/* 全局变量 */
:root {
    --primary-color: #2563EB;
    --secondary-color: #F59E0B;
    --accent-color: #10B981;
    --dark-color: #1E293B;
    --light-color: #F8FAFC;
    --gradient-primary: linear-gradient(135deg, #2563EB, #1D4ED8);
    --gradient-secondary: linear-gradient(135deg, #F59E0B, #D97706);
    --text-primary: #1E293B;
    --text-secondary: #64748B;
    --text-light: #F8FAFC;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.75rem;
    --radius-lg: 1.5rem;
    --transition: all 0.3s ease;
    --primary-gradient: linear-gradient(135deg, #1a2a6c, #b21f1f, #fdbb2d);
    --secondary-gradient: linear-gradient(135deg, #00c6ff, #0072ff);
    --light-bg: #f8f9fa;
    --white: #ffffff;
}

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

body {
    font-family: 'Montserrat', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--light-color);
    overflow-x: hidden;
}

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

/* 布局容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: #2c3e50;
    font-weight: 600;
    font-size: 1.2rem;
    gap: 0.8rem;
    transition: all 0.3s ease;
}

.logo:hover {
    transform: translateY(-2px);
}

.logo img {
    height: 55px;
    width: auto;
    object-fit: contain;
    transition: all 0.3s ease;
}

.logo span {
    color: #2c3e50;
    font-weight: 700;
    letter-spacing: 0.5px;
}

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

.nav-links a {
    color: #2c3e50;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links a:hover {
    color: #3498db;
    transform: translateY(-2px);
}

.nav-links a i {
    font-size: 1.1rem;
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: #2c3e50;
    cursor: pointer;
}

/* 响应式导航栏 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: white;
        padding: 1rem;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    }

    .nav-links.active {
        display: flex;
        flex-direction: column;
        gap: 1rem;
    }

    .mobile-toggle {
        display: block;
    }

    .logo img {
        height: 45px;
    }
    
    .logo span {
        font-size: 1rem;
    }
}

/* 添加页面主体内容的上边距 */
main {
    margin-top: 80px;
    min-height: calc(100vh - 80px);
}

/* 调整header样式 */
header {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-gradient);
    color: var(--white);
    overflow: hidden;
}

.video-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0.2;
    z-index: 1;
}

.header-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.header-content h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    background: linear-gradient(to right, #ffffff, #f8f9fa);
    -webkit-background-clip: text;
    -moz-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.header-content p {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
}

/* 统计数字样式优化 */
.header-stats {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin: 3rem 0;
    flex-wrap: wrap;
}

.stat-item {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 1.5rem;
    border-radius: 1rem;
    min-width: 200px;
    transition: transform 0.3s ease;
}

.stat-item:hover {
    transform: translateY(-5px);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--white);
    display: block;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.9);
}

/* 倒计时区域样式优化 */
.countdown-section {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 2rem;
    border-radius: 1rem;
    margin: 2rem 0;
}

.countdown-section h2 {
    color: var(--white);
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
}

.countdown-container {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
}

.countdown-item {
    background: rgba(255, 255, 255, 0.2);
    padding: 1rem;
    border-radius: 0.5rem;
    min-width: 80px;
    text-align: center;
}

.countdown-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--white);
}

.countdown-label {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.9);
}

.offer-text {
    color: var(--white);
    font-size: 1.2rem;
    margin-top: 1rem;
    font-weight: 600;
}

/* 主题公园卡片样式 */
.parks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.park-card {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
}

.park-card:hover {
    transform: translateY(-10px);
}

.park-image {
    position: relative;
    overflow: hidden;
}

.park-image img {
    width: 100%;
    height: 250px;
    object-fit: cover;
    transition: var(--transition);
}

.park-card:hover .park-image img {
    transform: scale(1.05);
}

/* 标签样式优化 */
.park-badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: #e74c3c;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    z-index: 1;
    animation: badgePulse 2s infinite;
}

.park-content {
    padding: 2rem;
}

.park-content h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.park-features {
    list-style: none;
    margin: 1.5rem 0;
}

.park-features li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
}

.park-features i {
    color: var(--accent-color);
}

.park-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid rgba(0,0,0,0.1);
}

.park-rating {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    color: var(--secondary-color);
}

/* 按钮样式优化 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.8rem 1.5rem;
    font-weight: 600;
    border-radius: 50px;
    transition: all 0.3s ease;
    text-decoration: none;
    gap: 0.5rem;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.9rem;
}

.btn-primary {
    background: var(--secondary-gradient);
    color: var(--white);
    border: none;
    padding: 1rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.btn-primary:active {
    transform: translateY(1px);
}

.btn-primary i {
    font-size: 1.1rem;
    transition: transform 0.3s ease;
}

.btn-primary:hover i {
    transform: translateX(3px);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--white);
    color: var(--white);
    padding: 1rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-3px);
}

/* 套餐卡片中的按钮样式 */
.package-card .btn-primary {
    width: 100%;
    margin-top: 1.5rem;
    padding: 1rem;
    font-size: 1rem;
}

/* 主题公园卡片中的按钮样式 */
.park-footer .btn-primary {
    padding: 0.7rem 1.2rem;
    font-size: 0.85rem;
}

/* 虚拟体验按钮样式 */
.preview-overlay .btn-primary {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

/* 倒计时区域按钮样式 */
.countdown-section .btn-primary {
    margin-top: 1.5rem;
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

/* 按钮动画效果 */
@keyframes buttonPulse {
    0% {
        box-shadow: 0 0 0 0 rgba(255, 75, 43, 0.4);
    }
    70% {
        box-shadow: 0 0 0 10px rgba(255, 75, 43, 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(255, 75, 43, 0);
    }
}

.pulse-animation {
    animation: buttonPulse 2s infinite;
}

/* 链接悬停效果 */
a:not(.btn) {
    color: #FF4B2B;
    text-decoration: none;
    transition: color 0.3s ease;
}

a:not(.btn):hover {
    color: #FF416C;
    text-decoration: underline;
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

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

.pulse-animation {
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .header-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .parks-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 1rem;
        transform: translateY(-150%);
        transition: var(--transition);
        box-shadow: var(--shadow-md);
    }
    
    .nav-links.active {
        transform: translateY(0);
    }
    
    .mobile-toggle {
        display: block;
    }
    
    .parks-grid {
        grid-template-columns: 1fr;
    }
    
    .countdown-container {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .countdown-item {
        min-width: 45%;
    }
}

@media (max-width: 480px) {
    .header-stats {
        grid-template-columns: 1fr;
    }
    
    .countdown-item {
        min-width: 100%;
    }
    
    .btn {
        width: 100%;
        margin-bottom: 1rem;
    }
}

/* Footer Styles */
footer {
    background-color: #1a1a1a;
    color: #ffffff;
    padding: 2rem 0;
    margin-top: 4rem;
}

.footer-bottom {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1rem;
}

.copyright {
    font-size: 0.9rem;
    color: #ffffff;
    opacity: 0.8;
    line-height: 1.5;
}

.footer-legal {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.footer-legal a {
    color: #ffffff;
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.footer-legal a:hover {
    color: #f0f0f0;
}

.footer-legal span {
    color: #ffffff;
    opacity: 0.5;
}

@media (max-width: 768px) {
    .footer-bottom {
        padding: 0 1rem;
    }
    
    .copyright {
        font-size: 0.8rem;
    }
    
    .footer-legal {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .footer-legal span {
        display: none;
    }
}

/* 卡片样式优化 */
.feature-card, .park-card, .package-card {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover, .park-card:hover, .package-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.2);
}

/* 倒计时样式优化 */
.countdown {
    background: var(--gradient-primary);
    color: white;
    padding: 4rem 0;
    position: relative;
    overflow: hidden;
}

.countdown::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="2"/></svg>') repeat;
    opacity: 0.1;
}

.countdown-container {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin: 2rem 0;
}

.countdown-item {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(5px);
    padding: 1.5rem;
    border-radius: 15px;
    min-width: 120px;
    text-align: center;
}

.countdown-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--secondary-color);
    display: block;
    margin-bottom: 0.5rem;
}

.pulse-animation {
    animation: pulse 2s infinite;
}

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

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

/* 360°虚拟体验部分样式 */
.virtual-experience {
    padding: 5rem 0;
    background: linear-gradient(to bottom, var(--light-color), #f0f9ff);
}

.virtual-experience .section-title {
    text-align: center;
    margin-bottom: 3rem;
}

.virtual-experience .section-title h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.virtual-experience .section-title p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 800px;
    margin: 0 auto;
}

.experience-preview {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    margin-bottom: 3rem;
}

.experience-preview img {
    width: 100%;
    height: auto;
    transition: transform 0.3s ease;
}

.experience-preview:hover img {
    transform: scale(1.02);
}

.preview-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.3);
    transition: background 0.3s ease;
}

.preview-overlay:hover {
    background: rgba(0, 0, 0, 0.5);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.tour-description {
    text-align: center;
    margin-bottom: 3rem;
}

.tour-description p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.tour-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    list-style: none;
    padding: 0;
}

.tour-features li {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.tour-features li:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.tour-features i {
    color: var(--accent-color);
    font-size: 1.25rem;
}

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

.app-downloads h3 {
    font-size: 1.75rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
}

.app-buttons {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.app-button {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 2rem;
    background: white;
    border-radius: var(--radius-md);
    text-decoration: none;
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.app-button:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.app-button i {
    font-size: 2rem;
}

.app-button span {
    font-weight: 500;
}

@media (max-width: 768px) {
    .virtual-experience {
        padding: 3rem 0;
    }
    
    .virtual-experience .section-title h2 {
        font-size: 2rem;
    }
    
    .tour-features {
        grid-template-columns: 1fr;
    }
    
    .app-buttons {
        flex-direction: column;
        gap: 1rem;
    }
    
    .app-button {
        width: 100%;
        justify-content: center;
    }
}

/* 套餐卡片样式 */
.packages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2.5rem;
    margin-top: 3rem;
}

.package-card {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
    position: relative;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.package-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.package-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid var(--light-color);
}

.package-header h3 {
    font-size: 1.75rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.package-price {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--secondary-color);
    display: block;
}

.price-note {
    font-size: 1rem;
    color: var(--text-secondary);
    display: block;
    margin-top: 0.5rem;
}

.package-content {
    flex: 1;
    margin-bottom: 2rem;
}

.package-features {
    list-style: none;
    padding: 0;
    margin: 0;
}

.package-features li {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    margin-bottom: 0.5rem;
    background: var(--light-color);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.package-features li:hover {
    background: rgba(37, 99, 235, 0.05);
    transform: translateX(5px);
}

.package-features li i {
    color: var(--accent-color);
    font-size: 1.25rem;
}

.package-card .btn {
    width: 100%;
    padding: 1rem;
    font-size: 1.1rem;
    margin-top: auto;
}

.popular-tag {
    position: absolute;
    top: -1rem;
    right: 1rem;
    background: #2ecc71;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    z-index: 1;
}

.limited-offer {
    background: var(--gradient-primary);
    color: white;
    padding: 2rem;
    border-radius: var(--radius-lg);
    margin-bottom: 3rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.limited-offer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="2"/></svg>') repeat;
    opacity: 0.1;
}

.limited-offer h3 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.limited-offer p {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
}

.remaining {
    font-size: 2rem;
    font-weight: 700;
    color: var(--secondary-color);
}

@media (max-width: 768px) {
    .packages-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .package-card {
        padding: 1.5rem;
    }
    
    .package-header h3 {
        font-size: 1.5rem;
    }
    
    .package-price {
        font-size: 2rem;
    }
}

/* 标签样式优化 */
.park-badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: #e74c3c;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    z-index: 1;
    animation: badgePulse 2s infinite;
}

.popular-tag {
    position: absolute;
    top: -1rem;
    right: 1rem;
    background: #2ecc71;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    z-index: 1;
}

@keyframes badgePulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

/* 按钮悬停效果优化 */
.btn {
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.btn-primary {
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
    border: none;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #2980b9 0%, #3498db 100%);
}

/* 滚动提示样式 */
.scroll-hint {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: white;
    opacity: 0.8;
}

.scroll-hint i {
    display: block;
    font-size: 2rem;
    margin-bottom: 0.5rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-20px);
    }
    60% {
        transform: translateY(-10px);
    }
}

/* 回到顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: #3498db;
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

.back-to-top.visible {
    opacity: 1;
}

.back-to-top:hover {
    background: #2980b9;
    transform: translateY(-5px);
}