/* ================== FIX TOÀN MÀN HÌNH SIÊU ĐẸP NHƯ ẢNH BẠN MUỐN ================== */
#header{
    width: 100%;
    height: 90px;
    background-color: #282a37;
    /* position: absolute; */
    
}
#top-header{
    width: 100%;
    height: 60%;
    /* border: 1px solid yellow; */

}
.logo{
    width: 25%;
    height: 100%;
    /* border: 1px solid red; */
   float: left;
}
.logo img{
    width: 200px;
    margin-left: 100px;
    margin-top: 10px;

}  
#search{
    width: 40%;
    height: 100%;
    /* border: 1px solid green; */
    float: left;
}
.search-text{
    margin-top: 20px;
    width: 500px;
    height: 30px;
    
}
.btn-search{
    margin-top: 20px;
    width: 50px;
    height: 30px;
    /* border-radius: 20%; */
}
#user{
    width: 35%;
    height: 100%;
    /* border: 1px solid tomato; */
    float: left;
}
.account{
    float: left;
    width: 35%;
    height: auto;
    /* border: 1px solid red; */
    
}
/* .account{  
        width: 0; height: 0; 
        border: 100px solid;
        border-bottom-color: blue;
} */
#icon-user i{
    font-size: 25px;
    color: white;
    margin-top: 20px;
    float: left;
}
.account ul li{
    list-style: none;
}
.account a{
    text-decoration: none;
    /* line-height: 0px; */
}
.sign-up{
    padding-top: 20px;
    /* padding-left: 10px; */
    /* border: 1px solid green; */
    color: white;
    padding-left:30px;

}
.sign-up span{
    color: white;
    font-size: 70%;
    font-weight: 400;
}


ul.user2{
    position: absolute;
    background-color:aqua;
    z-index:9999;
    width: 255px;
    border-radius: 10px;

    
} 


ul.user2 li{
    padding: 15px 0 10px 0 ;
	float: none;
	display: none;
    margin-left: 10px;
    margin-right: 10px;
   
}
.user2{
    list-style: none;
    
}

.user2 li{
    margin-top: 5px;
}
.account ul li:hover ul.user2 li{
	/* hiện */
    display: block;
}
.dn{
    background-color: yellow;
    text-align: center;
    border-radius: 20px; 
    line-height: 20px;
    
}
.ttk{
    background-color: yellow;
    text-align: center;
    border-radius: 20px; 
}
.fb{
    background-color: #0066FF;
    text-align: center;
    border-radius: 20px;
    color: white;
}
.gmail{
    background-color: CC0000;
    text-align: center;
    border-radius: 20px;
    color: white;
}
.zalo{
    background-color: #3366FF;
    text-align: center;
    border-radius: 20px;
    color: white;
    margin-bottom: 5px;
}
.zalo img{
    width: 12%;
    height: 20px;
    /* font-size: 20px; */
    margin-right: 10px;
}
/* giỏ hàng */
.cart{
    float: left;
    margin-left: 10px;
}
.cart a{
    text-decoration: none;
    color: white;
    font-size: 15px;
    /* padding-left:30px;  */
}
.cart a i{

    font-size: 25px;
    color: white;
    margin-top: 20px;   
}
.cart-amount{
	background-color: #FFC125;
	color: #000;
	position: absolute;
	top: 16px;
	right: 300px;
	height: 20px;
	width: 20px;
	border-radius: 10px;
	font-size: 14px;
	line-height: 20px;
    cursor: pointer;
    text-align: center;
}
@media only screen and (min-width: 768px) {
    body {
        padding-top: 185px !important;
        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%) !important;
        min-height: 100vh;
    }

    /* Form login  */
   /* Khối form đăng nhập  */
#login {
  width: 450px;         
  max-width: 90%;
  margin: 60px auto;    
  padding: 30px 35px 28px;
  background: #ffffff;
  border-radius: 18px;
  box-shadow: 0 14px 35px rgba(0,0,0,0.18);
  text-align: center;
}

/* Tiêu đề */
#login h1 {
  margin-bottom: 22px;
  font-size: 24px;
  letter-spacing: 1px;
  color: #8b4513;
}

/* Nhóm input */
.input-box {
  width: 100%;
  margin-bottom: 14px;
  position: relative;
}

.input-box i {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: #999;
}

/* Ô input full chiều rộng */
.input-box input {
  width: 100%;
  padding: 11px 16px 11px 38px;
  border-radius: 999px;
  border: 1px solid #ddd;
  font-size: 14px;
  outline: none;
  box-sizing: border-box;
}

.input-box input:focus {
  border-color: #ff7b54;
  box-shadow: 0 0 0 2px rgba(255,123,84,0.2);
}

/* Nút Đăng nhập  */
.btn-login {
  width: 100%;
  border: none;
  border-radius: 999px;
  padding: 11px 0;
  margin-top: 8px;
  font-size: 15px;
  font-weight: 600;
  color: #fff;
  background: linear-gradient(135deg,#ff7b54,#ff416c);
  cursor: pointer;
  box-shadow: 0 10px 25px rgba(255,65,108,0.35);
  transition: all 0.25s;
}

.btn-login:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 32px rgba(255,65,108,0.55);
}

    /* Dropdown đăng nhập giữ nguyên  */
    .user2 {
        border-radius: 20px !important;
        overflow: hidden !important;
        box-shadow: 0 15px 40px rgba(0,0,0,0.3) !important;
    }
    .dn, .ttk {background: #ffd60a !important; color: black !important; font-weight: bold !important;}
    .fb {background: #1877f2 !important;}
    .gmail {background: #db4437 !important;}
    .zalo {background: #0068ff !important;}
}
#admin-link {
    color: yellow !important;
    font-weight: bold;
    animation: glow 2s infinite alternate;
}
@keyframes glow {
    from { text-shadow: 0 0 5px yellow; }
    to { text-shadow: 0 0 20px gold, 0 0 30px orange; }
}
<style>
    *{margin:0;padding:0;box-sizing:border-box;}
    body{background:#f0f2f5;font-family:Arial,sans-serif;}
    .admin-wrapper{display:flex;min-height:100vh;}
    .sidebar-admin{width:280px;background:#2c3e50;color:white;position:fixed;height:100%;overflow-y:auto;padding:30px 0;z-index:999;}
    .sidebar-admin h3{text-align:center;color:#1abc9c;font-size:26px;margin-bottom:50px;}
    .sidebar-admin a{display:block;padding:18px 35px;color:#bdc3c7;text-decoration:none;font-size:16px;border-left:4px solid transparent;transition:0.3s;}
    .sidebar-admin a:hover,.sidebar a.active{background:#34495e;border-left-color:#1abc9c;color:white;}
    .sidebar-admin a i{margin-right:15px;width:25px;text-align:center;}
    .header-admin{background:white;padding:18px 30px;box-shadow:0 3px 15px rgba(0,0,0,0.1);margin-left:280px;display:flex;justify-content:space-between;align-items:center;position:sticky;top:0;z-index:99;}
    .main-content{margin-left:280px;padding:30px;width:100%;}
    .content{background:white;border-radius:18px;padding:40px 35px;box-shadow:0 15px 40px rgba(0,0,0,0.1);}
    .stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:25px;margin:40px 0;}
    .card{background:linear-gradient(135deg,#667eea,#764ba2);color:white;padding:40px;border-radius:22px;text-align:center;box-shadow:0 15px 40px rgba(102,94,234,.5);transition:0.3s;}
    .card:hover{transform:translateY(-12px);}
    .card h3{font-size:55px;margin:10px 0;font-weight:bold;}
    table{width:100%;border-collapse:collapse;margin-top:30px;border-radius:15px;overflow:hidden;box-shadow:0 8px 30px rgba(0,0,0,0.12);}
    th{background:#667eea;color:white;padding:22px;font-size:17px;}
    td{padding:18px;text-align:center;border-bottom:1px solid #eee;font-size:15px;}
    .btn{padding:11px 22px;border:none;border-radius:10px;color:white;font-weight:bold;cursor:pointer;margin:0 6px;transition:0.3s;}
    .btn-add{background:#27ae60;font-size:18px;padding:15px 35px;}
    .btn-sua{background:#f39c12;}
    .btn-xoa{background:#e74c3c;}
    .btn:hover{opacity:0.9;transform:scale(1.08);}

    /* <<< THÊM 3 DÒNG NÀY VÀO ĐÂY – ĐẢM BẢO 100% HIỆN SIDEBAR + HEADER >>> */
    .sidebar-admin { position: fixed !important; left: 0 !important; top: 0 !important; z-index: 9999 !important; }
    .header-admin { position: sticky !important; top: 0 !important; z-index: 9998 !important; }
    .main-content, .header-admin { margin-left: 280px !important; }
</style>
/* ÉP BUỘC SIDEBAR + HEADER HIỆN ĐÚNG VỊ TRÍ - 100% KHÔNG BỊ ĐÈ */
.sidebar-admin { 
    position: fixed !important; 
    left: 0 !important; 
    top: 0 !important; 
    z-index: 9999 !important; 
}
.header-admin { 
    position: sticky !important; 
    top: 0 !important; 
    z-index: 9998 !important; 
}
.main-content, .header-admin { 
    margin-left: 280px !important; 
}