@import url('/base.css');
:root{--ink:#203a35;--green:#184f46;--soft:#e7ede3;--lime:#dbedb8;--paper:#f6f7f2;--muted:#65756e;--border:#dce3d8;--red:#ad473d;--gold:#c89a31}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:Inter,"Segoe UI","Microsoft YaHei",system-ui,sans-serif;font-size:15px;line-height:1.6}button,input,select{font:inherit}button,a{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button{touch-action:manipulation}button:disabled{cursor:default;opacity:.5}a{color:var(--green)}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,[tabindex]:focus-visible{outline:3px solid #d99d30;outline-offset:3px}button{border:0;background:none;color:inherit}button:not(.key):active{transform:translateY(1px)}.site-header{max-width:1400px;margin:auto;padding:27px 5%;display:flex;align-items:center;gap:24px;border-bottom:1px solid var(--border)}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;white-space:nowrap}.brand-mark{width:46px;height:46px;background:var(--green);color:var(--lime);border-radius:13px;display:grid;place-content:center;position:relative;font:700 29px Georgia}.brand-mark span{position:absolute;right:7px;bottom:2px;font-size:20px}.brand strong{font-size:19px;letter-spacing:.04em}.brand small{display:block;font-size:10px;color:#7b8272;letter-spacing:.15em}.site-header nav{display:flex;gap:10px;margin-left:35px}.nav{padding:9px 16px;min-height:44px;border-radius:25px;font-size:14px;color:var(--muted);white-space:nowrap}.nav.active{background:var(--green);color:white}.nav span{font-size:10px;padding:1px 5px;border-radius:8px;background:#d6e0d0;color:var(--green)}.save-status{margin-left:auto;font-size:12px;color:var(--muted);white-space:nowrap}main{max-width:1220px;margin:0 auto;padding:36px 28px 50px;min-height:70vh}h1,h2,h3,p{margin-top:0}h1{font-size:46px;line-height:1.28;letter-spacing:-.035em;margin-bottom:18px;font-weight:750}h2{font-size:24px;line-height:1.4}h3{font-size:17px}p{color:var(--muted)}.eyebrow{font:600 11px/1.5 ui-monospace,monospace;letter-spacing:.17em;text-transform:uppercase;color:var(--muted);margin-bottom:12px}.hero{display:grid;grid-template-columns:1fr 350px;gap:32px;align-items:center;margin-bottom:32px;padding-top:8px}.hero p{font-size:15px;margin-bottom:0;max-width:500px}.hero h1 em{font-style:normal;color:#5f826b}.hero-art{width:250px;height:210px;margin:auto;position:relative}.orbit{position:absolute;border:1px solid #b8c7b6;border-radius:50%;width:240px;height:110px;left:0;top:45px;transform:rotate(-28deg)}.orbit:nth-child(2){transform:rotate(45deg);border-style:dashed}.atom-tile{position:absolute;background:var(--green);color:var(--lime);width:112px;height:132px;border-radius:17px;left:68px;top:35px;transform:rotate(-8deg);padding:12px 15px;box-shadow:15px 18px 0 #dde4d6}.atom-tile strong{display:block;font:64px/1 Georgia;text-align:center}.atom-tile small{font:11px ui-monospace,monospace}.atom-tile span{display:block;font-size:11px;text-align:center;margin-top:8px;letter-spacing:.08em}.orb-dot{position:absolute;right:6px;top:55px;background:#c2dba3;width:19px;height:19px;border:4px solid var(--paper);border-radius:50%}.hero-art:after{content:'每一次练习，都是新的反应';position:absolute;bottom:-4px;left:40px;color:#8b9982;font-size:10px;letter-spacing:.08em;transform:rotate(-8deg)}.dashboard{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:24px}.card{background:white;border:1px solid var(--border);border-radius:22px;padding:27px}.practice-card{background:var(--green);color:#fff;position:relative;overflow:hidden;min-height:285px;padding:30px 34px}.practice-card p{color:#b7ccc4}.practice-card .eyebrow{color:#a8c8ba}.practice-card h2{font-size:30px}.practice-card:after{content:'10';font:180px/1 Georgia;position:absolute;right:25px;top:20px;opacity:.055;pointer-events:none}.pill{display:inline-flex;align-items:center;gap:7px;padding:5px 12px;background:#ffffff14;border:1px solid #ffffff20;border-radius:30px;color:#d1e7c7;font-size:11px}.practice-bottom{display:flex;align-items:center;justify-content:space-between;margin-top:27px;gap:18px}.primary{background:var(--green);color:white;border-radius:12px;padding:13px 24px;font-weight:600;min-height:48px}.primary.light{background:var(--lime);color:#1b493e}.secondary{border:1px solid var(--border);border-radius:12px;padding:12px 20px;background:white;min-height:46px}.subtle{font-size:12px;color:var(--muted)}.practice-card .subtle{color:#bdd1c9}.rank-card{display:flex;flex-direction:column;text-align:center;justify-content:center;padding:20px}.rank-card svg{width:115px;margin:0 auto 4px}.rank-card h3{margin-bottom:5px}.rank-card .eyebrow{text-align:left;width:100%;margin:0}.rank-card p{font-size:12px;margin-bottom:0}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:0;padding:23px 7px;border:1px solid var(--border);border-radius:18px;background:#eff2e9;margin-top:22px}.stat{padding:0 20px;border-right:1px solid var(--border)}.stat:last-child{border:0}.stat b{display:block;font:600 27px/1.2 ui-monospace,monospace;margin-bottom:5px}.stat span{font-size:12px;color:var(--muted)}.mini-row{display:flex;align-items:center;gap:15px;margin:0 0 15px}.mini-icon{background:#f0f3e9;border:1px solid var(--border);height:40px;width:40px;display:grid;place-content:center;border-radius:12px;color:var(--green);font-size:20px}.mini-row p{font-size:12px;margin:0}.mini-row strong{font-size:14px}.small-title{display:flex;justify-content:space-between;align-items:center;margin-bottom:18px}.small-title h3{margin:0}.link{font-size:12px;text-decoration:underline;text-underline-offset:4px;min-height:44px;padding:5px 6px}.section-gap{margin-top:23px}.rules-strip{display:flex;gap:14px;margin-top:24px;font-size:12px;color:var(--muted);flex-wrap:wrap}.rules-strip span+span:before{content:'·';margin-right:14px}footer{max-width:1164px;border-top:1px solid var(--border);margin:auto;padding:16px 0 24px;display:flex;align-items:center;justify-content:space-between;font-size:11px;color:#849080}.skip{position:absolute;left:-9999px}.skip:focus{left:15px;top:10px;background:white;padding:10px;z-index:10}.loading{text-align:center;padding:90px 20px}.notice{background:#fff4dd;border:1px solid #e8d6ad;padding:13px 18px;border-radius:12px;font-size:13px;color:#735426;margin-bottom:20px}.round-heading{display:flex;justify-content:space-between;align-items:center;margin-bottom:18px}.round-heading h2{margin:0;font-size:20px}.round-topline{display:flex;gap:16px;align-items:center}.question-layout{display:grid;grid-template-columns:minmax(0,1fr) 285px;gap:24px}.question-card{padding:26px 32px}.question-meta{display:flex;justify-content:space-between;color:var(--muted);font-size:12px}.progress{display:flex;gap:7px;margin:17px 0 28px}.progress span{height:5px;flex:1;background:#e6ebe2;border-radius:4px}.progress .done{background:#83aa81}.progress .wrong{background:#d99482}.progress .current{background:var(--green)}.question-prompt{text-align:center}.question-prompt h1{font-size:34px;margin:12px 0 7px;letter-spacing:.025em}.question-prompt p{font-size:13px;min-height:22px;margin-bottom:18px}.category{font-size:11px;border:1px solid var(--border);border-radius:7px;padding:4px 9px;color:var(--muted);display:inline-block}.answer-field{background:#f6f8f3;border:1.5px solid #bfcfbb;border-radius:13px;min-height:76px;padding:12px 18px;text-align:center;font-family:"Cambria Math",Georgia,serif;font-size:34px;letter-spacing:.025em;line-height:1.45;word-break:break-all;cursor:text}.answer-field.empty{color:#97a292;font-family:inherit;font-size:14px;line-height:48px}.answer-field:focus{border-color:var(--green);outline-offset:3px}.answer-note{text-align:center;color:#7b8978;font-size:11px;margin:9px 0 16px}.keypad{background:#eef2e8;border:1px solid #e0e7d9;border-radius:15px;padding:12px}.keyboard-head{display:flex;justify-content:space-between;align-items:center;font-size:11px;color:var(--muted);margin:0 0 9px}.toggle{display:flex;border:1px solid #cad5c2;border-radius:8px;overflow:hidden}.toggle button{padding:6px 12px;min-height:32px;font-size:12px}.toggle button.selected{background:var(--green);color:white}.key-grid{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:6px}.key{background:#fff;border:1px solid #d9e1d3;border-bottom-width:3px;border-radius:8px;min-height:44px;line-height:1;font:500 18px "Cambria Math",Georgia,serif;padding:5px 0;color:#284d3e}.key:active{background:#d7e7c7;transform:translateY(1px);border-bottom-width:1px}.key.num{background:#e2ead9;color:#335b40}.key.control{font-family:inherit;font-size:12px}.key.wide{grid-column:span 2}.key.enter{background:var(--green);color:white;border-color:var(--green);grid-column:span 3;font-family:inherit;font-size:14px}.keyboard-actions{display:grid;grid-template-columns:repeat(7,1fr);gap:6px;margin-top:8px}.feedback{border-radius:14px;padding:18px 20px;margin:18px 0 0;background:#edf5e7;border:1px solid #c7dec0}.feedback.wrong{background:#fcf0eb;border-color:#e8c5b9}.feedback strong{color:#285839}.feedback.wrong strong{color:var(--red)}.feedback p{font-size:13px;margin:7px 0;color:#5c6c59}.feedback-title{display:flex;gap:8px;align-items:center}.correct-formula{font-family:"Cambria Math",Georgia,serif;font-size:32px;margin:8px 0}.valence-line{display:flex;align-items:flex-end;gap:10px;flex-wrap:wrap;margin:15px 0 6px}.valence-label{font-size:12px;align-self:center}.valence-formula{display:inline-flex;align-items:flex-end;white-space:nowrap;font-family:"Cambria Math",Georgia,serif;line-height:1}.valence-unit{display:inline-flex;flex-direction:column;align-items:stretch;text-align:center}.valence-top{font:14px/1.3 "Cambria Math",Georgia,serif;height:21px;color:#43623b;min-width:100%;letter-spacing:0}.valence-bottom{font-size:28px;line-height:1.2}.next-row{display:flex;justify-content:flex-end;margin-top:16px}.round-aside .card{padding:22px;margin-bottom:18px}.round-aside p{font-size:12px;margin-bottom:7px}.round-aside h3{font-size:15px}.round-score{font-size:32px;font-family:ui-monospace,monospace}.round-aside .badge-small{width:68px;float:right}.help-example{font-family:"Cambria Math",Georgia,serif;font-size:23px;color:var(--green);margin:15px 0}.result-hero{text-align:center;max-width:650px;margin:auto}.result-hero svg{width:145px;height:145px}.result-hero h1{font-size:32px;margin:4px 0 8px}.result-hero p{font-size:14px}.result-score{font:600 56px/1.3 ui-monospace,monospace;color:var(--green);margin:15px 0 5px}.result-actions{display:flex;justify-content:center;gap:12px;margin:25px 0}.result-list{max-width:850px;margin:26px auto}.review-item{padding:17px 0;border-bottom:1px solid var(--border);display:flex;align-items:center;gap:16px;flex-wrap:wrap}.review-item:last-child{border:0}.review-symbol{font-size:19px;color:#538544}.review-symbol.bad{color:var(--red)}.review-item .name{min-width:130px;flex:1}.review-item small{color:var(--muted)}.review-item .formula{font-size:24px;font-family:"Cambria Math",Georgia,serif}.review-item .submitted{font-size:12px;color:var(--red);width:100%;margin-left:35px}.library-controls{display:flex;gap:12px;margin:20px 0;flex-wrap:wrap}input,select{border:1px solid #c9d5c1;background:white;border-radius:10px;padding:11px 13px;min-height:45px;max-width:100%;color:var(--ink)}input[type=search]{flex:1;min-width:180px}.library-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}.substance{padding:20px}.substance h3{margin:10px 0 3px}.substance p{font-size:12px;margin:5px 0}.substance .formula{font-size:28px;font-family:"Cambria Math",Georgia,serif;margin:13px 0}.substance details{font-size:12px;color:var(--muted)}summary{cursor:pointer;min-height:35px}.prose{max-width:850px;margin:auto}.prose section{margin-bottom:22px}.prose p,.prose li{font-size:14px;line-height:1.9}.prose h2{font-size:21px;margin:0 0 15px}.prose ul{padding-left:20px}.prose a{word-break:break-all}.rank-rules{display:flex;flex-wrap:wrap;gap:9px}.rank-chip{padding:8px 12px;border-radius:9px;background:#edf1e6;font-size:12px}.empty-state{padding:45px;text-align:center}.history-list{font-size:12px}.history-list div{display:flex;justify-content:space-between;padding:8px 0;border-bottom:1px solid var(--border)}#toast{position:fixed;left:50%;bottom:26px;transform:translateX(-50%);background:#233f36;color:white;padding:12px 22px;border-radius:12px;z-index:25;box-shadow:0 4px 30px #0002;display:none;max-width:90vw}body.practice footer{display:none}.status-detail{font-size:11px;max-width:400px;color:var(--muted);margin-top:10px}.admin-wrap{max-width:1100px;margin:auto;padding:35px 20px}.admin-login{max-width:410px;margin:50px auto}.admin-login input{width:100%;margin:7px 0 17px}.admin-stats{display:grid;grid-template-columns:repeat(4,1fr);gap:15px;margin:25px 0}.admin-stats .card{padding:18px}.admin-stats b{font-size:29px;display:block}.table-wrap{overflow:auto}table{border-collapse:collapse;width:100%;font-size:13px;white-space:nowrap}th,td{text-align:left;padding:12px;border-bottom:1px solid var(--border)}th{font-size:12px;color:var(--muted)}.admin-toolbar{display:flex;gap:12px;justify-content:space-between;align-items:center}.error{color:var(--red)}.detail-row td{white-space:normal;background:#f5f7f0}.admin-page .site-header{max-width:1100px}
@media(min-width:1200px){.question-card{max-width:760px}.key-grid{grid-template-columns:repeat(10,minmax(0,1fr))}.keyboard-actions{grid-template-columns:repeat(7,1fr)}}
@media(max-width:900px){.site-header{padding:18px 25px;flex-wrap:wrap;gap:12px}.site-header nav{margin-left:auto;gap:3px}.save-status{display:none}.dashboard{grid-template-columns:minmax(0,1fr) 280px}.hero{grid-template-columns:1fr 260px}.question-layout{grid-template-columns:1fr}.round-aside{display:none}.library-grid{grid-template-columns:repeat(2,1fr)}footer{margin:0 28px}.nav{padding:8px 11px}}
@media(max-width:620px){.site-header{padding:16px 18px 11px;gap:13px}.brand-mark{width:37px;height:39px;font-size:25px}.brand strong{font-size:17px}.brand small{font-size:9px}.site-header nav{width:100%;justify-content:space-between;margin:0;border-top:1px solid var(--border);padding-top:9px}.nav{flex:1;padding:6px 8px;min-height:40px;font-size:13px}.brand{gap:10px}main{padding:25px 18px 35px}.hero{grid-template-columns:1fr;gap:0;padding-top:0;margin-bottom:24px}.hero-art{display:none}h1{font-size:36px;margin-bottom:13px}.hero p{font-size:13px;max-width:320px}.eyebrow{font-size:10px}.dashboard{grid-template-columns:1fr;gap:18px}.card{padding:21px;border-radius:18px}.practice-card{min-height:257px;padding:25px}.practice-card h2{font-size:26px}.practice-card:after{font-size:160px;right:15px}.practice-bottom{margin-top:25px}.practice-bottom .subtle{max-width:95px;font-size:11px}.stats{margin-top:18px;padding:20px 0}.stat{padding:0 13px}.stat b{font-size:24px}.stat span{font-size:10px}.rank-card{display:grid;grid-template-columns:80px 1fr;text-align:left;gap:0 17px}.rank-card svg{grid-column:1;grid-row:1/4;width:80px}.rank-card .eyebrow{grid-column:2}.rank-card h3{grid-column:2}.rank-card p{grid-column:2;font-size:11px}.rules-strip{gap:6px;font-size:10px}.rules-strip span+span:before{margin-right:6px}footer{margin:0 18px;font-size:10px;gap:10px}.section-gap{margin-top:18px}.question-card{padding:18px 14px}.question-prompt h1{font-size:27px;margin:8px 0 3px}.question-prompt p{font-size:12px;margin:0 0 11px;min-height:19px}.progress{margin:12px 0 18px;gap:5px}.question-meta{font-size:11px}.answer-field{min-height:65px;font-size:31px;padding:7px 10px}.answer-field.empty{line-height:49px;font-size:13px}.answer-note{font-size:10px;margin:7px 0 10px}.keypad{padding:8px;border-radius:12px}.key-grid{gap:5px}.key{min-height:44px;border-radius:7px;font-size:17px}.keyboard-actions{gap:5px}.keyboard-head{margin-bottom:8px}.toggle button{padding:6px 10px;min-height:36px}.round-heading{margin-bottom:12px}.round-heading h2{font-size:17px}.round-heading .secondary{font-size:12px;padding:8px 12px;min-height:40px}body.practice main{padding:15px 12px 20px}body.practice .site-header{padding:10px 16px}body.practice .site-header nav{display:none}body.practice .brand-mark{width:32px;height:33px;font-size:22px}body.practice .brand strong{font-size:15px}body.practice .brand small{font-size:8px}.feedback{padding:14px;margin-top:12px}.valence-bottom{font-size:26px}.valence-top{font-size:13px}.library-grid{grid-template-columns:1fr}.review-item{gap:10px}.review-item .name{min-width:95px}.review-item .formula{font-size:21px}.result-hero h1{font-size:29px}.result-score{font-size:48px}.result-actions button{padding:12px 18px}.prose p,.prose li{font-size:13px}.admin-stats{grid-template-columns:repeat(2,1fr)}.admin-toolbar{flex-wrap:wrap}.next-row .primary{width:100%}.empty-state{padding:35px 20px}}
.valence-sub{font-size:28px;line-height:1.2}.valence-formula{padding-top:2px}
@media(max-width:620px){.key-grid{grid-template-columns:repeat(6,minmax(0,1fr))}.question-prompt h1{margin-top:6px}.progress{margin-bottom:12px}}
@media(max-width:379px){.key-grid{grid-template-columns:repeat(5,minmax(0,1fr))}}
@media(max-width:340px){body.practice main{padding-left:8px;padding-right:8px}.question-card{padding-left:10px;padding-right:10px}.keypad{padding:6px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
/* A chemistry keyboard: paired cases in alphabetical order, with a separate number pad. */
.paired-letters{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:7px}.letter-pair{display:grid;grid-template-columns:1fr 1fr;gap:2px;min-width:0}.letter-pair .key{min-height:48px;font-size:21px}.letter-pair .upper-key{border-radius:8px 3px 3px 8px;background:#fff}.letter-pair .lower-key{border-radius:3px 8px 8px 3px;background:#e0ead7;color:#345e3c}.keyboard-bottom{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:12px}.keypad-label{font-size:10px;color:var(--muted);margin-bottom:5px}.number-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:5px}.number-grid .key,.symbol-grid .key{min-height:44px}.number-grid .num{font:600 21px/1 ui-monospace,monospace;background:#fff}.zero-key{grid-column:1/-1}.symbol-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:5px}.symbol-grid .backspace-key,.symbol-grid .enter{grid-column:1/-1}.symbol-grid .control{font-size:13px}.symbol-grid .enter{font-size:14px}.keypad{padding:12px}.keyboard-head{margin-bottom:8px}.element-tip{color:var(--green)}
@media(max-width:620px){
 body.practice .site-header{padding:6px 12px}body.practice .brand-mark{width:28px;height:29px}body.practice main{padding:6px 8px 12px}body.practice .round-heading{margin-bottom:5px}body.practice .round-heading h2{font-size:14px}body.practice .round-topline{gap:9px}body.practice .round-heading .secondary{min-height:36px;padding:4px 10px}body.practice .question-card{padding:10px;border-radius:14px}body.practice .question-meta{font-size:10px}.question-meta span:last-child{display:none}body.practice .progress{margin:6px 0 8px}body.practice .question-prompt{position:relative}body.practice .question-prompt .category{font-size:10px;padding:1px 6px}body.practice .question-prompt h1{font-size:24px;margin:3px 0 1px}body.practice .question-prompt p{margin:0 0 6px;min-height:0;font-size:11px}body.practice .answer-field{min-height:50px;padding:5px 8px;font-size:27px;line-height:38px}body.practice .answer-field.empty{font-size:12px;line-height:38px}body.practice .answer-note{font-size:9px;margin:4px 0 6px}
 .keypad{padding:7px}.keyboard-head{font-size:10px;margin-bottom:6px}.paired-letters{grid-template-columns:repeat(4,minmax(0,1fr));gap:5px}.letter-pair{gap:2px}.letter-pair .key{min-height:44px;font-size:20px}.keyboard-bottom{gap:10px;margin-top:8px}.keypad-label{margin-bottom:4px}.number-grid .key,.symbol-grid .key{min-height:44px}.number-grid .num{font-size:21px}.symbol-grid .enter{font-size:13px}
}
@media(max-width:359px){.paired-letters{grid-template-columns:repeat(3,minmax(0,1fr))}.keyboard-head{font-size:9px}}
@media(max-width:620px){
 body.practice .site-header{padding:3px 12px}body.practice main{padding-top:3px;padding-bottom:max(8px,env(safe-area-inset-bottom))}body.practice .round-heading{margin-bottom:3px}body.practice .round-heading .secondary{min-height:32px}body.practice .question-card{padding-top:7px}body.practice .progress{margin:3px 0 5px}body.practice .question-prompt{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:1px 7px}body.practice .question-prompt h1{margin:0;font-size:23px}body.practice .question-prompt p{flex-basis:100%;margin-bottom:4px;font-size:10px}body.practice .answer-field{min-height:44px;line-height:32px}body.practice .answer-field.empty{line-height:32px}body.practice .answer-note{display:none}body.practice .keypad{margin-top:6px}
}

/* The label colon shares the exact 21px row with the valence figures. */
.valence-line{align-items:flex-start;gap:8px;flex-wrap:nowrap}
.valence-label{align-self:flex-start;flex-shrink:0;font-size:14px;height:21px;line-height:21px}
.valence-formula{padding-top:0;max-width:100%}
.valence-top{font-size:14px;line-height:21px;height:21px}
.valence-bottom,.valence-sub{font-size:28px;line-height:1.2}
.memory-hints{display:flex;flex-wrap:wrap;gap:5px;justify-content:center;margin:6px 0}
.memory-hints span{font-size:11px;line-height:1.5;color:#315943;background:#edf3e6;border-radius:6px;padding:3px 7px}
.question-prompt .property-condition,.property-condition{font-size:10px;color:var(--muted);margin:4px 0 8px;min-height:0}
.substance .memory-hints{justify-content:flex-start}.substance .property-condition{font-size:11px}
.related-ions{border-top:1px solid #ccd9c5;margin-top:14px;padding-top:12px}
.related-ions h4{font-size:14px;margin:0 0 10px}
.ion-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:10px}
.ion-card{background:#f9fbf6;border:1px solid var(--border);border-radius:12px;padding:12px;min-width:0}
.ion-card-heading{display:flex;align-items:center;justify-content:space-between;gap:6px;font-size:14px}
.ion-card-heading small{font-size:10px;color:var(--muted)}
.ion-symbol-row{display:flex;align-items:center;gap:12px;margin:8px 0;color:var(--muted);font-size:12px}
.ion-symbol{font:26px/1.6 "Cambria Math",Georgia,serif;color:var(--ink);white-space:nowrap}
.ion-symbol sup{font-size:.58em;vertical-align:super;line-height:0;margin-left:1px}
.ion-card .valence-line{margin:7px 0 0}.ion-card .valence-label{font-size:12px}
.ion-note,.feedback .ion-note{font-size:11px;line-height:1.7;margin:10px 0 0}
.ion-reference{margin:18px 0;padding:18px}.ion-reference summary{cursor:pointer;font-weight:650;min-height:30px}
.ion-reference>p{font-size:12px;margin:10px 0}
@media(max-width:620px){body.practice .question-prompt .memory-hints{flex-basis:100%;gap:4px;margin:2px 0 3px}body.practice .question-prompt .memory-hints span{font-size:10px;padding:2px 5px}body.practice .question-prompt .property-condition{font-size:9px;margin:0 0 4px}.ion-grid{grid-template-columns:repeat(auto-fit,minmax(180px,1fr))}.ion-card{padding:10px}}

.brand-mark.brand-image{display:block;object-fit:contain;background:transparent;border-radius:10px;flex-shrink:0}

.ion-entry{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:24px;background:#eaf0f8;border-color:#cdd8e7}.ion-entry h2{margin:8px 0}.ion-entry p{margin:0;font-size:13px}.ion-entry .primary{flex-shrink:0;background:#304d80}.ion-lobby h1{font-size:30px}.ion-lobby .secondary{margin:10px}.ion-demo{display:flex;align-items:center;flex-wrap:wrap;gap:15px;margin:20px 0;font-size:12px;color:var(--muted)}.ion-demo strong{font:36px "Cambria Math",Georgia,serif;color:#304d80}.charge-pad{margin:10px 0;padding:9px;background:#e2eafa;border:1px solid #c4d2eb;border-radius:10px}.charge-grid{display:grid;grid-template-columns:repeat(6,1fr);gap:6px}.charge-key{color:#274d87}.charge-pad p{font-size:10px;margin:6px 0 0}.ion-lobby .primary{background:#304d80}
@media(max-width:620px){.site-header nav{gap:1px}.nav{padding:9px 11px}.ion-entry{display:block;padding:20px}.ion-entry .primary{margin-top:15px;width:100%}.ion-entry h2{font-size:20px}.ion-lobby{padding:20px}.ion-lobby h1{font-size:25px}.ion-lobby .primary,.ion-lobby .secondary{width:100%;margin:8px 0}.charge-pad{margin:6px 0;padding:6px}.charge-grid{gap:4px}.charge-pad .key{min-height:40px}.charge-pad p{font-size:9px}}

/* Compact, persistent navigation on every view, including mobile practice. */
html{scroll-padding-top:96px}
.site-header{position:sticky;top:0;z-index:20;background:var(--paper);max-width:none;padding:8px max(20px,calc((100vw - 1260px)/2));gap:18px;box-shadow:0 2px 8px #203a3508}
.site-header .brand-mark{width:32px;height:32px}
.site-header .brand{gap:8px}
.site-header .brand strong{font-size:17px;line-height:1.3}
.site-header .brand small{font-size:9px;line-height:1.3}
.site-header nav{margin-left:14px;gap:4px}
.site-header .nav{padding:6px 13px;min-height:40px}
.skip:focus{position:fixed;z-index:30}
@media(max-width:900px){.site-header{padding:7px 16px;gap:6px 12px}.site-header nav{margin-left:auto}}
@media(max-width:620px){
 .site-header,body.practice .site-header{padding:4px max(10px,env(safe-area-inset-right)) 4px max(10px,env(safe-area-inset-left));padding-top:max(4px,env(safe-area-inset-top));gap:2px}
 .site-header .brand-mark,body.practice .site-header .brand-mark{width:24px;height:24px}
 .site-header .brand{gap:7px}
 .site-header .brand>span{display:flex;align-items:baseline;gap:9px}
 .site-header .brand strong,body.practice .site-header .brand strong{font-size:14px;letter-spacing:.02em}
 .site-header .brand small,body.practice .site-header .brand small{font-size:8px;letter-spacing:.02em}
 .site-header nav,body.practice .site-header nav{display:flex;width:100%;margin:0;padding-top:2px;gap:2px;border-top:0}
 .site-header .nav{flex:1;min-width:0;min-height:40px;padding:5px 4px;font-size:12px}
 .site-header .nav span{padding:1px 4px}
}

.ion-group-title{margin:20px 0 10px}.ion-coverage-note{font-size:12px;background:#f0f4e9;border-radius:10px;padding:10px 12px;color:var(--green)}
.element-ion-guide{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:12px;margin-top:15px}.element-ion-guide article{border:1px solid var(--border);border-radius:12px;padding:14px}.element-ion-guide h3{margin:0 0 8px;font-size:15px}.element-ion-guide h3 small{font-weight:400;color:var(--muted)}.element-ion-guide h3>span{float:right;font-family:Georgia,serif}.element-ion-guide p{font-size:11px;margin:10px 0 0}.guide-symbols{display:flex;flex-wrap:wrap;gap:10px}.guide-symbols>span{display:flex;flex-direction:column}.guide-symbols small{font-size:10px;color:var(--muted)}

.extension-badge{display:inline-block;font-size:10px;padding:2px 7px;margin-top:7px;border-radius:6px;background:#f7edd7;color:#765a22}

/* Compact practice: one toolbar, one prompt, no instructional rows above keys. */
.practice-toolbar{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--muted);min-height:30px}
.question-count{margin-left:auto;font-variant-numeric:tabular-nums}
.pause-button{font-size:12px;min-height:30px;padding:3px 8px;border:1px solid var(--border);border-radius:8px}
body.practice .question-prompt{display:flex;align-items:center;justify-content:flex-start;flex-wrap:wrap;gap:5px 9px;margin:4px 0 8px;text-align:left}
body.practice .question-prompt h1{font-size:28px;margin:0;line-height:1.25}
body.practice .question-prompt .category{font-size:11px;padding:1px 6px}
body.practice .question-prompt .extension-badge{margin:0}
.compact-keypad .letter-tools{grid-column:span 2;display:grid;grid-template-columns:1fr 1fr;gap:5px}
.compact-keypad .keyboard-bottom{grid-template-columns:1fr 1fr;gap:8px;margin-top:6px}
.compact-keypad .symbol-grid{height:100%;grid-template-columns:repeat(3,minmax(0,1fr));grid-template-rows:1fr 2fr;gap:5px}
.compact-keypad .symbol-grid.with-zero{grid-template-columns:repeat(4,minmax(0,1fr))}
.compact-keypad .symbol-grid .enter{grid-column:1/-1;grid-row:2;border-radius:10px;font-size:16px}
.compact-keypad .charge-pad{padding:0;border:0;background:none;margin:6px 0 0}
.compact-keypad .charge-grid{gap:5px}
.compact-keypad .charge-key{background:#e2eafa;border-color:#c4d2eb;font-family:inherit;font-size:18px}
.compact-keypad .charge-key sup{position:relative;top:-3px;font-size:14px}
.ion-lobby-title{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:12px}
.ion-lobby-title h1{margin:0;font-size:26px}.ion-lobby .subtle{margin:8px 0 0}
@media(max-width:620px){
 body.practice main{padding:4px 6px max(6px,env(safe-area-inset-bottom))}
 body.practice .question-card{padding:6px;border-radius:12px}
 body.practice .practice-toolbar{min-height:28px;font-size:11px;line-height:1.2}
 body.practice .pause-button{min-height:28px;padding:2px 8px;font-size:11px}
 body.practice .question-prompt{margin:2px 0 5px;gap:3px 7px}
 body.practice .question-prompt h1{font-size:22px;line-height:1.2}
 body.practice .answer-field{min-height:42px;line-height:30px;padding:5px 8px;font-size:26px}
 body.practice .answer-field.empty{line-height:30px}
 body.practice .compact-keypad{padding:5px;margin-top:5px}
 .compact-keypad .paired-letters{grid-template-columns:repeat(5,minmax(0,1fr));gap:4px}
 .compact-keypad .letter-pair{gap:1px}
 .compact-keypad .letter-pair .key{min-height:40px;font-size:19px;padding:3px 0}
 .compact-keypad .letter-tools{grid-column:span 4;gap:4px}
 .compact-keypad .letter-tools .key{min-height:40px;font-size:13px}
 .compact-keypad .number-grid{gap:4px}
 .compact-keypad .number-grid .key,.compact-keypad .symbol-grid .key,.compact-keypad .charge-pad .key{min-height:40px}
 .compact-keypad .number-grid .key{font-size:20px}
 .compact-keypad .keyboard-bottom{gap:6px;margin-top:5px}
 .compact-keypad .charge-pad{margin-top:5px}
 .compact-keypad .charge-grid{gap:4px}
 .ion-lobby{padding:15px}.ion-lobby-title{margin-bottom:8px}.ion-lobby-title h1{font-size:24px}
 .ion-lobby .primary,.ion-lobby .secondary{margin:4px 0;min-height:42px;padding:9px 14px}
}
@media(max-width:359px){.compact-keypad .paired-letters{grid-template-columns:repeat(4,minmax(0,1fr))}.compact-keypad .letter-tools{grid-column:span 2}}
@media(max-width:620px) and (max-height:620px){
 .compact-keypad .letter-pair .key,.compact-keypad .letter-tools .key,.compact-keypad .number-grid .key,.compact-keypad .symbol-grid .key,.compact-keypad .charge-pad .key{min-height:36px}
 body.practice .question-prompt h1{font-size:20px}
}