/* 基础重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft Yahei", "Inter", system-ui, sans-serif;
}

body {
    color: var(--color-dark);
    background-color: #fff;
    line-height: 1.6;
}

/* 通用工具类 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section-padding {
    padding: 60px 0;
}

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

.card-hover {
    transition: var(--transition-default);
}

.card-hover:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.btn-primary {
    display: inline-block;
    background-color: var(--color-primary);
    color: #fff;
    font-weight: 500;
    padding: 12px 32px;
    border-radius: var(--radius-md);
    transition: var(--transition-default);
    box-shadow: var(--shadow-lg);
    text-decoration: none;
    border: none;
    cursor: pointer;
    font-size: 16px;
}

.btn-primary:hover {
    background-color: rgba(13, 148, 136, 0.9);
    box-shadow: 0 10px 25px rgba(13, 148, 136, 0.3);
}

.btn-secondary {
    display: inline-block;
    background-color: #fff;
    color: var(--color-primary);
    font-weight: 500;
    padding: 12px 32px;
    border-radius: var(--radius-md);
    transition: var(--transition-default);
    box-shadow: var(--shadow-md);
    text-decoration: none;
    border: 1px solid var(--color-primary);
    cursor: pointer;
    font-size: 16px;
}

.btn-secondary:hover {
    background-color: var(--color-gray-light);
    box-shadow: var(--shadow-lg);
}

/* 回到顶部按钮 */
#backToTop {
    position: fixed;
    bottom: 32px;
    right: 32px;
    background-color: var(--color-primary);
    color: #fff;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-default);
    cursor: pointer;
    border: none;
    font-size: 20px;
}

#backToTop:hover {
    background-color: rgba(13, 148, 136, 0.9);
}

#backToTop.show {
    opacity: 1;
    visibility: visible;
}

.fade-in {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1),
    transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}