/* Global Resets & Common Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    background: #f7f7f7;
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-position: 50% 50%;
    padding-top: 80px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

a {
    text-decoration: none;
    color: rgb(57, 57, 57);
    transition: color 0.3s;
}

a:hover {
    color: #000;
}

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

h2 {
    font-size: 20px;
}

.tinytyper {
    font-size: 3rem;
    margin-top: 10px;
    text-align: center;
}

/* Common Layout Boxes */
.article-c, .box-b {
    width: 70%;
    text-align: center;
    padding: 20px;
    height: auto;
    margin: 0 auto;
}

.box-b {
    text-align: center;
    margin-bottom: 10px;
}

.box-c {
    background: white;
    border-color: #EEEEEE;
    box-shadow: 0 0 10px 0 rgb(0 0 0 / 6%);
    margin: 0 auto;
    border: 1px solid #eee;
    border-radius: 0 0 10px 10px;
    padding: 20px;
}

#box {
    width: 80%;
    margin: 14vh auto 0;
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background-color: #007bff;
    color: #fff;
    border-radius: 50%;
    text-align: center;
    line-height: 50px;
    font-size: 20px;
    cursor: pointer;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    text-decoration: none;
    transform: translateY(20px);
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background-color: #0056b3;
    transform: translateY(-3px);
    color: #fff;
}

/* 图片懒加载样式 (仿 WP-Rocket) */
img.lazyload {
    opacity: 0;
}

img.loaded {
    opacity: 1;
    transition: opacity 0.6s ease-in-out;
}