body,html{margin:0;padding:0;font-family:Arial,sans-serif}.main-header{background:#fff;box-shadow:0 2px 5px rgba(0,0,0,0.1)}.header-top{max-width:1200px;margin:0 auto;padding:20px;display:flex;justify-content:space-between;align-items:center}.logo img{height:40px}.search-box input{padding:8px 15px;width:300px;border:1px solid #dadada;border-radius:4px;font-size:14px}.search-box input::placeholder{color:#999}.main-nav{border-top:1px solid #dadada;background:#f8f8f8}.main-nav ul{max-width:1200px;margin:0 auto;padding:0;list-style:none;display:flex;justify-content:center}.main-nav li{margin:0 20px}.main-nav a{display:block;padding:15px 0;color:#333;text-decoration:none;font-size:16px;transition:color .3s}.main-nav a:hover{color:#3b6a7c}body{background-color:#f5f5f5}.content-container{max-width:720px;margin:40px auto;padding:30px 40px;background-color:#fff;color:#000;box-shadow:0 2px 5px rgba(0,0,0,0.1)}.content-container h1{font-size:32px;margin-bottom:20px}.content-container h2{font-size:28px;margin-bottom:30px}.content-container p{margin-bottom:20px;line-height:1.8;font-size:18px}.center{display:flex;justify-content:center;align-items:center;text-align:center}.center p{margin-top:10px;margin-bottom:10px}.red{color:red;font-weight:bold;font-size:28px}.burger-menu{display:none}@media screen and (max-width:768px){.header-top{flex-direction:column;align-items:center;padding:10px;position:relative}.search-box{display:none}.burger-menu{display:block;top:20px;right:20px;cursor:pointer}.burger-menu span{display:block;width:25px;height:3px;margin:5px 0;background-color:#333;transition:all .3s ease}.main-nav{display:none;width:100%}.main-nav ul{flex-direction:column;align-items:center}.main-nav li{margin:10px 0}}@media screen and (max-width:450px){p{font-size:22px}}