;
    --sidebar-width: 300px;
    --container-max: 1536px;
    --container-padding: 3rem;
}

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

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

body {
    background: var(--bg-deep);
    color: var(--text-main);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

main {
    flex: 1;
}

h1, h2, h3, h4, .font-heading {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-main);
}

a {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
    color: inherit;
}

p {
    margin-bottom: 1rem;
    color: var(--text-muted);
}

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

@media (max-width: 1024px) {
    .container {
        padding: 1.5rem 2rem;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 1rem 1.5rem;
    }
}

.glass {
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white !important;
    padding: 0.75rem 1.75rem;
    border-radius: 8px;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.2);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.35);
}

/* --- Main Layout Sections --- */
.site-header {
    height: var(--nav-height);
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--bg-nav);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--glass-border);
    display: flex;
    align-items: center;
}

.header-container {
    max-width: var(--container-max);
    width: 100%;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    flex-shrink: 0;
}

@media (max-width: 640px) {
    .logo-text {
        display: none;
    }
}

.logo-highlight {
    color: var(--text-main);
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
    list-style: none;
}

@media (max-width: 768px) {
    .nav-links {
        gap: 1.25rem;
    }
}

@media (max-width: 480px) {
    .nav-links {
        gap: 0.75rem;
    }
    .nav-item a {
        font-size: 0.85rem;
    }
}

.nav-item a {
    color: var(--text-main);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.5rem 0;
    position: relative;
    transition: color 0.3s ease;
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        height: calc(100vh - var(--nav-height));
        background: #FFFFFF;
        flex-direction: column;
        justify-content: flex-start !important;
        align-items: center !important;
        padding-top: 4rem;
        gap: 3rem;
        /* ✔ 用 transform 替代 right，不触发页面横向溢出 */
        transform: translateX(100%);
        visibility: hidden;
        pointer-events: none;
        transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), 
                    visibility 0.4s cubic-bezier(0.16, 1, 0.3, 1);
        z-index: 1000;
        overflow-y: auto;
        overflow-x: hidden;
        box-shadow: -4px 0 20px rgba(0,0,0,0.08);
    }
    
    .nav-links.active {
        transform: translateX(0);
        visibility: visible;
        pointer-events: auto;
    }

    .nav-item a {
        font-size: 1.25rem;
        font-weight: 600;
    }
}

/* Hamburger Toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1100;
}

.menu-toggle span {
    width: 100%;
    height: 2px;
    background-color: var(--text-main);
    transition: all 0.3s ease;
}

@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
        margin-left: auto;
    }
}

/* Toggle Animation */
.menu-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.menu-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

body.menu-open {
    overflow: hidden;
}

.nav-item a:hover, .nav-item a.active {
    color: var(--primary);
}

.nav-item a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0%;
    height: 2px;
    background: var(--primary);
    transition: width 0.3s ease;
}

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

.site-footer {
    padding: 4rem 2rem 2rem;
    border-top: 1px solid var(--glass-border);
    margin-top: 4rem;
    color: var(--text-muted);
    background: var(--bg-nav);
}

.footer-container {
    max-width: var(--container-max);
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 2rem;
    text-align: center;
}

/* --- Premium Animations & Effects --- */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes gradientFlow {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.animate-fade-in-up {
    animation: fadeInUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) backwards;
}

.delay-100 { animation-delay: 0.1s; }
.delay-200 { animation-delay: 0.2s; }
.delay-300 { animation-delay: 0.3s; }
.delay-400 { animation-delay: 0.4s; }

.glass-card {
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    box-shadow: var(--glass-shadow);
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    padding: 2.5rem;
}

.glass-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(15, 23, 42, 0.08); /* Dark slate shadow for scientific tech feel */
    border-color: rgba(37, 99, 235, 0.2); /* Subtle blue glow */
}

.text-gradient {
    background: transparent;
    color: #fff;
}

.primary-gradient-text {
    background: transparent;
    color: inherit;
}

/* Grid Layouts */
.grid-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2.5rem;
    margin-top: 2.5rem;
}

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

@media (max-width: 800px) {
    .featured-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .grid-cards {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

/* Responsive Banner Utilities */
.responsive-banner {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    align-items: center;
}

@media (max-width: 992px) {
    .responsive-banner {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 3rem 2rem !important;
        height: auto !important;
        min-height: 500px;
    }
    .responsive-banner > div {
        padding: 2rem 0;
    }
}

/* Responsive Footer */
.responsive-footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 4rem;
}

@media (max-width: 992px) {
    .responsive-footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 3rem;
    }
}

@media (max-width: 640px) {
    .responsive-footer-grid {
        grid-template-columns: 1fr;
        gap: 3rem;
        text-align: center !important;
    }
    .responsive-footer-grid > div {
        text-align: center !important;
    }
    .responsive-footer-grid h4 {
        margin-bottom: 1rem !important;
    }
    .responsive-footer-grid p {
        font-size: 0.9rem !important;
        max-width: 300px;
        margin-left: auto;
        margin-right: auto;
    }
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 6rem 1rem;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

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

/* Content Body (Markdown Generated) */
.content-body h2 {
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--glass-border);
}

.content-body h3 {
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.content-body ul, .content-body ol {
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
    color: var(--text-muted);
}

.content-body li {
    margin-bottom: 0.5rem;
}

.content-body table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 2rem;
    margin-bottom: 2rem;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    overflow: hidden;
}

.content-body th, .content-body td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--glass-border);
}

.content-body th {
    background: var(--bg-deep);
    font-weight: 600;
    color: var(--text-main);
}

/* --- Modern UI Sections (Grid v2 & Cards) --- */
.feature-grid-v2 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2.5rem;
    margin-top: 3rem;
}

.feature-card-v2 {
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 3rem 2rem;
    text-align: center;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 0 4px 20px rgba(15, 23, 42, 0.03);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.feature-card-v2:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(37, 99, 235, 0.08);
    border-color: rgba(37, 99, 235, 0.2);
}

.icon-wrapper {
    width: 64px;
    height: 64px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 2rem;
    transition: all 0.3s ease;
}

.feature-card-v2:hover .icon-wrapper {
    background: var(--primary);
    color: white;
    transform: scale(1.1);
}

.feature-card-v2 h3 {
    font-size: 1.25rem;
    margin-bottom: 1.25rem;
    color: var(--text-main);
}

.feature-card-v2 p {
    font-size: 0.95rem;
    line-height: 1.7;
    color: var(--text-muted);
    margin-bottom: 0;
}

.info-note {
    background: linear-gradient(135deg, #f8fafc 0%, #eff6ff 100%);
    border-left: 4px solid var(--primary);
    border-radius: 8px;
    padding: 2.5rem;
    margin: 3rem 0;
}

@media (max-width: 992px) {
    .feature-grid-v2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .feature-grid-v2 {
        grid-template-columns: 1fr;
    }
    .feature-card-v2 {
        padding: 2.5rem 1.5rem;
    }
}

/* Image Loading Effect */ img { transition: opacity 0.6s ease-out, filter 0.6s cubic-bezier(0.16, 1, 0.3, 1), transform 0.6s cubic-bezier(0.16, 1, 0.3, 1); } img.is-loading { opacity: 0; filter: blur(8px); transform: scale(0.98); } img.is-loaded { opacity: 1; filter: blur(0); transform: scale(1); }