/* CSS Variables */
:root {
    --primary: #00d4ff;
    --secondary: #0099cc;
    --accent: #00b3e6;
    --background: #1e293b;
    --foreground: #f8fafc;
    --card-bg: rgba(255, 255, 255, 0.12);
    --border: rgba(255, 255, 255, 0.2);
    --glass-bg: rgba(255, 255, 255, 0.18);
    --glass-border: rgba(255, 255, 255, 0.3);
}

/* Base Styles */
* {
    box-sizing: border-box;
}

body {
    background: var(--background);
    color: var(--foreground);
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    min-height: 100vh;
    line-height: 1.6;
    overflow-x: hidden;
    margin: 0;
    padding: 0;
}

/* Dynamic Background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(0, 212, 255, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(0, 153, 204, 0.2) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(0, 179, 230, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 60% 60%, rgba(0, 212, 255, 0.12) 0%, transparent 50%),
        radial-gradient(circle at 10% 10%, rgba(0, 153, 204, 0.18) 0%, transparent 50%);
    z-index: -3;
    animation: backgroundShift 25s ease-in-out infinite;
}

/* Grid Background */
body::after {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(0, 212, 255, 0.2) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 212, 255, 0.2) 1px, transparent 1px);
    background-size: 40px 40px;
    z-index: -2;
    animation: gridMove 20s linear infinite;
}

/* Animations */
@keyframes backgroundShift {
    0%, 100% { 
        opacity: 0.9;
        transform: scale(1) rotate(0deg);
    }
    25% { 
        opacity: 1;
        transform: scale(1.05) rotate(1deg);
    }
    50% { 
        opacity: 0.95;
        transform: scale(1.02) rotate(-0.5deg);
    }
    75% { 
        opacity: 1;
        transform: scale(1.03) rotate(0.5deg);
    }
}

@keyframes gridMove {
    0% { 
        transform: translate(0, 0) rotate(0deg);
        opacity: 0.8;
    }
    50% { 
        transform: translate(20px, 20px) rotate(0.5deg);
        opacity: 1;
    }
    100% { 
        transform: translate(40px, 40px) rotate(0deg);
        opacity: 0.8;
    }
}

/* Layout */
.container {
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 1rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.section {
    width: 100%;
    margin-bottom: 3rem;
}

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

/* Language Switcher */
.language-switcher {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    display: flex;
    gap: 10px;
}

.lang-btn {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 8px 16px;
    color: var(--foreground);
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 14px;
    font-weight: 500;
}

.lang-btn:hover {
    background: var(--glass-bg);
    border-color: var(--primary);
    transform: translateY(-1px);
}

.lang-btn.active {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--background);
    border-color: var(--primary);
}

/* Content Language Classes */
.lang-en {
    display: none;
}

.lang-zh {
    display: none;
}

.lang-zh.active {
    display: block !important;
}

.lang-en.active {
    display: block !important;
}

/* Glass Card */
.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: 12px;
    transition: all 0.3s ease;
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.15);
    padding: 1.5rem;
}

.glass-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 30px rgba(0, 212, 255, 0.4);
    border-color: var(--primary);
    background: rgba(255, 255, 255, 0.15);
}

/* Grid Layout */
.grid {
    display: grid;
    gap: 1.5rem;
}

.grid-cols-1 {
    grid-template-columns: repeat(1, 1fr);
}

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

.grid-cols-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-cols-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* Typography */
.text-5xl {
    font-size: 2.5rem;
}

.text-4xl {
    font-size: 1.875rem;
}

.text-2xl {
    font-size: 1.25rem;
}

.text-xl {
    font-size: 1.125rem;
}

.text-lg {
    font-size: 1rem;
}

.text-sm {
    font-size: 0.75rem;
}

.font-bold {
    font-weight: 700;
}

.font-medium {
    font-weight: 500;
}

/* Colors */
.text-gray-400 {
    color: #9ca3af;
}

.text-gray-500 {
    color: #6b7280;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: brightness(1.2);
}

/* Button */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    outline: none;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--background);
    box-shadow: 0 3px 10px rgba(0, 212, 255, 0.4);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(0, 212, 255, 0.6);
    filter: brightness(1.1);
}

/* Animations */
.float-animation {
    animation: float 3s ease-in-out infinite;
}

.pulse-glow {
    animation: pulseGlow 2s ease-in-out infinite;
}

.data-stream {
    position: relative;
    overflow: hidden;
}

.data-stream::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--primary), transparent);
    animation: dataFlow 2s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

@keyframes pulseGlow {
    0%, 100% { 
        box-shadow: 0 0 15px rgba(0, 212, 255, 0.4);
    }
    50% { 
        box-shadow: 0 0 30px rgba(0, 212, 255, 0.8);
    }
}

@keyframes dataFlow {
    0% { left: -100%; }
    100% { left: 100%; }
}

/* Spacing */
.mb-4 { margin-bottom: 0.75rem; }
.mb-6 { margin-bottom: 1rem; }
.mb-8 { margin-bottom: 1.5rem; }
.mb-10 { margin-bottom: 2rem; }
.mb-16 { margin-bottom: 2.5rem; }
.mb-20 { margin-bottom: 3rem; }

.space-y-4 > * + * { margin-top: 0.75rem; }

/* Flexbox */
.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.items-center {
    align-items: center;
}

.justify-center {
    justify-content: center;
}

.justify-between {
    justify-content: space-between;
}

/* Gap */
.gap-3 { gap: 0.5rem; }
.gap-10 { gap: 1.5rem; }

/* Responsive */
@media (min-width: 768px) {
    .md\:grid-cols-2 {
        grid-template-columns: repeat(2, 1fr);
    }
    .md\:grid-cols-3 {
        grid-template-columns: repeat(3, 1fr);
    }
    .md\:grid-cols-4 {
        grid-template-columns: repeat(4, 1fr);
    }
    .md\:text-7xl {
        font-size: 3.5rem;
    }
    .md\:text-2xl {
        font-size: 1.25rem;
    }
}

/* Max Width */
.max-w-2xl { max-width: 36rem; }
.max-w-3xl { max-width: 42rem; }
.max-w-5xl { max-width: 56rem; }
.max-w-6xl { max-width: 64rem; }

.mx-auto {
    margin-left: auto;
    margin-right: auto;
}

/* Leading */
.leading-relaxed {
    line-height: 1.5;
}

/* Image */
.drop-shadow-lg {
    filter: drop-shadow(0 8px 6px rgb(0 0 0 / 0.04)) drop-shadow(0 3px 2px rgb(0 0 0 / 0.1));
}

/* Divider */
.divider {
    width: 6rem;
    height: 0.2rem;
    background: linear-gradient(to right, transparent, var(--primary), transparent);
    border-radius: 9999px;
    margin: 0 auto;
}

.divider-gray {
    background: linear-gradient(to right, transparent, #6b7280, transparent);
}