/* ========================================
   异环助手官网 - 现代化样式 v2
   ======================================== */

/* CSS 变量 */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #ec4899;
    --accent: #f59e0b;
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --bg-card-hover: #273549;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border: rgba(255, 255, 255, 0.08);
    --gradient: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 20px 40px -10px rgba(0, 0, 0, 0.3);
    --radius: 12px;
    --radius-lg: 20px;
}

/* 重置样式 */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    color: inherit;
    text-decoration: none;
}

ul {
    list-style: none;
}

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

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

/* ========================================
   头部导航
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.25rem;
    font-weight: 700;
}

.logo-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 40px;
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.9375rem;
    transition: color 0.3s;
}

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s;
}

/* ========================================
   Hero 区域
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse 100% 60% at 30% 20%, rgba(99, 102, 241, 0.2), transparent),
        radial-gradient(ellipse 80% 50% at 80% 60%, rgba(236, 72, 153, 0.15), transparent);
    z-index: 0;
}

.hero-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 30%, rgba(236, 72, 153, 0.1) 0%, transparent 50%);
}

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

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.hero-text {
    max-width: 520px;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(99, 102, 241, 0.12);
    border: 1px solid rgba(99, 102, 241, 0.25);
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--primary-light);
    margin-bottom: 24px;
}

.badge-dot {
    width: 6px;
    height: 6px;
    background: #10b981;
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(1.2); }
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 3.75rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 20px;
}

.gradient-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 24px;
}

.hero-hint {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* 合作伙伴链接 */
.hero-partner {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 24px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.partner-label {
    font-size: 0.8125rem;
    color: var(--text-muted);
    white-space: nowrap;
}

.partner-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid rgba(245, 158, 11, 0.25);
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 500;
    color: #f59e0b;
    transition: all 0.3s ease;
}

.partner-link:hover {
    background: rgba(245, 158, 11, 0.2);
    border-color: rgba(245, 158, 11, 0.4);
    transform: translateY(-2px);
}

.partner-link svg {
    fill: #f59e0b;
    stroke: none;
}

/* Hero 图片 */
.hero-image {
    position: relative;
}

.hero-image img {
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg), 0 0 0 1px rgba(255,255,255,0.1);
    transform: perspective(1000px) rotateY(-5deg) rotateX(5deg);
    transition: transform 0.5s ease;
}

.hero-image:hover img {
    transform: perspective(1000px) rotateY(0) rotateX(0);
}

.hero-image::before {
    content: '';
    position: absolute;
    inset: -2px;
    background: var(--gradient);
    border-radius: var(--radius-lg);
    z-index: -1;
    opacity: 0.5;
    filter: blur(20px);
}

/* 按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius);
    border: none;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn-primary {
    background: var(--gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.06);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.15);
}

/* ========================================
   功能区域
   ======================================== */
.features {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: rgba(99, 102, 241, 0.4);
    box-shadow: 0 20px 40px rgba(99, 102, 241, 0.15);
}

.feature-icon {
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.7;
    margin-bottom: 16px;
}

.feature-tag {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(99, 102, 241, 0.12);
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--primary-light);
}

/* ========================================
   下载区域
   ======================================== */
.download {
    padding: 100px 0;
    background: linear-gradient(180deg, transparent 0%, rgba(99, 102, 241, 0.03) 50%, transparent 100%);
}

.download-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 48px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    align-items: center;
}

.download-info h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 24px;
}

.download-features {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.download-features li {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-secondary);
    font-size: 1rem;
}

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

.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 18px 36px;
    background: var(--gradient);
    color: white;
    font-size: 1.125rem;
    font-weight: 600;
    border-radius: var(--radius);
    border: none;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

.btn-download:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.5);
}

.download-note {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-top: 16px;
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* ========================================
   FAQ 区域
   ======================================== */
.faq {
    padding: 100px 0;
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: border-color 0.3s;
}

.faq-item:hover {
    border-color: rgba(99, 102, 241, 0.3);
}

.faq-item summary {
    padding: 20px 24px;
    font-weight: 600;
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.3s;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: '+';
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--text-muted);
    transition: transform 0.3s;
}

.faq-item[open] summary::after {
    transform: rotate(45deg);
}

.faq-item[open] summary {
    border-bottom: 1px solid var(--border);
}

.faq-item p {
    padding: 20px 24px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========================================
   页脚
   ======================================== */
.footer {
    padding: 60px 0 30px;
    border-top: 1px solid var(--border);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.footer-brand-name {
    font-size: 1.25rem;
    font-weight: 700;
    margin-top: 8px;
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 0.9375rem;
}

.footer-links {
    display: flex;
    gap: 60px;
}

.footer-column {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-column h4 {
    font-weight: 600;
    margin-bottom: 4px;
}

.footer-column span,
.footer-column a {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    transition: color 0.3s;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid var(--border);
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 1024px) {
    .hero-grid {
        grid-template-columns: 1fr;
        gap: 48px;
        text-align: center;
    }
    
    .hero-text {
        max-width: 100%;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .hero-image {
        max-width: 600px;
        margin: 0 auto;
    }
    
    .hero-image img {
        transform: none;
    }
    
    .download-card {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .download-features li {
        justify-content: center;
    }
    
    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .section-header h2 {
        font-size: 2rem;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 30px;
    }
    
    .download-card {
        padding: 32px 24px;
    }
}

/* 滚动条 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-dark);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.15);
}