/* Progressive teaching, retaining the teacher's words and mathematical working. */
.ex-solution-tools{display:flex;justify-content:space-between;align-items:center;gap:14px;margin:22px 0 12px;color:#173b57;font-size:14px;font-weight:700}.ex-expand-all{appearance:none;border:1px solid #b9cfe0;border-radius:7px;padding:8px 13px;background:#fff;color:#086ec8;font:inherit;cursor:pointer}.ex-expand-all[hidden]{display:none}.ex-expand-all:hover{background:#edf5fc}.ex-part{border:1px solid #d9e4ed;border-radius:10px;background:#fff;margin:10px 0;min-width:0}.ex-part>summary{cursor:pointer;padding:15px 18px;color:#173b57;font-size:17px;line-height:1.6;font-weight:700}.ex-part>summary::marker{color:#0872cc}.ex-part[open]>summary{border-bottom:1px solid #e4ecf3}.ex-part-body{padding:6px 18px 15px;min-width:0}.ex-progressive .ex-source-block:empty{display:none}.ex-progressive p{margin:8px 0}.ex-progressive li{margin:6px 0}.ex-progressive .katex-display{margin:7px 0;padding:5px 3px}.ex-part .ex-source-block h3{font-size:17px;margin:14px 0 8px}.ex-verify{background:#f5f8fb}.ex-verify>summary{font-size:15px}.ex-verify blockquote{margin:8px 0}.ex-followup.ex-practice{padding:0;border:1px solid #d9e4ed;background:#f5f8fb;margin-top:18px}.ex-practice>summary{padding:16px 18px;color:#173b57;font-size:16px;font-weight:700;cursor:pointer}.ex-practice-body{padding:0 18px 18px;min-width:0}.ex-practice-body>details{margin-top:15px;border-top:1px solid #d9e4ed;padding-top:10px}.ex-practice-body>details>summary{padding:6px 0}.ex-expand-all:focus-visible,.ex-part>summary:focus-visible,.ex-practice>summary:focus-visible{outline:3px solid #d8a33e;outline-offset:3px}#em-statistics .ex-wide-figure{max-width:620px;background:#fff}#em-statistics .ex-wide-figure>img{max-width:600px}
@media(max-width:760px){.ex-solution-tools{margin-top:18px;font-size:13px}.ex-part>summary{padding:13px 14px;font-size:16px}.ex-part-body{padding:4px 14px 13px}.ex-verify>summary{font-size:15px}.ex-practice>summary{padding:14px}.ex-practice-body{padding:0 14px 14px}.ex-progressive .katex-display{margin:6px 0;padding:5px 2px}}