/* 这是引入了一些字体 */
@import url('https://fonts.googleapis.com/css?family=Poppins:300,400,500,600,700,800,900&display=swap');

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
    /* 当用户手动导航或者 CSSOM scrolling API 触发滚动操作时 */
    scroll-behavior: smooth;
}

body {
    min-height: 100vh;
    overflow-x: hidden;
    background-image: url("飞船2.png");
    background-size: cover;
}

header {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    padding: 30px 100px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 10000;
}

header .logo {
    color: #fff;
    font-weight: 700;
    text-decoration: none;
    font-size: 2em;
    text-transform: uppercase; /* 大写 */
    letter-spacing: 2px; /* 字符间距 */
}

.logo-img {
    vertical-align: middle;
    margin: 0 10px;
    width: 50px;
}

header ul {
    display: flex;
    justify-content: center;
    align-items: center;
}

header ul li {
    list-style: none;
    margin-left: 20px;
}

header ul li a {
    text-decoration: none;
    padding: 6px 15px;
    color: #fff;
    border-radius: 20px;
}

header ul li a:hover,
header ul li a.active {
    background: #fff;
    color: #2b1055;
}

section {
    color: white;
    position: relative;
    width: 100%;
    height: 100vh;
    padding: 100px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

section::before {
    content: '';
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 100px;
    background: linear-gradient(to top, #1c0522, transparent);
    z-index: 1000;
}

section img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    /* object-fit CSS 属性指定可替换元素（例如：<img> 或 <video>）的内容应该如何适应到其使用高度和宽度确定的框。 */
    object-fit: cover;
    pointer-events: none;
}

section img#moon {
    /* mix-blend-mode CSS 属性描述了元素的内容应该与元素的直系父元素的内容和元素的背景如何混合。 */
    mix-blend-mode: screen;
}

section img#mountains_front {
    z-index: 10;
}

#text {
    position: absolute;
    right: -350px;
    color: #fff;
    white-space: nowrap;
    font-size: 7.5vw;
    z-index: 9;
}

#btn {
    text-decoration: none;
    display: inline-block;
    padding: 8px 30px;
    border-radius: 40px;
    background: #fff;
    color: #2b1055;
    font-size: 1.5em;
    z-index: 9;
    transform: translateY(100px);
}

.sec {
    position: relative;
    padding: 100px;
    background: #1c0522;
}

.sec h2 {
    font-size: 3.5em;
    margin-bottom: 10px;
    color: #fff;
}

.sec p {
    font-size: 1em;
    color: #fff;
}

#etp-timer {
    font-size: 2em;
    color: #ffffff;
    width: 100%;
    padding: 20px 30px;
    border-radius: 12px;
    max-width: 1000px;
    text-align: center;

    /* 背景透明 + 模糊 */
    background-color: rgba(255, 255, 255, 0.1); /* 半透明白底 */
    backdrop-filter: blur(2px); /* 毛玻璃效果 */
    -webkit-backdrop-filter: blur(2px); /* 兼容 Safari */

    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.time-value {
    color: #fff;
    font-weight: bold;
    text-shadow: 0 0 5px rgba(0, 0, 0, 0.5);
}

.join-button {
    display: block;
    margin-top: 20px;
    padding: 12px 30px;
    font-size: 1rem;
    color: #fff;
    background-color: dodgerblue;
    border: none;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    text-decoration: none;
}

.join-button:hover {
    transform: scale(1.05);
    background-color: dodgerblue;
}
.join-button:active {
    transform: scale(0.95);
}

.cards-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    padding: 40px 20px;
    margin-top: 250px;
    background-color: rgba(0, 0, 0, 0.3);
}

.card {
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    padding: 20px;
    width: calc(25% - 20px); /* 每行4个 */
    backdrop-filter: blur(10px);
    color: #fff;
    transition: transform 0.3s ease;
    max-width: 300px;
    text-align: left;
}

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

.card h3 {
    margin-bottom: 10px;
    font-size: 1.2em;
}

.card ol {
    margin-bottom: 20px;
    padding-left: 20px;
    font-size: 0.95em;
}

.submit-btn {
    display: inline-block;
    padding: 10px 20px;
    font-size: 0.9em;
    color: #fff;
    background-color: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
}

.submit-btn:hover {
    background-color: rgba(255, 255, 255, 0.3);
    transform: scale(1.05);
}

.submit-btn:active {
    transform: scale(0.98);
}