[hidden]{display:none!important}.title-row{justify-content:space-between}h1{font-size:23px;margin:0}h1 span{font-weight:500;margin-left:6px}.subtitle,.intro{color:var(--muted)}.intro{margin:16px 0}.home-card{min-height:145px;text-align:left}.home-card .tag{width:max-content}.ap-filters{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;padding:18px;background:white;border:1px solid var(--line);border-radius:12px;margin:16px 0}.ap-filters label,#randomConfig label{display:flex;flex-direction:column;gap:5px;color:var(--muted);font-size:13px}.ap-filters select,.ap-filters input,#randomUnit{width:100%;padding:10px;border:1px solid var(--line);border-radius:8px;background:white;color:var(--ink);min-height:42px}.search-label{grid-column:span 2}#randomConfig{padding:22px}#randomConfig p{color:var(--muted)}.session{position:sticky;top:85px;z-index:5;display:flex;justify-content:space-between;gap:12px;align-items:center;background:white;border:1px solid var(--line);border-radius:10px;padding:14px;box-shadow:var(--shadow);margin:16px 0}.session>div{display:flex;gap:12px;flex-wrap:wrap}#timer{font-variant-numeric:tabular-nums;color:var(--blue)}.answer-box{display:block!important}.answer-box.wrong{background:var(--red-soft);color:var(--red)}.answer-box.correct{background:var(--green-soft);color:var(--green)}.empty-state{padding:45px 20px;text-align:center;background:white;border:1px solid var(--line);border-radius:12px;color:var(--muted)}.empty-state strong{display:block;font-size:18px;color:var(--ink);margin-bottom:8px}.option{width:100%;text-align:left}.media img{cursor:zoom-in}.options-image{margin:14px 0}.options-image img{max-width:100%;max-height:650px;object-fit:contain;cursor:zoom-in}.tag.multiple{background:var(--amber-soft);color:var(--amber)}.question-text,.stem{white-space:pre-wrap;overflow-wrap:anywhere}.katex{font-size:1.05em}.katex-display{overflow-x:auto;overflow-y:hidden}.card-body{overflow:hidden}#more{display:block;margin:24px auto}dialog{border:0;border-radius:12px;width:95vw;max-width:1200px;max-height:95vh;padding:14px}dialog::backdrop{background:#18212fd9}dialog img{display:block;max-width:100%;max-height:82vh;object-fit:contain;margin:auto}dialog button{display:block;margin-left:auto;margin-bottom:12px}button:focus-visible,select:focus-visible,input:focus-visible{outline:3px solid #75aaff;outline-offset:2px}.favorite-btn{font-size:22px}.source{overflow-wrap:anywhere}
@media(max-width:700px){h1{font-size:18px}.ap-filters{grid-template-columns:repeat(2,minmax(0,1fr));padding:12px}.session{top:76px;align-items:flex-start;flex-direction:column}.home-card{min-height:125px}.card-body{padding:16px}.media img{max-height:450px}#modeSubtitle{max-width:80vw}}
.card{content-visibility:visible;align-self:start}
.filter-toggle{display:inline-flex;align-items:center;justify-content:center;font-size:13px;min-height:34px;padding:6px 9px}.toast{pointer-events:none}
/* Match the compact proportions and typography of the Physics Bowl reference. */
body{font-family:Arial,"Microsoft YaHei","PingFang SC",sans-serif;-webkit-font-smoothing:antialiased}h1{font-size:20px;line-height:1.2}.title-row{margin-bottom:0;min-height:44px}.home-card{min-height:92px;gap:6px;padding:14px;align-content:center}.home-card strong{font-size:17px}.home-card span{font-size:13px}.intro{font-size:13px}.home{gap:12px}.home #bankSummary{margin:0;text-align:center}.home .site-footer{margin-top:0}.topbar{z-index:20}.title-actions{flex-shrink:0}.home-icon-btn svg{width:19px;height:19px}.ap-filters{margin:12px 0;padding:14px}.ap-filters.collapsed{display:none}.session{top:74px;font-size:13px;flex-wrap:wrap}.session strong{font-size:14px}.session button{font-size:13px}.list-toolbar{display:flex;justify-content:space-between;align-items:center;gap:10px;margin:12px 0}.list-toolbar>div{display:flex;gap:8px}.list-toolbar button{font-size:13px;min-height:34px;padding:6px 10px}.question-list.single-column{grid-template-columns:1fr}.favorite-btn{display:inline-flex;align-items:center;justify-content:center}.favorite-btn svg{width:20px;height:20px;stroke:currentColor;fill:none;stroke-width:1.7}.favorite-btn.active svg{fill:#f6ce64;stroke:#916115}.answer-nav{display:flex;flex-wrap:wrap;gap:7px;margin:14px 0 20px}.answer-nav button{min-height:34px;min-width:34px;padding:4px 7px;font-size:13px}.answer-nav .answered{background:var(--blue-soft);border-color:#84aee5;color:var(--blue)}.answer-nav .correct{background:var(--green-soft);border-color:#7ac09b;color:var(--green)}.answer-nav .wrong{background:var(--red-soft);border-color:#f2b8b2;color:var(--red)}.back-top{position:fixed;right:20px;bottom:22px;z-index:25;box-shadow:var(--shadow);width:42px;height:42px;display:grid;place-items:center}.back-top svg{width:22px;height:22px}.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);z-index:100;background:var(--ink);color:white;padding:11px 18px;border-radius:9px;font-size:14px;max-width:85vw;box-shadow:var(--shadow)}#profileDialog{max-width:440px;padding:22px}#profileDialog header{display:flex;justify-content:space-between;align-items:center}#profileDialog h2{font-size:20px;margin:0}#profileDialog p{font-size:13px;color:var(--muted)}#profileDialog button{margin:0}#profileDialog header button{min-height:32px;font-size:20px;border:0}.profile-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:20px 0}.profile-stats div{text-align:center;background:var(--bg);padding:16px 5px;border-radius:8px;font-size:13px;color:var(--muted)}.profile-stats strong{display:block;font-size:23px;color:var(--ink)}.profile-actions{display:flex;gap:8px;flex-wrap:wrap}article.card{scroll-margin-top:190px}.card-head{align-items:center}.number{font-size:14px}.source{font-size:12px}.question-text,.stem{font-size:16px;line-height:1.6}.options-image img{border:1px solid var(--line);border-radius:8px}.option{color:var(--ink)}.option:hover:not(:disabled){border-color:#a3b8d3}.empty-state{font-size:14px}
@media(max-width:700px){h1{font-size:16px;max-width:58vw}.title-actions{gap:5px}.access-badge{font-size:10px;padding:3px 6px}.home-card{min-height:92px}.topbar-inner{padding:9px 14px}.title-row{min-height:40px}.ap-filters{gap:10px}#examLabel{grid-column:span 2}.session{top:66px}.session>div{gap:8px}.list-toolbar{align-items:flex-start}.list-toolbar button{font-size:12px}.back-top{right:12px;bottom:14px}.view-toggle{display:none}.question-list{grid-template-columns:1fr}.answer-nav{gap:6px}.answer-nav button{min-width:32px}.card-body{padding:12px}.question-text,.stem{font-size:15px}article.card{scroll-margin-top:220px}}
@media(max-width:700px){h1{max-width:40vw}.filter-toggle{font-size:12px;max-width:66px;padding:5px 7px}#viewToggle{display:none}}

@media(max-width:700px){.topbar-inner>.ap-filters{margin:8px 0 0;max-height:60vh;overflow-y:auto;overscroll-behavior:contain}}

@media(max-width:520px){
 .topbar-inner>.ap-filters{box-sizing:border-box;max-height:60vh;opacity:1;transform:translateY(0);overflow:hidden;transition:max-height .34s cubic-bezier(.22,1,.36,1),opacity .24s ease,transform .34s cubic-bezier(.22,1,.36,1),padding .34s cubic-bezier(.22,1,.36,1),margin .34s cubic-bezier(.22,1,.36,1);}
 .topbar-inner>.ap-filters.collapsed{display:grid;max-height:0;opacity:0;transform:translateY(-10px);padding-top:0;padding-bottom:0;margin-top:0;border-width:0;pointer-events:none;visibility:hidden;}
}

.random-submit-area{margin:20px 0 32px;padding:20px;text-align:center;background:var(--panel);border:1px solid var(--line);border-radius:12px}.random-submit-area p{font-size:14px;color:var(--muted);margin:0 0 12px}.random-submit-area button{min-width:140px}

.session{position:static;top:auto}.topbar-timer{font-size:13px;white-space:nowrap;font-variant-numeric:tabular-nums;color:var(--blue)}.topbar-inner:has(.topbar-timer:not([hidden])) .access-badge{display:none}
@media(max-width:700px){.topbar-inner:has(.topbar-timer:not([hidden])) h1{max-width:none;flex:1;min-width:0;font-size:14px}.topbar-timer{font-size:12px}.topbar-inner:has(.topbar-timer:not([hidden])) .title-actions{gap:4px}}

.submit-actions{display:flex;justify-content:center;gap:10px;flex-wrap:wrap}#submitProgress{display:block;margin-bottom:10px;font-size:14px}#unansweredDialog{max-width:440px;padding:20px}#unansweredDialog header{display:flex;align-items:center;justify-content:space-between}#unansweredDialog h2{font-size:18px;margin:0}#unansweredDialog header button{margin:0}#unansweredDialog p{font-size:14px;color:var(--muted)}#unansweredList button{margin:0}#unansweredList{margin-bottom:0}

.card-heading{display:flex;align-items:center;gap:12px;min-width:0}.practice-number{display:inline-flex;align-items:center;justify-content:center;width:38px;height:38px;flex-shrink:0;border-radius:9px;background:#ffffff;color:#171717;border:1px solid #171717;font-size:18px;font-weight:700;font-variant-numeric:tabular-nums}

.practice-number{width:auto;min-width:32px;height:38px;padding:0 4px 0 16px;border:0;border-left:3px solid #8f9cae;border-radius:0;background:transparent;color:#18212f;font-size:23px;font-weight:700}
.account-area {padding:16px 0;border-top:1px solid #e2e8f0;border-bottom:1px solid #e2e8f0;margin:16px 0;}
.account-area form {display:grid;gap:12px;}
.account-area form[hidden],.account-area div[hidden] {display:none;}
.account-area label {display:grid;gap:6px;font-size:14px;color:#334155;}
.account-area input {width:100%;box-sizing:border-box;padding:10px 12px;border:1px solid #cbd5e1;border-radius:8px;background:white;font:inherit;}
.auth-tabs {display:flex;gap:8px;flex-wrap:wrap;}
.auth-tabs button[aria-pressed=true] {background:#eef2f6;border-color:#64748b;color:#0f172a;}
#authMessage {font-size:14px;line-height:1.6;overflow-wrap:anywhere;}
#accountEmail {overflow-wrap:anywhere;font-weight:600;}

img[data-private-pending]{min-height:70px;min-width:180px;background:#f8fafc;}