* {
    box-sizing: border-box;
}
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #f2f4f8;
    color: #22303c;
}
.wrapper {
    max-width: 960px;
    margin: 0 auto;
    padding: 24px;
}
header {
    text-align: center;
    padding: 32px 16px;
    background: linear-gradient(135deg, #4b6cb7, #182848);
    color: white;
    border-radius: 16px;
}
header h1 {
    margin: 0;
    font-size: 2.2rem;
}
header p {
    margin: 12px 0 0;
    opacity: 0.9;
}
nav {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin: 24px 0;
}
nav a {
    text-decoration: none;
    color: #4b6cb7;
    font-weight: 600;
}
.panel {
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 18px 40px rgba(14, 30, 37, 0.08);
    margin-bottom: 24px;
}
.panel h2 {
    margin-top: 0;
}
form {
    display: grid;
    gap: 12px;
}
input[type="file"] {
    padding: 10px;
}
button {
    width: fit-content;
    padding: 12px 24px;
    border: none;
    border-radius: 999px;
    background: #4b6cb7;
    color: white;
    font-size: 1rem;
    cursor: pointer;
}
button:hover {
    background: #3a56a1;
}
.message {
    margin-bottom: 16px;
    padding: 14px 16px;
    border-radius: 12px;
    background: #e7f3ff;
    color: #0f3d7a;
    border: 1px solid #d3e6ff;
}
.hint {
    color: #5d6875;
    margin: 0;
}
table {
    width: 100%;
    border-collapse: collapse;
}
th, td {
    text-align: left;
    padding: 14px 12px;
    border-bottom: 1px solid #ebeff4;
}
th {
    color: #5c6a79;
}
footer {
    text-align: center;
    color: #7a8a99;
    padding: 16px 0;
}
@media (max-width: 720px) {
    nav {
        flex-direction: column;
    }
    th, td {
        display: block;
        width: 100%;
    }
    tr {
        margin-bottom: 16px;
        display: block;
    }
}