/**
 * 段落排序题方框链重绘层
 *
 * 全部尺寸用 % (页面相对) + em (相对重绘层字号 = 12pt 等效 px)，
 * 缩放由 #pdf-viewer 的 transform 自动等比，恒比不漂移。
 * 层级：页图(0) < 单词区(2) < 本层(5) < 答案预览 ink(15) < 题号热区(20)，
 * 热区重定位到新框上，已答色/halo 沿用标准 .qs-answered。
 */
.paragraph-chain-overlay {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 5;
    font-family: 'Times New Roman', 'Nimbus Roman', Times, serif;
    color: #000;
}

.paragraph-chain-overlay .pco-mask {
    position: absolute;
    background: #fff;
}

.paragraph-chain-overlay .pco-box {
    position: absolute;
    box-sizing: border-box;
    /* 0.06em ≈ 印刷 0.7pt 线宽；直角无圆角(硬规范) */
    border: 0.06em solid #000;
    border-radius: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.paragraph-chain-overlay .pco-box--question {
    column-gap: 0.40em;
}

.paragraph-chain-overlay .pco-num,
.paragraph-chain-overlay .pco-letter {
    font-size: 1em;
    line-height: 1;
    /* 光学下移补偿：数字/字母视觉重心偏高 */
    transform: translateY(0.09em);
}

/* 固定预留答案槽：已答/未答框内题号位置完全一致(硬规范) */
.paragraph-chain-overlay .pco-slot {
    width: 0.66em;
    align-self: stretch;
}

.paragraph-chain-overlay .pco-arrow {
    position: absolute;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1667em; /* 14pt / 12pt */
    line-height: 1;
}

/* 入槽的答案 ink：去 letter-spacing 防单字母右偏 */
.question-answer-preview.pco-in-slot .question-answer-preview-ink {
    letter-spacing: 0 !important;
}