* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: #f5f7fb;
    color: #1f2937;
}

.container {
    max-width: 880px;
    margin: 32px auto;
    padding: 0 16px 32px;
}

.card {
    background: #ffffff;
    border: 1px solid #dbe3ef;
    border-radius: 14px;
    padding: 20px;
    margin-bottom: 18px;
    box-shadow: 0 6px 20px rgba(15, 23, 42, 0.06);
}

h1, h2, h3 { margin-top: 0; }

.subhead, .hint, .meta {
    color: #5b6577;
}

.stack > div { margin-bottom: 16px; }

label {
    display: block;
    font-weight: 700;
    margin-bottom: 8px;
}

input[type="text"], textarea, input[type="file"] {
    width: 100%;
    border: 1px solid #c9d4e5;
    border-radius: 10px;
    padding: 12px;
    font-size: 16px;
    background: #fff;
}

textarea {
    resize: vertical;
    min-height: 160px;
}

button {
    border: 0;
    background: #1f4fd1;
    color: #fff;
    padding: 12px 18px;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
}

button:hover { opacity: 0.95; }

.warning {
    border-color: #f0c36d;
    background: #fff8e8;
}

.response-block {
    margin-top: 18px;
    padding-top: 14px;
    border-top: 1px solid #e5ebf5;
}

.answer {
    white-space: pre-wrap;
    line-height: 1.5;
}

.note {
    background: #f8fbff;
    border: 1px solid #d9e7ff;
    border-radius: 10px;
    padding: 12px;
}

ul {
    margin: 0;
    padding-left: 20px;
}