diff --git a/first.css b/first.css
new file mode 100644
index 0000000..dccdde4
--- /dev/null
+++ b/first.css
@@ -0,0 +1,279 @@
+* {
+    margin: 0;
+    padding: 0;
+    box-sizing: border-box;
+    text-transform: capitalize;
+    outline: none;
+    border: none;
+    text-decoration: none;
+    transition: all .2s linear;
+    scroll-behavior: smooth;
+}
+
+/* 导航栏.css */
+header {
+    position: fixed;
+    top: 0;
+    left: 0;
+    right: 0;
+    background: #333;
+    z-index: 1000;
+    display: flex;
+    align-items: center;
+    /*垂直参数分布*/
+    justify-content: center;
+    /*水平参数分布*/
+    padding: 1rem 5%;
+}
+
+header .logo span {
+    color: #b0d8ff;
+}
+
+header .logo {
+    font-size: 1.5rem;
+    font-weight: bolder;
+    color: #fff;
+    text-transform: uppercase;
+}
+
+header .navbar a {
+    color: #fff;
+    font-size: 1rem;
+    font-weight: bold;
+    margin: 0 .8rem;
+}
+
+header .navbar a:hover {
+    color: #b0d8ff;
+}
+
+/*搜索*/
+header .search form {
+    position: relative;
+    width: 400px;
+    max-width: 100%;
+}
+
+header .search form input {
+    border: 0;
+    border-radius: 50px;
+    font-size: 16px;
+    padding: 15px 30px;
+    width: 100%;
+}
+
+header .search form button {
+    position: absolute;
+    top: 2px;
+    right: 2px;
+    background-color: #0A64B4;
+    border: 0;
+    border-radius: 50px;
+    color: #fff;
+    font-size: 16px;
+    padding: 13px 30px;
+}
+
+
+
+/* 登录表单 */
+header .login a {
+    position: fixed;
+    top: 2px;
+    right: 2px;
+    background-color: #5abcdd;
+    border: 0;
+    border-radius: 50px;
+    font-size: 16px;
+    padding: 13px 30px;
+}
+
+header .login a button {
+    background-color: #5abcdd;
+    font-size: 20px;
+    color: white;
+}
+
+header .login a button:hover {
+    color: #b0d8ff;
+}
+
+/* 主页的视频播放区 */
+
+.home {
+    min-height: 100vh;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    flex-direction: column;
+    position: relative;
+    z-index: 0;
+}
+
+.home .content {
+    text-align: center;
+}
+
+.home .content h3 {
+    font-size: 2rem;
+    color: #fff;
+    text-transform: uppercase;
+    text-shadow: 0 .3rem .5rem rgba(0, 0, 0, .1);
+}
+
+.home .content p {
+    font-size: 2rem;
+    color: #fff;
+    padding: .5rem 0;
+}
+
+.home .video-container video {
+    position: absolute;
+    top: 0;
+    left: 0;
+    z-index: -1;
+    height: 100%;
+    width: 100%;
+    object-fit: cover;
+}
+
+
+.home .controls {
+    padding: 0.5rem;
+    border-radius: 4rem;
+    background: #5abcdd;
+    position: relative;
+    top: 10rem;
+}
+
+.home .controls .vid-btn {
+    height: 2rem;
+    width: 2rem;
+    display: inline-block;
+    border-radius: 50%;
+    background: #fff;
+    cursor: pointer;
+    margin: 0 .5rem;
+}
+
+.home .controls .vid-btn.active {
+    background: #4981b2;
+}
+
+/* 底部 */
+.footer {
+    background: #333;
+}
+
+.footer .box-container {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 1rem;
+}
+
+.footer .box-container .box {
+    padding: 1rem 0;
+    flex: 1 1 12rem;
+}
+
+.footer .box-container .box h3 {
+    font-size: 1.5rem;
+    padding: .5rem 0;
+    color: #fff;
+}
+
+.footer .box-container .box p {
+    font-size: 1.0rem;
+    padding: .5rem 0;
+    color: #eee;
+}
+
+.footer .box-container .box a {
+    display: block;
+    font-size: 1rem;
+    padding: .5rem 0;
+    color: #eee;
+}
+
+.footer .box-container .box a:hover {
+    color: #ffa500;
+    text-decoration: underline;
+}
+
+.footer .credit {
+    text-align: center;
+    padding: 1rem 0.5rem;
+    margin-top: 0.5rem;
+    font-size: 1rem;
+    font-weight: normal;
+    color: #fff;
+    border-top: .1rem solid rgba(255, 255, 255, .2);
+}
+
+.footer .credit span {
+    color: #ffa500;
+}
+
+/* 设配多端 */
+#menu-bar {
+    color: #fff;
+    border: .1rem solid #fff;
+    border-radius: .5rem;
+    font-size: 1.5rem;
+    padding: .5rem 1rem;
+    cursor: pointer;
+    display: none;
+}
+
+@media (max-width:1200px) {
+
+    html {
+        font-size: 80%;
+    }
+
+}
+
+@media (max-width:768px) {
+
+    #menu-bar {
+        display: initial;
+    }
+
+    header .navbar {
+        position: absolute;
+        top: -1000%;
+        right: 0;
+        left: 0;
+        background: #333;
+        border-top: .1rem solid rgba(255, 255, 255, .2);
+        padding: 1rem 1.5rem;
+    }
+
+    header .navbar.active {
+        top: 100%;
+    }
+
+    header .navbar a {
+        display: block;
+        border-radius: .5rem;
+        padding: 1rem;
+        margin: 1rem 0;
+        background: #222;
+    }
+
+}
+
+@media (max-width:450px) {
+
+    html {
+        font-size: 60%;
+    }
+
+    .footer .box-container .box {
+        flex: 1 1 18rem;
+        padding: 1rem 0;
+        text-align: center;
+    }
+
+}
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