body {
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    background-color: #f0f4f8;
    margin: 0;
    padding: 0;
    color: #333;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

header {
    background: #fff;
    padding: 20px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    margin-bottom: 30px;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: #007bff;
    text-decoration: none;
}

.nav a {
    margin-left: 20px;
    text-decoration: none;
    color: #666;
    transition: color 0.3s;
}

.nav a:hover {
    color: #007bff;
}

.card {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    padding: 20px;
    margin-bottom: 20px;
    position: relative;
    overflow: hidden;
}

.notice {
    background: #e3f2fd;
    color: #0d47a1;
    padding: 15px;
    border-radius: 6px;
    margin-bottom: 20px;
    border-left: 4px solid #2196f3;
}

.category-title {
    font-size: 18px;
    font-weight: bold;
    margin-bottom: 15px;
    border-left: 4px solid #007bff;
    padding-left: 10px;
}

.product-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.product-item {
    background: #fff;
    border: 1px solid #eef2f5;
    border-radius: 6px;
    padding: 20px;
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
    text-decoration: none;
    color: inherit;
    display: block;
    position: relative;
    overflow: hidden;
}

.product-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    border-color: #007bff;
}

.hot-item {
    border: 1px solid #ffcccc;
    background: linear-gradient(to bottom right, #fff, #fff5f5);
}

.hot-item:hover {
    border-color: #dc3545;
    box-shadow: 0 5px 15px rgba(220, 53, 69, 0.15);
}

.recommend-item {
    border: 1px solid #ffeeba;
    background: linear-gradient(to bottom right, #fff, #fffbf0);
}

.recommend-item:hover {
    border-color: #ffc107;
    box-shadow: 0 5px 15px rgba(255, 193, 7, 0.2);
}

/* Ribbon Styles */
.ribbon {
    position: absolute;
    right: -5px;
    top: -5px;
    z-index: 1;
    overflow: hidden;
    width: 75px;
    height: 75px;
    text-align: right;
}

.ribbon span {
    font-size: 10px;
    font-weight: bold;
    color: #FFF;
    text-transform: uppercase;
    text-align: center;
    line-height: 20px;
    transform: rotate(45deg);
    -webkit-transform: rotate(45deg);
    width: 100px;
    display: block;
    background: #79A70A;
    background: linear-gradient(#9BC90D 0%, #79A70A 100%);
    box-shadow: 0 3px 10px -5px rgba(0, 0, 0, 1);
    position: absolute;
    top: 19px;
    right: -21px;
}

.ribbon-hot span {
    background: linear-gradient(#ff6b6b 0%, #ee5253 100%);
}

.ribbon-recommend span {
    background: linear-gradient(#feca57 0%, #ff9f43 100%);
}

.product-name {
    font-size: 16px;
    font-weight: bold;
    margin-bottom: 10px;
    color: #333;
}

.product-price {
    color: #ff5722;
    font-weight: bold;
    font-size: 18px;
}

.stock {
    font-size: 12px;
    color: #999;
    margin-top: 5px;
}

.footer {
    text-align: center;
    padding: 30px 0;
    color: #999;
    font-size: 12px;
}

/* Form Styles */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #555;
}

.form-control {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box;
    font-size: 14px;
    transition: border-color 0.3s;
    outline: none;
}

.form-control:focus {
    border-color: #007bff;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    background: #007bff;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    text-decoration: none;
    transition: background 0.3s;
    text-align: center;
}

.btn:hover {
    background: #0056b3;
}

.btn-block {
    display: block;
    width: 100%;
}

.btn-sm {
    padding: 5px 10px;
    font-size: 12px;
}

/* Input Group with Icons */
.input-group {
    position: relative;
}

.input-group i {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: #aaa;
    pointer-events: none;
}

.input-group .form-control {
    padding-left: 40px;
}

.input-group .form-control:focus + i {
    color: #007bff;
}