body[data-page='archive'] .page-hero { display: none; }
body[data-page='archive'] .page-section { padding-top: 32px; }
#archive-app { min-width: 0; }
.archive-intro { max-width: 880px; margin-bottom: 30px; position: static; }
.archive-kicker { margin: 0 0 12px; color: #6b799a; font-size: 10px; line-height: 1.6; font-weight: 600; letter-spacing: .09em; text-transform: uppercase; }
.archive-intro h1,.archive-problem-heading h1,.archive-missing-title { margin: 0 0 18px; color: var(--blue-night); font: 600 clamp(34px,4.5vw,52px)/1.2 var(--display); letter-spacing: -.035em; }
.archive-intro > p.archive-lead { max-width: 720px; color: var(--muted); font-size: 16px; line-height: 1.9; margin: 0 0 22px; }
.archive-intro > p.archive-stats { max-width: none; display: flex; align-items: baseline; flex-wrap: wrap; gap: 10px; margin: 0; color: #778ba5; font-size: 12px; }
.archive-stats strong { color: #365992; font-size: 28px; font-weight: 500; }
.archive-stats-path { border-left: 1px solid #dce4ef; margin-left: 10px; padding-left: 20px; }
.archive-filters { padding: 24px; border: 1px solid #dce4ef; border-radius: 12px; background: #f6f8fc; display: grid; gap: 18px; }
.archive-filter-heading { display: flex; justify-content: space-between; align-items: baseline; gap: 20px; }
.archive-filter-heading h2 { color: var(--blue-night); font: 600 19px var(--display); margin: 0; flex: none; }
.archive-filter-heading p { margin: 0; color: #7a8da5; font-size: 12px; line-height: 1.7; }
.archive-search { display: block; position: relative; }
.archive-search::before { content: ''; position: absolute; left: 15px; top: 16px; width: 18px; height: 18px; background: #8093b0; mask: url('assets/search.svg') center/contain no-repeat; }
.archive-search input { width: 100%; min-height: 50px; padding: 12px 14px 12px 44px; border: 1px solid #d3dfea; border-radius: 7px; background: #fff; color: var(--blue-night); font: 400 15px var(--display); }
.archive-selects { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 16px; }
.archive-selects label { display: grid; gap: 7px; min-width: 0; color: #6d819f; font-size: 11px; }
.archive-selects select { width: 100%; min-width: 0; min-height: 46px; padding: 10px; border: 1px solid #d3deec; border-radius: 6px; background: #fff; color: #29466d; font: 400 14px var(--display); }
.archive-results-heading { display: flex; justify-content: space-between; align-items: baseline; gap: 20px; margin: 34px 0 18px; scroll-margin-top: 110px; outline: none; }
.archive-results-heading h2 { font: 600 25px var(--display); margin: 0; color: var(--blue-night); }
.archive-results-heading p { font-size: 12px; color: #7b8ea8; margin: 0; }
.archive-problem-list { border-top: 1px solid #dce5ef; }
.archive-card { display: grid; grid-template-columns: 45px minmax(0,1fr) 150px; align-items: center; gap: 22px; padding: 24px 12px; border-bottom: 1px solid #e2e8f1; color: inherit; transition: background .15s; }
.archive-card:hover { background: #f7f9fd; }
.archive-card-number { font-size: 12px; color: #a0adbf; align-self: start; padding-top: 4px; }
.archive-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 12px; color: #7086a4; font-size: 11px; line-height: 1.6; }
.archive-meta > span + span { position: relative; }
.archive-difficulty { padding: 3px 8px; border-radius: 4px; background: #eef3fb; color: #5176a5; }
.archive-difficulty.difficulty-2 { background: #eff5f2; color: #507e69; }.archive-difficulty.difficulty-3 { background: #fbf3e6; color: #9d7a44; }
.archive-proof-tag { font-size: 10px; border: 1px solid #dfe4ed; padding: 2px 7px; border-radius: 4px; color: #8491a5; }
.archive-card h3 { margin: 10px 0 8px; font: 600 21px/1.4 var(--display); color: #223f67; }
.archive-card-body > p { margin: 0; font-size: 14px; line-height: 1.85; color: #6d809b; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.archive-card-action { font-size: 12px; font-weight: 500; text-align: right; color: #416caa; }
.archive-solved { display: inline-block; margin-top: 8px; color: #39836b; font-size: 11px; }
.archive-button { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 10px 16px; border: 1px solid #cbd8e9; border-radius: 6px; background: #fff; color: #345a91; font: 500 13px/1.5 var(--display); cursor: pointer; }
.archive-button:hover { background: #edf3fc; }.archive-button:disabled { opacity: .4; cursor: default; }.archive-button.primary { color: #fff; background: #315a9c; border-color: #315a9c; }
.archive-pagination { display: flex; align-items: center; justify-content: center; gap: 20px; margin-top: 28px; }
.archive-pagination[hidden] { display: none; }.archive-pagination > span { color: #788aa3; font-size: 12px; }
.archive-origin { color: #93a0b2; font-size: 12px; line-height: 1.8; border-top: 1px solid #e5ebf2; padding-top: 22px; margin-top: 32px; }
.archive-empty { padding: 36px 20px; text-align: center; color: #768aa4; font-size: 15px; line-height: 1.8; }
.archive-topic-filter { margin: 0; display: flex; align-items: center; gap: 15px; color: #7b8da3; font-size: 12px; }
.archive-text-button { min-height: 44px; border: 0; background: none; color: #5277ad; text-decoration: underline; cursor: pointer; }
.archive-link { display: inline-flex; align-items: center; min-height: 44px; color: #456da5; font-size: 14px; line-height: 1.7; }
.archive-link:hover { text-decoration: underline; }
.archive-problem-heading { margin: 28px 0; max-width: 1000px; }
.archive-problem-heading .archive-meta { margin-bottom: 14px; }.archive-problem-heading h1 { margin-bottom: 0; }
.archive-reading-layout { display: grid; grid-template-columns: minmax(0,1fr) 320px; align-items: start; gap: 30px; }
.archive-reading-main,.archive-reading-aside { min-width: 0; }
.archive-question { border: 1px solid #d9e3f0; border-radius: 11px; background: #f8fafd; padding: 26px; margin-bottom: 24px; }
.archive-question h2 { margin: 0 0 14px; font: 600 21px var(--display); color: var(--blue-night); }
.archive-question > p { margin: 0; font-size: 18px; line-height: 1.95; color: #3e5879; }
.archive-diagram { margin: 22px 0 0; background: #fff; border: 1px solid #e3eaf3; border-radius: 8px; padding: 10px; }
.archive-diagram svg { display: block; width: 100%; height: auto; max-height: 250px; font-family: var(--display); }
.archive-solution { border: 1px solid #d9e3ee; border-radius: 10px; background: #fff; scroll-margin-top: 110px; }
.archive-solution > summary { padding: 20px 24px; min-height: 58px; cursor: pointer; color: #345e96; font-size: 16px; font-weight: 600; line-height: 1.7; }
.archive-solution[open] > summary { border-bottom: 1px solid #e7edf5; }
.archive-steps { margin: 0; padding: 4px 30px 4px 54px; list-style: decimal; }
.archive-steps li { padding: 20px 0; color: #536f94; font-size: 15px; line-height: 1.95; }
.archive-steps li::marker { color: #6386b6; font-weight: 600; }.archive-steps li + li { border-top: 1px solid #edf1f7; }
.archive-steps p { margin: 0; }.archive-steps .archive-equation { margin-top: 12px; padding: 12px 16px; border-radius: 6px; background: #f3f6fb; color: #315c99; font: 500 17px/1.8 var(--display); overflow-wrap: anywhere; }
.archive-result,.archive-check-explanation,.archive-pitfall { margin: 22px 24px; padding: 20px; border-radius: 8px; font-size: 14px; line-height: 1.9; }
.archive-result { background: #edf6f1; color: #427e62; }.archive-result strong { font-size: 12px; }.archive-result > p { margin: 8px 0 0; font-size: 22px; font-weight: 500; color: #27634d; overflow-wrap: anywhere; }
.archive-check-explanation { background: #f4f7fb; color: #68809f; }.archive-pitfall { background: #fbf6ed; color: #95774f; }
.archive-check-explanation h3,.archive-pitfall h3 { font: 600 17px/1.5 var(--display); margin: 0 0 9px; }.archive-check-explanation p,.archive-pitfall p { margin: 0; }
.archive-answer-form,.archive-proof-draft,.archive-hints,.archive-related,.archive-next { padding: 22px; border: 1px solid #dde5f0; border-radius: 9px; background: #fff; margin-bottom: 18px; }
.archive-answer-form h2,.archive-proof-draft h2,.archive-hints h2,.archive-related h2 { margin: 0 0 18px; font: 600 19px/1.5 var(--display); color: var(--blue-night); }
.archive-answer-form label { display: grid; gap: 8px; font-size: 12px; color: #6b83a3; }
.archive-answer-form input,.archive-proof-draft textarea { width: 100%; min-width: 0; min-height: 48px; padding: 12px; border: 1px solid #c5d4e7; border-radius: 6px; font: 400 16px/1.6 var(--display); color: var(--blue-night); background: #fff; }
.archive-proof-draft textarea { resize: vertical; margin-bottom: 12px; }
.archive-help { color: #7d90aa; font-size: 12px; line-height: 1.8; margin: 10px 0 18px; }
.archive-feedback { font-size: 13px; line-height: 1.8; color: #a07e4c; margin: 14px 0 0; }.archive-feedback.correct { color: #3d8168; }
.archive-hints { background: #f9fafc; }.archive-hints details + details { margin-top: 14px; }.archive-hints summary { color: #5676a2; cursor: pointer; min-height: 44px; font-size: 14px; line-height: 1.8; }.archive-hints p { font-size: 13px; line-height: 1.9; color: #6c819c; margin: 10px 0 0; }
.archive-hints details[hidden] { display: none; }
.archive-related { background: #f5f8fc; }.archive-related .archive-link { display: flex; font-size: 13px; }
.archive-next { background: #f4f7fc; border-color: #e3eaf3; }.archive-next .archive-link { font-weight: 500; font-size: 16px; }
.archive-self-review { border: 0; border-top: 1px solid #e4ebf4; margin: 22px 24px; padding: 18px 0 0; }.archive-self-review legend { font-size: 15px; color: #55769c; padding-right: 10px; }.archive-self-review label { display: flex; align-items: flex-start; gap: 9px; font-size: 13px; line-height: 1.9; color: #7188a6; margin: 12px 0; min-height: 44px; padding-block: 6px; }.archive-self-review input { margin-top: 5px; accent-color: #4d79b5; }
#archive-app :where(a,button,input,select,textarea,summary):focus-visible { outline: 2px solid #4f79b4; outline-offset: 3px; }
@media(max-width:1000px) { .archive-reading-layout { grid-template-columns: minmax(0,1fr) 280px; gap: 22px; }.archive-card { grid-template-columns: 35px minmax(0,1fr) 125px; gap: 16px; }.archive-filter-heading { display: block; }.archive-filter-heading p { margin-top: 9px; } }
@media(max-width:760px) {
 .archive-reading-layout { display: flex; flex-direction: column; align-items: stretch; gap: 18px; }
 .archive-reading-main,.archive-reading-aside { display: contents; }
 .archive-question { order: 0; margin: 0; }
 .archive-answer-form,.archive-proof-draft { order: 1; margin: 0; }
 .archive-hints { order: 2; margin: 0; }
 .archive-solution { order: 3; }
 .archive-reading-aside .archive-related { order: 4; display: block; margin: 0; width: 100%; }
 .archive-reading-aside .archive-next { order: 5; display: block; margin: 0; width: 100%; }
 .archive-card { grid-template-columns: 28px minmax(0,1fr); gap: 12px; padding-block: 20px; }
 .archive-card-action { grid-column: 2; text-align: left; }
}
@media(max-width:600px) {
 body[data-page='archive'] .page-section { padding-top: 24px; }.archive-intro h1,.archive-problem-heading h1 { font-size: 34px; }.archive-intro > p.archive-lead { font-size: 14px; }.archive-stats { gap: 8px; }.archive-stats-path { width: 100%; border: 0; padding: 0; margin: 0; font-size: 11px; }
 .archive-filters { padding: 18px; gap: 16px; }.archive-selects { grid-template-columns: repeat(2,minmax(0,1fr)); gap: 12px; }.archive-selects label:nth-child(2) { grid-column: 1/-1; grid-row: 2; }.archive-selects select,.archive-search input { font-size: 16px; }
 .archive-results-heading { gap: 12px; }.archive-results-heading h2 { font-size: 22px; }.archive-results-heading p { font-size: 11px; }.archive-card { padding-inline: 0; }.archive-card h3 { font-size: 20px; }.archive-card-body > p { font-size: 13px; }.archive-meta { gap: 7px 9px; font-size: 10px; }
 .archive-pagination { gap: 12px; justify-content: space-between; }.archive-pagination .archive-button { padding-inline: 10px; font-size: 12px; }.archive-pagination > span { font-size: 11px; }
 .archive-problem-heading { margin-top: 22px; }.archive-question { padding: 18px; }.archive-question > p { font-size: 16px; line-height: 1.9; }.archive-question h2 { font-size: 20px; }.archive-diagram { padding: 5px; }.archive-diagram svg { min-height: 130px; }
 .archive-solution > summary { padding: 18px; font-size: 15px; }.archive-steps { padding: 0 18px 0 40px; }.archive-steps li { font-size: 14px; padding-block: 18px; }.archive-steps .archive-equation { padding: 10px 12px; font-size: 16px; }
 .archive-result,.archive-check-explanation,.archive-pitfall { padding: 16px; margin: 18px; }.archive-self-review { margin: 18px; }.archive-answer-form,.archive-proof-draft,.archive-hints { padding: 18px; }.archive-origin { font-size: 11px; }
}
@media(prefers-reduced-motion:reduce) { .archive-card { transition: none; } }