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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    overflow-x: hidden;
    overflow-y: auto;
    background: #000;
    -webkit-tap-highlight-color: transparent;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    user-select: none;
}

.container {
    width: 100vw;
    min-height: 100vh;
    position: relative;
    transition: all 0.8s ease;
    padding-bottom: 80px;
    display: flex;
    flex-direction: column;
}

/* AI主题样式 */
.container.ai {
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a2e 50%, #16213e 100%);
}

.container.ai .theme-btn.active {
    background: linear-gradient(45deg, #00d4ff, #0099cc);
    box-shadow: 0 0 30px rgba(0, 212, 255, 0.5);
}

.container.ai .feature-card {
    background: linear-gradient(145deg, rgba(0, 212, 255, 0.1), rgba(0, 153, 204, 0.05));
    border: 1px solid rgba(0, 212, 255, 0.3);
}

.container.ai .title {
    color: #00d4ff;
    text-shadow: 0 0 20px rgba(0, 212, 255, 0.5);
}

/* 数字孪生主题样式 */
.container.digital-twin {
    background: linear-gradient(135deg, #0a0a0a 0%, #2e1a1a 50%, #3e1616 100%);
}

.container.digital-twin .theme-btn.active {
    background: linear-gradient(45deg, #ff6b6b, #ee5a52);
    box-shadow: 0 0 30px rgba(255, 107, 107, 0.5);
}

.container.digital-twin .feature-card {
    background: linear-gradient(145deg, rgba(255, 107, 107, 0.1), rgba(238, 90, 82, 0.05));
    border: 1px solid rgba(255, 107, 107, 0.3);
}

.container.digital-twin .title {
    color: #ff6b6b;
    text-shadow: 0 0 20px rgba(255, 107, 107, 0.5);
}

/* 背景动画 */
.background-animation {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 1;
}

/* AI主题：动态星空背景 */
.ai-background {
    width: 100%;
    height: 100%;
    position: relative;
}

.stars-layer {
    position: absolute;
    width: 100%;
    height: 100%;
}

.star {
    position: absolute;
    width: 2px;
    height: 2px;
    background: white;
    border-radius: 50%;
    animation: starTwinkle infinite ease-in-out;
}

@keyframes starTwinkle {
    0%, 100% {
        opacity: 0.3;
        transform: scale(1);
    }
    50% {
        opacity: 1;
        transform: scale(1.5);
    }
}

.nebula-layer {
    position: absolute;
    width: 100%;
    height: 100%;
}

.nebula {
    position: absolute;
    border-radius: 50%;
    filter: blur(40px);
    animation: nebulaFloat 20s infinite ease-in-out;
}

.nebula-1 {
    width: 300px;
    height: 200px;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.1) 0%, transparent 70%);
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.nebula-2 {
    width: 250px;
    height: 180px;
    background: radial-gradient(circle, rgba(100, 200, 255, 0.08) 0%, transparent 70%);
    top: 60%;
    right: 20%;
    animation-delay: -7s;
}

.nebula-3 {
    width: 200px;
    height: 150px;
    background: radial-gradient(circle, rgba(200, 230, 255, 0.06) 0%, transparent 70%);
    top: 40%;
    left: 60%;
    animation-delay: -14s;
}

@keyframes nebulaFloat {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    33% {
        transform: translate(30px, -20px) scale(1.1);
    }
    66% {
        transform: translate(-20px, 30px) scale(0.9);
    }
}

.shooting-stars {
    position: absolute;
    width: 100%;
    height: 100%;
}

.shooting-star {
    position: absolute;
    top: -5px;
    width: 2px;
    height: 100px;
    background: linear-gradient(to bottom,
        rgba(255, 255, 255, 1) 0%,
        rgba(255, 255, 255, 0.8) 20%,
        rgba(100, 200, 255, 0.6) 40%,
        transparent 100%);
    transform: rotate(45deg);
    animation: shootingStarFall infinite linear;
}

@keyframes shootingStarFall {
    0% {
        transform: translateY(-100px) translateX(0) rotate(45deg);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(100vh) translateX(-200px) rotate(45deg);
        opacity: 0;
    }
}

/* 数字孪生主题：一真一假对比背景 */
.digital-twin-background {
    width: 100%;
    height: 100%;
    position: relative;
    display: flex;
}

.real-world {
    width: 50%;
    height: 100%;
    position: relative;
    background: linear-gradient(to bottom, #1a1a2e 0%, #16213e 100%);
}

.digital-world {
    width: 50%;
    height: 100%;
    position: relative;
    background: linear-gradient(to bottom, #2e1a1a 0%, #3e1616 100%);
}

.divider-line {
    position: absolute;
    left: 50%;
    top: 0;
    width: 2px;
    height: 100%;
    background: linear-gradient(to bottom,
        transparent 0%,
        rgba(255, 107, 107, 0.8) 20%,
        rgba(255, 107, 107, 1) 50%,
        rgba(255, 107, 107, 0.8) 80%,
        transparent 100%);
    animation: dividerPulse 2s infinite ease-in-out;
    z-index: 5;
}

@keyframes dividerPulse {
    0%, 100% {
        opacity: 0.6;
        transform: translateX(-50%) scaleY(1);
    }
    50% {
        opacity: 1;
        transform: translateX(-50%) scaleY(1.05);
    }
}

/* 真实城市 */
.real-city {
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 60%;
}

.building {
    position: absolute;
    bottom: 0;
    background: linear-gradient(to top, #2c3e50 0%, #34495e 100%);
    border-radius: 2px 2px 0 0;
    animation: buildingGlow 3s infinite ease-in-out;
}

@keyframes buildingGlow {
    0%, 100% {
        box-shadow: 0 0 5px rgba(52, 152, 219, 0.3);
    }
    50% {
        box-shadow: 0 0 15px rgba(52, 152, 219, 0.6);
    }
}

.real-lights {
    position: absolute;
    width: 100%;
    height: 100%;
}

.light {
    position: absolute;
    width: 3px;
    height: 3px;
    background: #f39c12;
    border-radius: 50%;
    animation: lightFlicker 2s infinite ease-in-out;
}

@keyframes lightFlicker {
    0%, 100% {
        opacity: 0.6;
        transform: scale(1);
    }
    50% {
        opacity: 1;
        transform: scale(1.3);
    }
}

/* 数字城市 */
.digital-city {
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 60%;
}

.digital-building {
    position: absolute;
    bottom: 0;
    background: linear-gradient(to top, 
        rgba(255, 107, 107, 0.1) 0%, 
        rgba(255, 107, 107, 0.3) 100%);
    border: 1px solid rgba(255, 107, 107, 0.5);
    border-radius: 2px 2px 0 0;
    animation: digitalBuildingPulse 2s infinite ease-in-out;
}

@keyframes digitalBuildingPulse {
    0%, 100% {
        border-color: rgba(255, 107, 107, 0.5);
        box-shadow: 0 0 10px rgba(255, 107, 107, 0.2);
    }
    50% {
        border-color: rgba(255, 107, 107, 0.8);
        box-shadow: 0 0 20px rgba(255, 107, 107, 0.4);
    }
}

.digital-grid {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(255, 107, 107, 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 107, 107, 0.1) 1px, transparent 1px);
    background-size: 20px 20px;
    animation: gridMove 10s infinite linear;
}

@keyframes gridMove {
    0% {
        transform: translate(0, 0);
    }
    100% {
        transform: translate(20px, 20px);
    }
}

.data-streams {
    position: absolute;
    width: 100%;
    height: 100%;
}

.data-stream {
    position: absolute;
    top: 0;
    width: 2px;
    height: 30px;
    background: linear-gradient(to bottom,
        rgba(255, 107, 107, 1) 0%,
        rgba(255, 107, 107, 0.5) 50%,
        transparent 100%);
    animation: dataStreamFlow infinite linear;
}

@keyframes dataStreamFlow {
    0% {
        transform: translateY(-30px);
        opacity: 0;
    }
    20% {
        opacity: 1;
    }
    80% {
        opacity: 1;
    }
    100% {
        transform: translateY(100vh);
        opacity: 0;
    }
}

/* 连接线效果 */
.connection-lines {
    position: absolute;
    width: 100%;
    height: 100%;
    z-index: 3;
}

.connection-line {
    position: absolute;
    left: 25%;
    width: 50%;
    height: 2px;
    background: linear-gradient(to right,
        rgba(0, 212, 255, 0.8) 0%,
        rgba(255, 107, 107, 0.8) 100%);
    animation: connectionPulse 3s infinite ease-in-out;
}

@keyframes connectionPulse {
    0%, 100% {
        opacity: 0.3;
        transform: scaleX(0.8);
    }
    50% {
        opacity: 1;
        transform: scaleX(1);
    }
}

/* 主题切换按钮 */
.theme-switcher {
    position: relative;
    top: 0;
    display: flex;
    justify-content: center;
    gap: 20px;
    z-index: 100;
    padding: 30px 0 20px 0;
}

.theme-btn {
    padding: 15px 30px;
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 50px;
    color: white;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
    font-weight: 600;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

.theme-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

.theme-btn:active {
    transform: translateY(0);
}

.btn-icon {
    font-size: 20px;
}

/* 主要内容区域 */
.main-content {
    position: relative;
    width: 90%;
    max-width: 1200px;
    z-index: 10;
    margin: 0 auto;
    padding: 20px 0 40px 0;
}

.content-panel {
    text-align: center;
    animation: fadeIn 0.8s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 40px;
    letter-spacing: 2px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.feature-card {
    padding: 30px;
    border-radius: 20px;
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.feature-card h3 {
    color: white;
    font-size: 1.5rem;
    margin-bottom: 15px;
    font-weight: 600;
}

.feature-card p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.6;
    font-size: 1rem;
}

/* 状态栏 */
.status-bar {
    position: fixed;
    top: 20px;
    right: 30px;
    display: flex;
    gap: 30px;
    z-index: 100;
}

.status-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
}

.status-dot {
    width: 8px;
    height: 8px;
    background: #00ff88;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

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

/* 页脚 */
.footer {
    position: relative;
    bottom: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
    margin-top: auto;
}

.footer-divider {
    width: 100%;
    height: 1px;
    background: linear-gradient(to right, 
        transparent 0%, 
        rgba(255, 255, 255, 0.3) 50%, 
        transparent 100%);
}

.footer-content {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
    padding: 15px 20px;
    color: rgba(255, 255, 255, 0.6);
    font-size: 13px;
}

.footer-separator {
    color: rgba(255, 255, 255, 0.3);
}

/* 响应式设计 */
@media (max-width: 768px) {
    body {
        overflow-y: auto;
        overflow-x: hidden;
    }
    
    .container {
        min-height: 100vh;
        padding-bottom: 0;
    }
    
    .theme-switcher {
        padding: 20px 10px 15px 10px;
        flex-direction: row;
        gap: 10px;
    }
    
    .theme-btn {
        padding: 10px 15px;
        font-size: 13px;
        flex: 1;
    }
    
    .btn-icon {
        font-size: 18px;
    }
    
    .btn-text {
        font-size: 12px;
    }
    
    .title {
        font-size: 2rem;
        margin-bottom: 30px;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .main-content {
        width: 95%;
        padding: 15px 0 30px 0;
    }
    
    .feature-card {
        padding: 20px;
    }
    
    .card-icon {
        font-size: 2.5rem;
        margin-bottom: 15px;
    }
    
    .feature-card h3 {
        font-size: 1.2rem;
        margin-bottom: 10px;
    }
    
    .feature-card p {
        font-size: 0.9rem;
    }
    
    .status-bar {
        top: 15px;
        right: 15px;
        left: auto;
        flex-direction: row;
        gap: 15px;
        font-size: 11px;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 8px;
        padding: 15px;
        font-size: 12px;
    }
    
    .footer-separator {
        display: none;
    }
    
    /* 移动端背景优化 */
    .nebula {
        filter: blur(30px);
    }
    
    .nebula-1 {
        width: 200px;
        height: 150px;
    }
    
    .nebula-2 {
        width: 180px;
        height: 130px;
    }
    
    .nebula-3 {
        width: 150px;
        height: 100px;
    }
    
    /* 数字孪生背景移动端优化 */
    .digital-twin-background {
        flex-direction: column;
    }
    
    .real-world,
    .digital-world {
        width: 100%;
        height: 50%;
    }
    
    .divider-line {
        left: 0;
        top: 50%;
        width: 100%;
        height: 2px;
        transform: translateY(-50%);
    }
    
    @keyframes dividerPulse {
        0%, 100% {
            opacity: 0.6;
            transform: translateY(-50%) scaleX(1);
        }
        50% {
            opacity: 1;
            transform: translateY(-50%) scaleX(1.05);
        }
    }
    
    .connection-line {
        left: 10%;
        width: 80%;
    }
}

/* 小屏幕手机优化 */
@media (max-width: 480px) {
    .theme-switcher {
        gap: 8px;
    }
    
    .theme-btn {
        padding: 8px 12px;
        font-size: 12px;
    }
    
    .btn-icon {
        font-size: 16px;
    }
    
    .btn-text {
        display: none;
    }
    
    .title {
        font-size: 1.5rem;
        margin-bottom: 20px;
    }
    
    .feature-card {
        padding: 15px;
    }
    
    .card-icon {
        font-size: 2rem;
    }
    
    .feature-card h3 {
        font-size: 1rem;
    }
    
    .feature-card p {
        font-size: 0.85rem;
    }
}

/* 横屏模式优化 */
@media (max-width: 768px) and (orientation: landscape) {
    .main-content {
        padding: 15px 0 30px 0;
    }
    
    .title {
        font-size: 1.8rem;
        margin-bottom: 20px;
    }
    
    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }
}