/* Reset CSS for Android 4.0 and below compatibility */
/* 基础重置样式，适配Android 4.0以下版本 */

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

html, body {
    height: 100%;
    font-size: 16px;
    line-height: 1.5;
    font-family: Arial, sans-serif;
    background-color: #000;
    color: #fff;
    overflow: hidden; /* 防止滚动 */
    -webkit-text-size-adjust: 100%; /* 防止字体缩放 */
    -webkit-user-select: none; /* 禁用文本选择 */
    -webkit-touch-callout: none; /* 禁用触摸菜单 */
    -webkit-tap-highlight-color: transparent; /* 移除触摸高亮 */
}

html {
    font-size: 16px; /* 基准字体大小 */
}

/* 移除默认边框和轮廓 */
input, button, textarea, select {
    border: none;
    outline: none;
    background: transparent;
    font-family: inherit;
}

/* 按钮重置 */
button {
    cursor: pointer;
    -webkit-appearance: none;
    appearance: none;
}

/* 移除列表样式 */
ul, ol {
    list-style: none;
}

/* 链接样式 */
a {
    text-decoration: none;
    color: inherit;
}

/* 图片重置 */
img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* 视频重置 */
video {
    display: block;
    width: 100%;
    height: auto;
}

/* 表单元素 */
input, textarea {
    -webkit-appearance: none;
    appearance: none;
}

/* 表格重置 */
table {
    border-collapse: collapse;
    border-spacing: 0;
}

/* 隐藏元素 */
.hidden {
    display: none !important;
}

/* 可见性控制 */
.invisible {
    visibility: hidden;
}

/* 透明度 */
.opacity-0 { opacity: 0; }
.opacity-50 { opacity: 0.5; }
.opacity-100 { opacity: 1; }

/* 布局辅助类 */
.clearfix::after {
    content: '';
    display: table;
    clear: both;
}

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

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

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

/* Flexbox 兼容性 */
.flex {
    display: -webkit-box;
    display: -webkit-flex;
    display: flex;
}

.flex-column {
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
    -webkit-flex-direction: column;
    flex-direction: column;
}

.flex-row {
    -webkit-box-orient: horizontal;
    -webkit-flex-direction: row;
    flex-direction: row;
}

.flex-center {
    -webkit-box-pack: center;
    -webkit-box-align: center;
    -webkit-justify-content: center;
    -webkit-align-items: center;
    justify-content: center;
    align-items: center;
}

.flex-between {
    -webkit-box-pack: justify;
    -webkit-justify-content: space-between;
}

.flex-around {
    -webkit-justify-content: space-around;
}

.flex-wrap {
    -webkit-flex-wrap: wrap;
    flex-wrap: wrap;
}

/* 定位辅助 */
.relative {
    position: relative;
}

.absolute {
    position: absolute;
}

.fixed {
    position: fixed;
}

/* 尺寸辅助 */
.w-100 { width: 100%; }
.h-100 { height: 100%; }
.full-size {
    width: 100%;
    height: 100%;
}