body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Arial, 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    margin: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

header h1 { margin: 0 0 12px; }
nav a { margin-right: 12px; text-decoration: none; }
.card { background: #fff; padding: 16px; border: 1px solid #e5e7eb; border-radius: 12px; box-shadow: 0 1px 3px rgba(0,0,0,.06); }
button { padding: 8px 14px; border: 1px solid #2563eb; background: #3b82f6; color: #fff; border-radius: 8px; cursor: pointer; }
button:hover { opacity: .9; }
.table-wrapper { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; }
th, td { border: 1px solid #eee; padding: 8px; text-align: left; }
.error { margin-top: 12px; color: #b91c1c; }

.citation-instruction {
    font-family: 'Times New Roman', sans-serif !important;
    font-size: 24px !important;
    font-weight: bold !important;
    text-align: left;
    width: 100%;
    margin-top: 40px;
    margin-bottom: 20px;
}

.citation-box {
    width: 100%;
    height: 225px;
    background: #fff;
    padding: 12px;
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0,0,0,.06);
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    box-sizing: border-box;
}

.citation-title {
    font-family: 'Times New Roman', serif !important;
    font-size: 24px !important;
    font-weight: bold !important;
    text-align: left;
    margin-top: 0px;
    margin-bottom: 0px;
    line-height: 1;
}

.citation-reference {
    font-family: 'Times New Roman', serif !important;
    font-size: 20px !important;
    font-weight: normal !important;
    text-align: justify;
    margin-bottom: 0px;
    line-height: 1.5;
}
.citation-reference .journal-name {
    font-style: italic;
}

.citation-paper-label {
    font-family: 'Times New Roman', serif !important;
    font-size: 24px !important;
    font-weight: bold !important;
    text-align: left;
    margin-bottom: 18px;
    line-height: 1;
}

.citation-link {
    color: #3b82f6 !important;
    font-weight: normal !important;
    text-decoration: none;
    font-family: 'Times New Roman', serif !important;
    font-size: 20px !important;
    text-align: left;
    text-decoration: none;
    line-height: 1.5;
}
.citation-link:hover {
    color: #2563eb !important;
    text-decoration: underline;
}
.citation-link:visited {
    color: #3b82f6 !important;
}

main:not(.download-main) {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}