/* ============================================
   青澜集团官网 - Awwwards级重构
   Qinglan Group - Award-Winning Design
   ============================================ */

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

:root {
    /* 色彩系统 - 深炭黑+暖金 */
    --bg-primary: #0c0c0c;
    --bg-secondary: #141414;
    --bg-tertiary: #1a1a1a;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --accent-gold: #c9a962;
    --accent-gold-light: #d4b978;
    --accent-gold-dark: #a88b4a;
    
    /* 间距系统 */
    --space-xs: 1rem;
    --space-sm: 2rem;
    --space-md: 4rem;
    --space-lg: 6rem;
    --space-xl: 10rem;
    
    /* 字体 */
    --font-display: 'Cormorant Garamond', 'Noto Serif SC', Georgia, serif;
    --font-body: 'Source Sans 3', 'Noto Sans SC', -apple-system, sans-serif;
    --font-mono: 'SF Mono', Monaco, monospace;
    
    /* 动画 */
    --ease-smooth: cubic-bezier(0.4, 0, 0.2, 1);
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-spring: cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    overflow-x: hidden;
}

/* Selection */
::selection {
    background: var(--accent-gold);
    color: var(--bg-primary);
}

/* ============================================
   Preloader
   ============================================ */
.preloader {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.8s var(--ease-out-expo), visibility 0.8s;
}

.preloader.loaded {
    opacity: 0;
    visibility: hidden;
}

.preloader-text {
    font-family: var(--font-display);
    font-size: clamp(2rem, 5vw, 4rem);
    font-weight: 300;
    letter-spacing: 0.2em;
}

.preloader-text span {
    display: inline-block;
    opacity: 0;
    transform: translateY(20px);
    animation: preloader-reveal 0.6s var(--ease-out-expo) forwards;
}

.preloader-text span:nth-child(1) { animation-delay: 0.1s; }
.preloader-text span:nth-child(2) { animation-delay: 0.2s; }
.preloader-text span:nth-child(3) { animation-delay: 0.3s; }
.preloader-text span:nth-child(4) { animation-delay: 0.4s; }

@keyframes preloader-reveal {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================
   Navigation
   ============================================ */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1.5rem 3rem;
    transition: all 0.4s var(--ease-smooth);
}

.nav.scrolled {
    background: rgba(12, 12, 12, 0.9);
    backdrop-filter: blur(20px);
    padding: 1rem 3rem;
}

.nav-container {
    max-width: 1600px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: 0.02em;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 3rem;
    list-style: none;
}

.nav-link {
    font-size: 0.875rem;
    font-weight: 400;
    color: var(--text-secondary);
    text-decoration: none;
    letter-spacing: 0.05em;
    position: relative;
    transition: color 0.3s;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent-gold);
    transition: width 0.4s var(--ease-out-expo);
}

.nav-link:hover {
    color: var(--text-primary);
}

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

.nav-cta {
    padding: 0.75rem 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.4s;
}

.nav-cta:hover {
    background: var(--accent-gold);
    border-color: var(--accent-gold);
    color: var(--bg-primary);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 8rem 3rem;
    position: relative;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse at 20% 50%, rgba(201, 169, 98, 0.03) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(201, 169, 98, 0.02) 0%, transparent 40%),
        var(--bg-primary);
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 1000px;
    text-align: center;
}

.hero-eyebrow {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 400;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--accent-gold);
    margin-bottom: 2rem;
    opacity: 0;
    transform: translateY(20px);
    animation: fade-up 0.8s var(--ease-out-expo) 0.5s forwards;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(3rem, 8vw, 7rem);
    font-weight: 300;
    line-height: 1.05;
    letter-spacing: -0.02em;
    margin-bottom: 2rem;
}

.hero-title-line {
    display: block;
    opacity: 0;
    transform: translateY(40px);
    animation: fade-up 1s var(--ease-out-expo) forwards;
}

.hero-title-line:nth-child(1) { animation-delay: 0.7s; }
.hero-title-line:nth-child(2) { animation-delay: 0.9s; }

@keyframes fade-up {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-title-accent {
    font-style: italic;
    color: var(--accent-gold);
}

.hero-subtitle {
    font-size: 1.125rem;
    font-weight: 300;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 3rem;
    line-height: 1.8;
    opacity: 0;
    animation: fade-up 1s var(--ease-out-expo) 1.1s forwards;
}

.hero-cta-group {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    opacity: 0;
    animation: fade-up 1s var(--ease-out-expo) 1.3s forwards;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 2rem;
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    text-decoration: none;
    transition: all 0.4s var(--ease-smooth);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--accent-gold);
    color: var(--bg-primary);
}

.btn-primary:hover {
    background: var(--accent-gold-light);
    transform: translateY(-2px);
    box-shadow: 0 10px 40px rgba(201, 169, 98, 0.2);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.4);
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 3rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    opacity: 0;
    animation: fade-in 1s var(--ease-out-expo) 1.5s forwards;
}

@keyframes fade-in {
    to { opacity: 1; }
}

.scroll-text {
    font-family: var(--font-mono);
    font-size: 0.625rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--text-muted);
}

.scroll-line {
    width: 1px;
    height: 60px;
    background: linear-gradient(to bottom, var(--accent-gold), transparent);
    animation: scroll-pulse 2s ease-in-out infinite;
}

@keyframes scroll-pulse {
    0%, 100% { opacity: 0.3; transform: scaleY(1); }
    50% { opacity: 0.6; transform: scaleY(0.7); }
}

/* ============================================
   Section Common
   ============================================ */
.section {
    padding: var(--space-xl) 3rem;
    position: relative;
}

.section-container {
    max-width: 1400px;
    margin: 0 auto;
}

.section-header {
    margin-bottom: var(--space-lg);
}

.section-eyebrow {
    display: block;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 400;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    color: var(--accent-gold);
    margin-bottom: 1rem;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 300;
    line-height: 1.1;
}

.section-title em {
    font-style: italic;
    color: var(--accent-gold);
}

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

.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: var(--space-lg);
    align-items: center;
}

.about-content {
    max-width: 600px;
}

.about-lead {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 300;
    line-height: 1.5;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

.about-text {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.9;
    margin-bottom: 3rem;
}

.about-stats {
    display: flex;
    gap: 4rem;
}

.about-stat {
    position: relative;
}

.about-stat::after {
    content: '';
    position: absolute;
    right: -2rem;
    top: 50%;
    transform: translateY(-50%);
    width: 1px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
}

.about-stat:last-child::after {
    display: none;
}

.about-stat-value {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 300;
    color: var(--accent-gold);
    line-height: 1;
}

.about-stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
    letter-spacing: 0.05em;
}

/* ============================================
   Core Technology Section
   ============================================ */
.core-tech {
    text-align: center;
}

.core-visual {
    width: 280px;
    height: 280px;
    margin: 0 auto 4rem;
    position: relative;
}

.core-ring {
    position: absolute;
    inset: 0;
    border: 1px solid rgba(201, 169, 98, 0.15);
    border-radius: 50%;
    animation: rotate 30s linear infinite;
}

.core-ring:nth-child(2) {
    inset: 40px;
    border-color: rgba(201, 169, 98, 0.3);
    animation-duration: 20s;
    animation-direction: reverse;
}

.core-ring:nth-child(3) {
    inset: 80px;
    border-color: var(--accent-gold);
    animation-duration: 15s;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.core-dot {
    position: absolute;
    inset: 110px;
    background: var(--accent-gold);
    border-radius: 50%;
    box-shadow: 0 0 60px rgba(201, 169, 98, 0.3);
}

.core-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto 3rem;
    line-height: 1.9;
}

.core-features {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.core-feature {
    padding: 0.875rem 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.75rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-secondary);
}

/* ============================================
   Business Lines Section
   ============================================ */
.business {
    background: var(--bg-secondary);
}

.business-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1px;
    background: rgba(255, 255, 255, 0.05);
}

.business-card {
    background: var(--bg-secondary);
    padding: 4rem;
    position: relative;
    overflow: hidden;
    cursor: pointer;
    transition: background 0.4s;
}

.business-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--accent-gold);
    opacity: 0;
    transition: opacity 0.4s;
}

.business-card:hover {
    background: var(--bg-tertiary);
}

.business-card:hover::before {
    opacity: 0.02;
}

.business-card-num {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.15em;
    color: var(--accent-gold);
    margin-bottom: 1.5rem;
}

.business-card-title {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 400;
    color: var(--text-primary);
    margin-bottom: 1rem;
    transition: color 0.4s;
}

.business-card:hover .business-card-title {
    color: var(--accent-gold);
}

.business-card-desc {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 2rem;
}

.business-card-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.4s;
}

.business-card:hover .business-card-link {
    color: var(--accent-gold);
}

.business-card-link svg {
    width: 16px;
    height: 16px;
    transition: transform 0.4s var(--ease-out-expo);
}

.business-card:hover .business-card-link svg {
    transform: translateX(4px);
}

/* ============================================
   Process Section
   ============================================ */
.process {
    text-align: center;
}

.process-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    margin-top: 4rem;
}

.process-step {
    text-align: left;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: all 0.4s;
}

.process-step:hover {
    border-color: rgba(201, 169, 98, 0.2);
    background: rgba(201, 169, 98, 0.02);
}

.process-step-num {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 300;
    color: var(--accent-gold);
    opacity: 0.5;
    margin-bottom: 1rem;
}

.process-step-title {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.process-step-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   Testimonials Section
   ============================================ */
.testimonials {
    background: var(--bg-secondary);
}

.testimonial-slider {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.testimonial-quote {
    font-family: var(--font-display);
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 300;
    font-style: italic;
    line-height: 1.6;
    color: var(--text-primary);
    margin-bottom: 2rem;
}

.testimonial-author {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.testimonial-author strong {
    color: var(--accent-gold);
    font-weight: 500;
}

/* ============================================
   Contact Section
   ============================================ */
.contact {
    text-align: center;
    padding-bottom: var(--space-xl);
}

.contact-content {
    max-width: 600px;
    margin: 0 auto;
}

.contact-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 300;
    margin-bottom: 1rem;
}

.contact-text {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.contact-email {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--accent-gold);
    text-decoration: none;
    display: inline-block;
    margin-bottom: 2rem;
    transition: opacity 0.3s;
}

.contact-email:hover {
    opacity: 0.7;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: var(--bg-primary);
    padding: 3rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-logo {
    font-family: var(--font-display);
    font-size: 1.25rem;
    color: var(--text-primary);
    text-decoration: none;
}

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

.footer-link {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-decoration: none;
    letter-spacing: 0.05em;
    transition: color 0.3s;
}

.footer-link:hover {
    color: var(--text-primary);
}

.footer-copy {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 1024px) {
    .about-grid {
        grid-template-columns: 1fr;
    }
    
    .business-grid {
        grid-template-columns: 1fr;
    }
    
    .process-steps {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .business-card {
        padding: 3rem;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero-cta-group {
        flex-direction: column;
    }
    
    .process-steps {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        flex-direction: column;
        gap: 2rem;
    }
    
    .about-stat::after {
        display: none;
    }
    
    .footer-container {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
    }
    
    .section {
        padding: var(--space-lg) 1.5rem;
    }
}

/* ============================================
   AI Organization Section
   ============================================ */
.ai-org {
    background: var(--bg-secondary);
}

.ai-org-intro {
    max-width: 800px;
    margin: 0 auto var(--space-lg);
    text-align: center;
}

.ai-org-lead {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 300;
    line-height: 1.6;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

.ai-org-text {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.ai-org-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    margin-bottom: var(--space-lg);
    padding: 3rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.ai-org-stat {
    text-align: center;
}

.ai-org-stat-value {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 300;
    color: var(--accent-gold);
    line-height: 1;
    margin-bottom: 0.75rem;
}

.ai-org-stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.ai-org-departments {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: var(--space-lg);
}

.ai-org-dept {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.25rem 1.5rem;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: all 0.3s var(--ease-smooth);
}

.ai-org-dept:hover {
    background: rgba(201, 169, 98, 0.05);
    border-color: rgba(201, 169, 98, 0.2);
}

.ai-org-dept-num {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--accent-gold);
    opacity: 0.6;
}

.ai-org-dept-name {
    flex: 1;
    font-family: var(--font-body);
    font-size: 0.9375rem;
    font-weight: 400;
    color: var(--text-primary);
}

.ai-org-dept-count {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.ai-org-cta {
    text-align: center;
}

@media (max-width: 1024px) {
    .ai-org-departments {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .ai-org-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 2rem 1rem;
    }
    
    .ai-org-departments {
        grid-template-columns: 1fr;
    }
}