* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}

body {
    background-color: #fff;
    color: #333;
    overflow-x: hidden;
}

.section-title {
    font-size: 32px;
    font-weight: bold;
    color: #333;
    margin-bottom: 40px;
    text-align: center;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background-color: #333;
    margin: 15px auto 0;
    border-radius: 2px;
}

header {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 100;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 30px;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo {
    width: 40px;
    height: 40px;
}

.nav-logo-text {
    font-size: 20px;
    font-weight: bold;
    color: #333;
}

.hamburger {
    width: 30px;
    height: 24px;
    position: relative;
    cursor: pointer;
    z-index: 101;
    display: block;
}

.bar {
    position: absolute;
    width: 100%;
    height: 3px;
    background-color: #333;
    border-radius: 3px;
    transition: all 0.3s ease;
}

.bar:nth-child(1) {
    top: 0;
}

.bar:nth-child(2) {
    top: 50%;
    transform: translateY(-50%);
}

.bar:nth-child(3) {
    bottom: 0;
}

.sidebar {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    height: 0;
    background-color: #333;
    overflow: hidden;
    transition: height 0.4s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.3s ease;
    z-index: 99;
    box-sizing: border-box;
    opacity: 0;
    transform: translateY(-10px);
}

.sidebar.active {
    height: 220px;
    padding: 25px 0;
    opacity: 1;
    transform: translateY(0);
    transition: height 0.4s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.3s ease, transform 0.3s ease;
}

.sidebar ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 18px;
    align-items: center;
    width: 100%;
    padding: 0;
    margin: 0;
}

.sidebar-list-item {
    width: 92%;
    max-width: 380px;
    text-align: center;
    cursor: pointer;
    padding: 12px 0;
    border-radius: 8px;
    transition: background-color 0.2s ease;
}

.sidebar-list-item:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.sidebar-list-item a {
    color: #fff;
    text-decoration: none;
    font-size: 18px;
    font-weight: 500;
    display: block;
    width: 100%;
    height: 100%;
}

.item {
    margin-bottom: 12px;
    border-radius: 8px;
    overflow: hidden;
    background: #fff;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0);
    transition: box-shadow 0.3s ease;
}

.item:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0);
}

.item-title {
    width: 100%;
    padding: 16px;
    text-align: left;
    border: none;
    background: #fff;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

.item-title:hover {
    background: #ECF0F1;
}

.item-title::after {
    content: '▼';
    font-size: 14px;
    color: #7f8c8d;
    transition: transform 0.4s cubic-bezier(0.68, -0.55, 0.27, 1.55);
}

.item.active .item-title::after {
    transform: rotate(180deg) scale(1.1);
}

.item-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 1s cubic-bezier(0.34, 1.56, 0.64, 1), padding 0.4s ease, opacity 0.1s ease;
    padding: 0 16px;
    opacity: 0;
}

.item.active .item-content {
    max-height: 1500px;
    padding: 16px;
    opacity: 1;
}

.item-content img {
    width: 100%;
    height: auto;
    border-radius: 4px;
    margin: 12px 0;
}

.item-content p {
    color: #34495e;
    line-height: 1.6;
    margin-bottom: 8px;
    text-align: center;
}

.scroll-tip {
    position: absolute;
    bottom: 60px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    color: #666;
    font-size: 14px;
    animation: fadeIn 1s ease-out;
}

.scroll-icon {
    display: flex;
    flex-direction: column;
    gap: 4px;
    align-items: center;
}

.scroll-icon .dot {
    display: block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: #666;
    animation: bounce 1.5s infinite ease-in-out;
}

.scroll-icon .dot:nth-child(2) {
    animation-delay: 0.3s;
}

.scroll-icon .dot:nth-child(3) {
    animation-delay: 0.6s;
}

@keyframes bounce {

    0%,
    100% {
        transform: translateY(0);
        opacity: 0.6;
    }

    50% {
        transform: translateY(-8px);
        opacity: 1;
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translate(-50%, 20px);
    }

    to {
        opacity: 1;
        transform: translate(-50%, 0);
    }
}

.hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding-top: 80px;
    position: relative;
}

.main-title {
    font-size: 80px;
    margin-bottom: 20px;
    color: #333;
}

.sub-title {
    font-size: 24px;
    color: #666;
    margin-bottom: 40px;
}

.cta-btn {
    padding: 15px 40px;
    background-color: #333;
    color: #fff;
    text-decoration: none;
    font-size: 18px;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.cta-btn:hover {
    background-color: #555;
}

.features {
    padding: 100px 50px;
    background-color: #fafafa;
}

.pricing {
    padding: 100px 50px;
    background-color: #f9f9f9;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
}

.pricing-selector-card {
    width: 100%;
    max-width: 600px;
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    padding: 25px;
    display: flex;
    justify-content: space-between;
}

.selector-item {
    width: 48%;
    padding: 20px;
    border-radius: 8px;
    background-color: #f5f5f5;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.selector-item.active {
    background-color: #333;
    color: #fff;
}

.selector-item h4 {
    font-size: 18px;
    margin-bottom: 8px;
}

.selector-item p {
    font-size: 14px;
    color: #666;
}

.selector-item.active p {
    color: #ddd;
}

.pricing-container {
    width: 100%;
    max-width: 350px;
    overflow: hidden;
    position: relative;
}

.pricing-slider {
    display: flex;
    transition: transform 0.5s ease;
    width: calc(2 * 350px);
}

.pricing-card {
    width: 350px;
    background-color: #fff;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    text-align: center;
    flex-shrink: 0;
}

.pricing-card h3 {
    font-size: 24px;
    margin-bottom: 20px;
    color: #333;
}

.price {
    font-size: 36px;
    font-weight: bold;
    color: #333;
    margin-bottom: 20px;
}

.plan-desc {
    color: #666;
    margin-bottom: 30px;
    line-height: 1.5;
    text-align: left;
}

.buy-btn {
    display: inline-block;
    padding: 12px 30px;
    background-color: #333;
    color: #fff;
    text-decoration: none;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.buy-btn:hover {
    background-color: #555;
}

.footer {
    text-align: center;
}

.hamburger.active .bar:nth-child(1) {
    top: 50%;
    transform: translateY(-50%) rotate(45deg);
}

.hamburger.active .bar:nth-child(2) {
    opacity: 0;
}

.hamburger.active .bar:nth-child(3) {
    bottom: 50%;
    transform: translateY(50%) rotate(-45deg);
}

@media (max-width: 768px) {
    .section-title {
        font-size: 28px;
    }

    .main-title {
        font-size: 60px;
    }

    .sub-title {
        font-size: 20px;
    }

    .features {
        padding: 80px 30px;
    }

    .pricing {
        padding: 80px 30px;
    }

    .pricing-selector-card {
        flex-direction: column;
        gap: 15px;
    }

    .selector-item {
        width: 100%;
    }

    .pricing-container {
        max-width: 300px;
    }

    .pricing-slider {
        width: calc(2 * 300px);
    }

    .pricing-card {
        width: 300px;
        padding: 30px;
    }

    .footer {
        padding: 60px 30px 30px;
    }

    .scroll-tip {
        bottom: 40px;
        font-size: 13px;
    }

    .scroll-icon .dot {
        width: 7px;
        height: 7px;
    }

    .sidebar.active {
        height: 200px;
        padding: 20px 0;
    }

    .sidebar ul {
        gap: 15px;
    }

    .sidebar-list-item {
        padding: 10px 0;
        max-width: 320px;
    }

    .sidebar-list-item a {
        font-size: 16px;
    }
}