/* CSS变量定义 */
:root {
    /* 颜色系统 */
    --color-background: #0f172a;
    --color-text-primary: #ffffff;
    --color-text-secondary: #94a3b8;

    /* 玻璃拟态 Colors */
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-bg-hover: rgba(255, 255, 255, 0.1);
    --glass-border-hover: rgba(255, 255, 255, 0.2);

    /* System Gradients */
    --gradient-csim: linear-gradient(135deg, #2dd4bf 0%, #0d9488 100%);
    --gradient-cts: linear-gradient(135deg, #a78bfa 0%, #7c3aed 100%);
    --gradient-sales: linear-gradient(135deg, #60a5fa 0%, #3b82f6 100%);

    --color-csim: #2dd4bf;
    --color-cts: #a78bfa;
    --color-sales: #60a5fa;

    /* 间距系统 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* 圆角 */
    --radius-lg: 0.75rem;
    --radius-xl: 1.25rem;

    /* 动画 */
    --duration-normal: 300ms;
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--color-background);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
}

/* 容器与布局 */
.container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    position: relative;
    overflow: hidden;
}

/* 背景装饰 (Orbs) */
.background-decoration {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
}

.bg-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    animation: float 20s ease-in-out infinite;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: #3b82f6;
    top: -100px;
    left: -100px;
    animation-delay: 0s;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: #8b5cf6;
    bottom: -50px;
    right: -50px;
    animation-delay: -5s;
}

.orb-3 {
    width: 300px;
    height: 300px;
    background: #2dd4bf;
    bottom: 20%;
    left: 20%;
    opacity: 0.2;
    animation-delay: -10s;
}

@keyframes float {

    0%,
    100% {
        transform: translate(0, 0);
    }

    33% {
        transform: translate(30px, -50px);
    }

    66% {
        transform: translate(-20px, 20px);
    }
}

/* 主要内容 */
.main-content {
    position: relative;
    z-index: 1;
    text-align: center;
    width: 100%;
    max-width: 1200px;
}

/* 头部 */
.header {
    margin-bottom: var(--spacing-2xl);
    animation: fadeInUp 1s ease-out 0.2s forwards;
    opacity: 0;
    transform: translateY(-20px);
}

.title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 300;
    color: #fff;
    margin-bottom: var(--spacing-sm);
    letter-spacing: 2px;
}

.subtitle {
    font-size: clamp(1rem, 2.5vw, 1.1rem);
    color: var(--color-text-secondary);
    font-weight: 300;
    letter-spacing: 0.5px;
}

/* 导航网格 */
.navigation-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    justify-content: center;
}

/* 导航卡片 (Glass Style) */
.nav-card {
    display: block;
    text-decoration: none;
    position: relative;
    padding: var(--spacing-xl);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    transition: all var(--duration-normal) cubic-bezier(0.4, 0, 0.2, 1);
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 1s ease-out forwards;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.nav-card:hover {
    transform: translateY(-10px);
    background: var(--glass-bg-hover);
    border-color: var(--glass-border-hover);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.nav-card:nth-child(1) {
    animation-delay: 0.4s;
}

.nav-card:nth-child(2) {
    animation-delay: 0.6s;
}

.nav-card:nth-child(3) {
    animation-delay: 0.8s;
}

/* 卡片内容 */
.card-content {
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.card-icon {
    width: 64px;
    height: 64px;
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-lg);
    color: white;
    transition: transform var(--duration-normal) ease;
}

.nav-card:hover .card-icon {
    transform: scale(1.1) rotate(5deg);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    transition: color var(--duration-normal) ease;
}

.card-description {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.card-url {
    font-size: 0.875rem;
    font-weight: 500;
    opacity: 0.8;
    margin-top: auto;
}

/* Specific Card Theming */
.csim-card .card-icon {
    background: var(--gradient-csim);
}

.csim-card .card-title {
    color: #fff;
}

.csim-card .card-url {
    color: var(--color-csim);
}

.csim-card:hover .card-title {
    color: var(--color-csim);
}

.cts-card .card-icon {
    background: var(--gradient-cts);
}

.cts-card .card-title {
    color: #fff;
}

.cts-card .card-url {
    color: var(--color-cts);
}

.cts-card:hover .card-title {
    color: var(--color-cts);
}

.sales-card .card-icon {
    background: var(--gradient-sales);
}

.sales-card .card-title {
    color: #fff;
}

.sales-card .card-url {
    color: var(--color-sales);
}

.sales-card:hover .card-title {
    color: var(--color-sales);
}

/* Card Arrow (Hidden/Subtle in this design, or we can remove it. Keeping for utility) */
.card-arrow {
    display: none;
    /* Removing as per concept minimal look */
}

/* Animations */
@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Ripple Element */
.card-ripple {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    opacity: 0;
    transform: scale(0);
    transition: all 0.5s ease;
}

.nav-card:active .card-ripple {
    opacity: 1;
    transform: scale(1);
    transition: 0s;
}

/* Responsive */
@media (max-width: 768px) {
    .navigation-grid {
        grid-template-columns: 1fr;
    }

    .orb-1,
    .orb-2,
    .orb-3 {
        opacity: 0.2;
    }
}