:root{--bg:#f5f6f8;--card:#fff;--text:#1b2130;--muted:#667085;--line:#e6e8ec;--primary:#3b5bdb;--primary-weak:#eaf0ff;--correct:#2f9e44;--correct-weak:#e6f6ea;--wrong:#e03131;--wrong-weak:#fdecec;--radius:16px}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}html{-webkit-text-size-adjust:100%}body,html{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Apple SD Gothic Neo,Pretendard,Segoe UI,Roboto,Noto Sans KR,sans-serif;font-size:17px;line-height:1.7;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}.container{width:100%;max-width:720px;margin:0 auto;padding:18px 16px 96px}.site-header{position:-webkit-sticky;position:sticky;top:0;z-index:10;background:hsla(0,0%,100%,.92);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}.site-header .inner{max-width:720px;margin:0 auto;padding:14px 16px;display:flex;align-items:center;gap:12px}.site-header .brand{font-weight:800;font-size:18px}.site-header .spacer{flex:1 1}.site-header nav a{font-size:15px;color:var(--muted);padding:8px 12px;border-radius:10px}h1{font-size:24px;margin:6px 0 4px;line-height:1.35}.page-sub{color:var(--muted);margin:0 0 20px;font-size:15px}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px 16px;margin-bottom:14px}.set-list{display:grid;grid-gap:14px;gap:14px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:1.5px solid var(--line);background:#fff;color:var(--text);padding:12px 18px;border-radius:12px;font-size:16px;font-weight:700;cursor:pointer;transition:all .12s ease;min-height:46px}.btn:active{transform:scale(.98)}.btn.primary{background:var(--primary);color:#fff;border-color:var(--primary)}.btn.ghost{background:transparent;border-color:transparent;color:var(--muted)}.btn:disabled{opacity:.45;cursor:default}.btn-sm{padding:10px 14px;font-size:15px;min-height:42px}.q-head{display:flex;align-items:center;gap:10px;margin-bottom:12px;flex-wrap:wrap}.q-num{font-weight:800;color:var(--primary);font-size:16px}.q-flag{font-size:12.5px;color:var(--wrong);border:1px solid var(--wrong-weak);background:var(--wrong-weak);padding:2px 9px;border-radius:999px}.q-text{font-size:18px;font-weight:600;margin:0 0 16px;white-space:pre-wrap;line-height:1.6}.q-code{background:#0f172a;color:#e2e8f0;padding:14px;border-radius:12px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:14px;overflow-x:auto;margin:0 0 16px;white-space:pre;-webkit-overflow-scrolling:touch}.choices{display:grid;grid-gap:10px;gap:10px}.choice{display:flex;align-items:flex-start;gap:12px;text-align:left;border:1.5px solid var(--line);background:#fff;border-radius:12px;padding:14px;font-size:16.5px;cursor:pointer;width:100%;transition:all .1s ease;line-height:1.5;color:var(--text)}.choice:active:not(:disabled){transform:scale(.99)}.choice:disabled{cursor:default}.choice .no{flex:none;width:26px;height:26px;border-radius:50%;border:1.5px solid var(--line);display:inline-flex;align-items:center;justify-content:center;font-size:13px;font-weight:800;color:var(--muted);margin-top:1px}.choice.correct{border-color:var(--correct);background:var(--correct-weak)}.choice.correct .no{border-color:var(--correct);background:var(--correct);color:#fff}.choice.wrong{border-color:var(--wrong);background:var(--wrong-weak)}.choice.wrong .no{border-color:var(--wrong);background:var(--wrong);color:#fff}.choice.picked{box-shadow:0 0 0 3px rgba(59,91,219,.16)}.explain{margin-top:16px;border-top:1px dashed var(--line);padding-top:16px}.explain .verdict{font-weight:800;font-size:16.5px;margin-bottom:12px}.explain .verdict.o{color:var(--correct)}.explain .verdict.x{color:var(--wrong)}.explain h4{margin:14px 0 6px;font-size:14.5px;color:var(--muted);font-weight:700}.explain p{margin:0 0 8px;font-size:16px}.explain .ex-choices{display:grid;grid-gap:7px;gap:7px}.explain .ex-choice{font-size:15.5px;padding:11px 12px;border-radius:10px;background:var(--bg);line-height:1.55}.explain .ex-choice.ans{background:var(--correct-weak)}.explain .summary{background:var(--primary-weak);color:#24325f;padding:12px 14px;border-radius:12px;font-size:15.5px}.tags{margin-top:14px;display:flex;flex-wrap:wrap;gap:7px}.tag{font-size:13px;color:var(--muted);background:var(--bg);border:1px solid var(--line);padding:3px 11px;border-radius:999px}.toolbar{display:flex;align-items:center;gap:12px;margin-bottom:18px;flex-wrap:wrap}.progress{height:10px;background:var(--line);border-radius:999px;overflow:hidden;flex:1 1;min-width:130px}.progress>span{display:block;height:100%;background:var(--primary);transition:width .25s ease}.stat{font-size:14.5px;color:var(--muted)}.stat b{color:var(--text)}.filter-row{display:flex;gap:8px;margin-bottom:18px;overflow-x:auto;padding-bottom:4px;-webkit-overflow-scrolling:touch}.filter-row::-webkit-scrollbar{display:none}.chip{flex:none;font-size:15px;padding:10px 16px;border-radius:999px;border:1.5px solid var(--line);background:#fff;cursor:pointer;font-weight:600;min-height:42px}.chip.active{background:var(--primary);color:#fff;border-color:var(--primary)}.empty{text-align:center;color:var(--muted);padding:44px 12px}.footer-nav{position:-webkit-sticky;position:sticky;bottom:0;display:flex;gap:10px;align-items:center;margin-top:18px;padding:12px 0 6px;background:linear-gradient(transparent,var(--bg) 30%)}.footer-nav .btn{flex:1 1}.footer-nav .pageno{flex:none;font-size:14.5px;color:var(--muted);min-width:58px;text-align:center}@media (min-width:720px){body{font-size:17px}h1{font-size:28px}}