body {
    font-family: Arial, sans-serif;
    background: #f6f9fa;
    margin: 0;
    padding: 0;
}
header {
    background: #1877c2;
    color: #fff;
    padding: 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
header h1 {
    margin: 0;
    font-size: 1.6em;
}
.user-info {
    font-size: 1em;
}
.logout {
    color: #fff;
    text-decoration: underline;
    margin-left: 16px;
}
nav {
    background: #eee;
    padding: 0 0 0 15px;
}
nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}
nav ul li {
    margin: 0 15px 0 0;
}
nav ul li a {
    color: #1877c2;
    text-decoration: none;
    padding: 8px 0;
    display: block;
}
nav ul li a:hover, nav ul li.active a {
    font-weight: bold;
    border-bottom: 2px solid #1877c2;
}
.login-container {
    max-width: 340px;
    margin: 70px auto;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 12px #1877c266;
    padding: 24px;
}
.login-container h2 {
    text-align: center;
    margin-bottom: 24px;
}
.login-container form label {
    display: block;
    margin-top: 10px;
    color: #1877c2;
}
.login-container input[type="text"], .login-container input[type="password"] {
    width: 100%;
    padding: 8px;
    margin-top: 2px;
    margin-bottom: 10px;
    border-radius: 4px;
    border: 1px solid #1877c2;
    font-size: 1em;
}
.login-container button {
    width: 100%;
    background: #1877c2;
    color: #fff;
    border: none;
    padding: 10px 0;
    border-radius: 4px;
    font-size: 1.1em;
    cursor: pointer;
}
.error {
    color: #fff;
    background: #f05c3c;
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 10px;
    text-align: center;
}
.success {
    color: #155724;
    background: #d4edda;
    padding: 10px;
    border-radius: 4px;
    margin-bottom: 10px;
    text-align: center;
}
main {
    max-width: 1100px;
    margin: 30px auto;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 12px #1877c266;
    padding: 24px;
}
.form-section {
    background: #f6f9fa;
    padding: 14px 18px;
    border-radius: 8px;
    margin-bottom: 28px;
}
.form-section form label {
    font-weight: bold;
}
.form-section input, .form-section textarea, .form-section select {
    width: 100%;
    margin-top: 4px;
    margin-bottom: 8px;
    padding: 8px;
    border-radius: 4px;
    border: 1px solid #bbb;
    font-size: 1em;
}
.form-section textarea {
    height: 60px;
    resize: vertical;
}
.form-section button {
    background: #1877c2;
    color: #fff;
    border: none;
    border-radius: 4px;
    padding: 10px 24px;
    font-size: 1.1em;
    cursor: pointer;
}
.form-section a {
    margin-left: 20px;
    color: #1877c2;
    text-decoration: underline;
}
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
}
table thead {
    background: #e3eaf0;
}
table th, table td {
    padding: 8px 10px;
    border: 1px solid #d0dbe7;
    text-align: left;
}
table tbody tr:nth-child(even) {
    background: #f6f9fa;
}
table tbody tr:hover {
    background: #d3e6f9;
}
@media (max-width: 900px) {
    main {
        max-width: 99vw;
        padding: 10px;
    }
    table, thead, tbody, th, td, tr {
        display: block;
    }
    table thead {
        display: none;
    }
    table td {
        position: relative;
        padding-left: 50%;
        margin-bottom: 8px;
        border: none;
        border-bottom: 1px solid #ddd;
    }
    table td:before {
        position: absolute;
        left: 10px;
        width: 45%;
        white-space: nowrap;
        content: attr(data-label);
        font-weight: bold;
        color: #1877c2;
    }
}