:root{--paper:#f9f8f6;--ink:#132a13;--muted:#73766a;--line:#dedfd5;--sage:#e9eddf;--red:#ac4c35;--cream:#f1ebdf;--white:#fffefa;--serif:"Noto Serif TC","Songti TC","PMingLiU",serif;--sans:"PingFang TC","Microsoft JhengHei",system-ui,sans-serif;color-scheme:light;font-family:var(--sans);color:var(--ink);background:var(--paper);font-synthesis:none}
*{box-sizing:border-box}body{margin:0}button,input,select{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer}a{color:inherit;text-decoration:none}button{color:inherit}button:disabled{cursor:default;opacity:.42}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,[tabindex]:focus-visible{outline:3px solid #b57831;outline-offset:4px}input,select{max-width:100%}input[type=text],select{width:100%;background:var(--white);border:1px solid #c8cabc;border-radius:4px;padding:13px 14px;min-height:48px;color:var(--ink)}input[type=radio]{accent-color:var(--ink);width:18px;height:18px;flex:none}fieldset{margin:0;padding:0;border:0}legend{font-size:12px;letter-spacing:.06em;margin:22px 0 10px}h1,h2,h3,p{margin:0}h1,h2,h3{font-family:var(--serif);font-weight:700}button{border:0;background:transparent}strong,output,.question-text,.duel-problem,.player-score{font-variant-numeric:tabular-nums}.skip-link{position:fixed;top:-80px;left:15px;padding:12px;background:var(--ink);color:white;z-index:100}.skip-link:focus{top:10px}
.site-header{max-width:1512px;margin:auto;display:flex;align-items:center;justify-content:space-between;gap:28px;height:100px;padding:0 48px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:12px;flex-shrink:0;font-family:var(--serif);font-size:22px;font-weight:700;letter-spacing:.06em}.brand svg{width:38px;height:38px}.brand small{display:block;font-family:var(--sans);font-size:9px;font-weight:500;letter-spacing:.13em;margin-top:5px}.main-nav{display:flex;gap:8px;align-self:stretch;align-items:stretch}.main-nav a{display:flex;align-items:center;gap:9px;padding:0 18px;font-size:14px;position:relative;white-space:nowrap}.main-nav a span{font-size:10px;color:var(--muted)}.main-nav a[aria-current]{font-weight:700}.main-nav a[aria-current]:after{content:"";height:3px;background:var(--ink);position:absolute;bottom:-1px;left:18px;right:18px}.main-nav a:hover{background:#eeeee5}.header-note{font-size:11px;color:var(--muted);letter-spacing:.1em;white-space:nowrap}
main{max-width:1440px;margin:auto;padding:0 48px 55px}.page-intro{display:flex;align-items:center;justify-content:space-between;padding:49px 0 40px;gap:20px}.eyebrow{font-size:10px;letter-spacing:.17em;font-weight:700;color:var(--muted);line-height:1.5}.page-intro h1{font-size:clamp(30px,3.4vw,48px);letter-spacing:.025em;line-height:1.4;margin:10px 0 15px}.intro-description{font-size:14px;color:#717568;line-height:1.9;max-width:690px}.intro-seal{border:1px solid var(--red);color:var(--red);font-family:var(--serif);font-size:20px;padding:8px 7px;line-height:1.2;transform:rotate(5deg);margin-right:14px}.section-heading{display:flex;justify-content:space-between;font-size:12px;border-bottom:1px solid var(--line);padding:0 0 17px;margin-bottom:5px}.section-heading span+span{color:var(--muted);font-size:10px}.learn-layout{display:grid;grid-template-columns:235px minmax(0,1fr) 190px;gap:26px;align-items:start}.lesson-link{display:flex;width:100%;gap:12px;align-items:center;text-align:left;padding:18px 10px;border-bottom:1px solid var(--line);font-size:12px;min-height:75px;border-radius:2px}.lesson-link.active{background:var(--ink);color:var(--paper);border-color:var(--ink);margin-top:5px}.lesson-link:hover:not(.active){background:var(--sage)}.lesson-number{font-size:11px;color:#969b8c;font-family:Georgia,serif}.lesson-link.active .lesson-number{color:#c9d5ad}.lesson-link small{display:block;font-size:10px;font-weight:400;color:#89907f;margin-top:6px;letter-spacing:.06em}.lesson-link.active small{color:#bdc8af}.lesson-arrow{margin-left:auto;font-size:16px}.sidebar-note{margin-top:27px;border-left:2px solid #b9c3a3;padding-left:15px}.tiny-label{font-size:9px;color:var(--muted);letter-spacing:.14em}.sidebar-note p{font-family:var(--serif);font-size:17px;line-height:1.9;margin:9px 0 12px}.sidebar-note a{font-size:10px;color:var(--muted);border-bottom:1px solid #b6bbaa;padding-bottom:3px}
.learning-workspace{background:var(--white);border:1px solid var(--line);border-radius:6px;overflow:hidden}.board-topline{display:flex;align-items:center;justify-content:space-between;padding:17px 24px;border-bottom:1px solid var(--line);gap:10px}.text-button{font-size:12px;text-decoration:underline;text-underline-offset:4px;text-decoration-color:#c5c9ba;padding:8px 2px;min-height:36px}.text-button:hover{color:var(--red)}.lesson-copy{padding:24px 28px 0}.lesson-copy h2{font-size:23px;line-height:1.6}.lesson-copy p{font-size:12px;color:var(--muted);line-height:1.9;margin-top:10px;min-height:46px}.board-host{width:100%;max-width:720px;margin:auto}.teaching-board{padding:10px 14px 0}.abacus{display:block;width:100%;height:auto;overflow:visible;touch-action:none;user-select:none;-webkit-user-select:none}.bead{cursor:grab;transition:transform 180ms ease;outline:none}.bead .bead-shape{stroke:#402c20;stroke-width:.6}.bead:hover .bead-shape{stroke:#dec492;stroke-width:2}.bead:focus-visible .bead-shape,.bead.is-held .bead-shape{stroke:#f0c86f;stroke-width:3}.bead[aria-disabled=true]{cursor:default}.bead[aria-disabled=true]:hover .bead-shape{stroke:#402c20;stroke-width:.6}.place-label{font-family:var(--sans);font-size:14px;fill:#686c5e;letter-spacing:2px}.board-readout{display:flex;align-items:center;gap:16px;margin:8px 28px 0;padding:16px 0;border-top:1px solid var(--line)}.board-readout>span{font-size:10px;color:var(--muted)}.board-readout output{font-family:Georgia,serif;font-size:31px;line-height:1;letter-spacing:.04em}.clear-board{margin-left:auto}.demo-strip{display:flex;align-items:center;justify-content:space-between;padding:14px 28px;background:#f3f4ec;border-top:1px solid var(--line);gap:10px}.button{display:inline-flex;align-items:center;justify-content:center;gap:14px;min-height:45px;padding:12px 20px;border:1px solid transparent;border-radius:4px;font-size:12px;font-weight:600;line-height:1.3;touch-action:manipulation}.button-primary{background:var(--ink);color:#fffefa}.button-primary:hover:not(:disabled){background:#2e4726}.button-quiet{background:#f2f1e9;border-color:#d8d9ce;color:var(--ink)}.button-quiet:hover:not(:disabled){background:#e5e8db}.step-navigation{display:flex;align-items:center;gap:12px}.step-count{font-size:11px;min-width:32px;text-align:center;color:var(--muted)}.icon-button{height:40px;width:40px;border:1px solid #d8ddcc;border-radius:50%;font-size:18px;background:var(--white)}.step-caption{font-size:12px;line-height:1.85;color:#6b725e;background:#f3f4ec;min-height:77px;padding:0 28px 20px}
.lesson-notes{padding-top:15px}.note-mark{font-size:10px;color:var(--red);letter-spacing:.14em;display:flex;align-items:center;gap:10px}.note-mark:before{content:"";height:6px;width:6px;border:1px solid var(--red);transform:rotate(45deg)}.lesson-notes h3{font-size:22px;line-height:1.5;margin:20px 0 15px}.lesson-note{font-size:12px;line-height:2.1;color:#6e7567;min-height:125px}.bead-legend{border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:19px 0;display:flex;flex-direction:column;gap:15px;margin-top:18px;font-size:11px}.bead-legend span{display:flex;align-items:center;gap:14px}.legend-bead{display:inline-block;width:27px;height:14px;border-radius:50%;background:#7e452f;border:1px solid #59321f;box-shadow:inset 0 3px #a16244}.legend-bead.upper{background:#bc7a4b;box-shadow:inset 0 3px #d69b6d}.touch-tip{margin-top:23px}.touch-tip>span{font-size:11px;font-weight:700}.touch-tip p{font-size:11px;color:var(--muted);line-height:2;margin-top:10px}.practice-link{display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #c3c9b6;padding:22px 0 12px;font-size:11px;margin-top:12px}.practice-link span{font-size:19px}.site-footer{display:flex;justify-content:space-between;gap:20px;max-width:1344px;margin:auto;padding:23px 0 30px;border-top:1px solid var(--line);font-size:10px;color:#818775;letter-spacing:.09em}.site-footer span:last-child{font-size:8px}
.solo-layout{display:grid;grid-template-columns:310px minmax(0,1fr);gap:32px}.setup-panel{border:1px solid var(--line);background:#f0f1e8;border-radius:5px;padding:28px}.setup-panel h2{font-size:23px;line-height:1.6;margin-top:10px}.choice-row{display:flex;align-items:center;gap:12px;padding:13px 0;border-bottom:1px solid #d9ddcf;font-size:13px;cursor:pointer}.choice-row small{display:block;color:var(--muted);font-size:10px;margin-top:5px}.field-label{display:block;font-size:12px;margin:23px 0 9px}.session-options label{display:flex;align-items:center;gap:7px;font-size:12px;margin:14px 0}.setup-panel .start-solo,.setup-panel .ready-duel{width:100%;margin:20px 0 15px;justify-content:space-between}.small{font-size:11px;line-height:1.9}.muted{color:var(--muted)}.personal-best{border-top:1px solid #d3d9c8;margin-top:25px;padding-top:18px;display:grid;grid-template-columns:1fr auto}.personal-best>span{font-size:11px}.personal-best strong{font-family:Georgia,serif;font-size:28px;grid-row:span 2}.personal-best small{font-size:9px;color:var(--muted);margin-top:6px}.solo-stage{border:1px solid var(--line);background:var(--white);border-radius:5px;padding:26px 32px;text-align:center;min-height:650px;align-self:start}.waiting-label{display:flex;align-items:center;justify-content:center;gap:9px;font-size:11px;color:var(--muted);border-bottom:1px solid var(--line);padding-bottom:20px}.status-dot{width:6px;height:6px;background:#75915c;border-radius:50%}.solo-preview-heading{margin:34px 0 8px}.solo-preview-heading h2{font-size:25px;margin-top:12px}.preview-answer{font-size:13px;margin:20px 0 8px}.preview-answer strong{font-size:21px;font-family:Georgia,serif}.game-topbar{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line);padding-bottom:18px;font-size:12px;gap:10px}.game-score strong{font-size:21px;font-family:Georgia,serif;padding:0 3px}.timer{color:var(--red)}.timer strong{font-size:20px}.question-area{padding-top:25px}.question-text{font-family:Georgia,var(--serif);font-size:45px;margin:12px 0 8px}.question-text>span{font-size:32px;color:#7d856e}.game-feedback{font-size:12px;line-height:1.8;min-height:44px;padding:12px 0}.correct{color:#416d2d!important}.wrong{color:#ae4937!important}.game-actions{display:flex;align-items:center;justify-content:space-between;gap:12px;border-top:1px solid var(--line);padding-top:18px}.end-solo{display:block;margin:15px auto 0;color:var(--muted);font-size:10px}.read-entry{max-width:350px;margin:15px auto 0;display:grid;grid-template-columns:80px 1fr;align-items:center;gap:12px}.read-entry label{font-size:12px}.read-entry input{text-align:center;font-size:24px;padding:7px}.keypad-host{grid-column:1/-1}.number-pad{display:grid;grid-template-columns:repeat(6,1fr);gap:5px}.number-pad button{background:#efefe5;min-height:38px;font-size:14px;border-radius:3px}.number-pad button:hover{background:#e0e5d4}.number-pad button[data-key="清除"]{font-size:10px}.result-screen{padding-top:28px}.result-screen h2{font-size:29px;margin:18px 0}.result-number{font-family:Georgia,serif;font-size:115px;line-height:1.4}.result-number small{font:12px var(--sans);margin-left:15px}.result-stats{display:flex;justify-content:space-evenly;margin:20px 0 35px;border-block:1px solid var(--line);padding:22px 0}.result-stats>span{font-size:11px;color:var(--muted)}.result-stats strong{display:block;font-family:Georgia,serif;font-size:25px;color:var(--ink);margin-top:12px}.answer-review{text-align:left;margin-top:32px}.answer-review summary{font-size:12px;cursor:pointer;padding:15px 0}.table-scroll{overflow:auto}table{width:100%;border-collapse:collapse;font-size:11px}td,th{text-align:left;border-bottom:1px solid var(--line);padding:12px 6px;white-space:nowrap}th{color:var(--muted);font-weight:400}
.duel-setup-layout{display:grid;grid-template-columns:minmax(0,1fr) 360px;gap:40px}.duel-intro{background:#eceee2;border:1px solid #d9decd;border-radius:5px;padding:30px;display:flex;flex-direction:column;align-items:center}.device-illustration{width:240px;background:#f9f8f1;border:7px solid #313a2d;outline:1px solid #1f2a19;border-radius:20px;overflow:hidden;margin:25px 0 35px;box-shadow:14px 15px 0 #d9ddcb}.mini-player{height:172px;padding:15px;text-align:center;display:flex;flex-direction:column;align-items:center;justify-content:center}.mini-player.top{transform:rotate(180deg);background:#e6ecde}.mini-player span{font-size:11px}.mini-player strong{font:23px Georgia,serif;margin-top:7px}.mini-beads{color:#a36441;font-size:19px;line-height:1.1;letter-spacing:13px;border:5px solid #71513b;margin-top:12px;padding:7px 0 7px 12px}.mini-divider{text-align:center;background:var(--ink);color:#e4e8d8;font-size:8px;padding:7px}.duel-rules{display:flex;justify-content:space-between;gap:25px;width:100%;max-width:520px;border-top:1px solid #cbd1be;padding-top:22px}.duel-rules>div{display:flex;gap:13px;align-items:start}.duel-rules span{font:20px Georgia,serif;color:#8d9879}.duel-rules p{font-size:11px;line-height:1.9}.rule-note{padding:17px;background:#e4e8d9;margin-top:23px;border-left:2px solid #a9b98a}.rule-note strong{font-size:12px}.rule-note p{font-size:11px;line-height:1.9;color:var(--muted);margin-top:8px}
.in-duel{overflow:hidden;background:#eff0e5}.in-duel .site-header,.in-duel .site-footer{display:none}.in-duel main{max-width:none;padding:0;height:100dvh;height:100svh;min-height:0}.duel-arena{height:100%;display:grid;grid-template-rows:minmax(0,1fr) 32px minmax(0,1fr);max-width:1000px;margin:auto}.player-panel{display:flex;flex-direction:column;align-items:stretch;min-height:0;padding:12px max(18px,env(safe-area-inset-right)) 12px max(18px,env(safe-area-inset-left));background:#f9f8f0;gap:4px;overflow:hidden;touch-action:none}.player-top{transform:rotate(180deg);background:#edf1e5;border-top:4px solid #68804f}.player-bottom{border-top:4px solid #b97150}.player-heading{display:flex;align-items:center;justify-content:space-between;gap:15px;width:100%;max-width:630px;margin:0 auto;font-size:13px;min-height:26px}.player-name{font-weight:700;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:75%}.player-score{font:25px Georgia,serif;white-space:nowrap}.player-score small{font:10px var(--sans);color:var(--muted)}.duel-question{display:flex;align-items:center;justify-content:center;gap:20px;min-height:41px}.duel-instruction{font-size:11px;color:var(--muted)}.duel-problem{font:34px Georgia,serif;line-height:1.2}.duel-board{flex:1;min-height:0;max-width:610px;display:flex;align-items:center;justify-content:center}.duel-board .abacus{width:100%;height:100%;overflow:hidden}.player-feedback{text-align:center;font-size:11px;line-height:1.5;min-height:18px}.player-actions{display:flex;gap:12px;width:100%;max-width:580px;margin:0 auto}.player-actions .button{min-height:42px;padding:10px 18px;font-size:12px}.player-actions .player-confirm{flex:1}.player-actions .player-clear{width:30%}.player-top .button-primary{background:#405631}.player-bottom .button-primary{background:#965138}.arena-divider{background:#132a13;color:#e9eddf;display:flex;align-items:center;justify-content:space-between;padding:0 20px;font-size:10px;letter-spacing:.05em}.exit-duel{color:#e9eddf;min-height:32px;font-size:10px;padding:4px 0}.round-winner{background:#e2ebd2}.duel-result{display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;height:100%;gap:14px}.duel-result h2{font-size:clamp(23px,4vw,36px)}.duel-final-score{font:72px Georgia,serif;line-height:1.2}.duel-final-score span{color:#9ca58e;margin:0 15px}.duel-result p:not(.eyebrow){font-size:12px}.result-actions{display:flex;gap:20px;align-items:center;margin-top:8px}.rotate-gate{display:none}.rotate-icon{font-size:70px;margin-bottom:25px}
@media(min-width:1600px){.page-intro{padding-top:60px;padding-bottom:45px}.learn-layout{grid-template-columns:250px minmax(0,1fr) 200px;gap:32px}}
@media(max-width:1200px){.site-header{padding-inline:30px}.header-note{display:none}main{padding-inline:30px}.learn-layout{grid-template-columns:210px minmax(0,1fr);gap:24px}.lesson-notes{grid-column:2;display:grid;grid-template-columns:1fr 1fr;column-gap:25px;border-top:1px solid var(--line);padding-top:22px}.lesson-notes .note-mark{grid-column:1/-1}.lesson-notes h3{grid-column:1;margin-top:13px}.lesson-notes .lesson-note{grid-column:1;min-height:0}.bead-legend{grid-column:2;grid-row:2/4;margin:14px 0 0;padding:12px 0}.touch-tip{grid-column:1;margin-top:18px}.touch-tip p br{display:none}.practice-link{grid-column:2;align-self:end;margin-bottom:2px}.site-footer{margin-inline:30px}.solo-layout{grid-template-columns:275px minmax(0,1fr);gap:24px}.setup-panel{padding:23px}.solo-stage{padding:24px}.duel-setup-layout{grid-template-columns:minmax(0,1fr) 330px;gap:24px}.duel-rules{gap:15px}.duel-rules>div{display:block}.duel-rules span{display:block;margin-bottom:7px}}
@media(max-width:850px){.site-header{padding:0 22px;height:86px;gap:10px}.brand{font-size:19px}.brand svg{width:32px}.brand small{font-size:7px}.main-nav{gap:0}.main-nav a{font-size:12px;padding:0 11px;gap:5px}.main-nav a span{font-size:8px}.main-nav a[aria-current]:after{left:11px;right:11px}main{padding-inline:22px}.page-intro{padding:34px 0 29px}.page-intro h1{font-size:34px}.intro-description{font-size:12px}.learn-layout{grid-template-columns:165px minmax(0,1fr);gap:18px}.lesson-link{padding:15px 7px;gap:8px;font-size:11px;min-height:72px}.lesson-link small{font-size:9px}.lesson-arrow{display:none}.section-heading{font-size:11px}.section-heading span+span{font-size:8px}.lesson-copy{padding:20px 20px 0}.lesson-copy h2{font-size:21px}.board-topline{padding:13px 18px}.board-topline .eyebrow{font-size:9px}.value-toggle{font-size:10px}.teaching-board{padding:10px 4px 0}.board-readout{margin:8px 18px 0;gap:12px}.board-readout>span{font-size:9px}.demo-strip{padding:12px 18px}.demo-strip .button{font-size:11px;padding:11px 13px}.step-navigation{gap:7px}.icon-button{width:33px;height:33px}.step-caption{padding:0 18px 17px}.sidebar-note p{font-size:15px}.solo-layout{grid-template-columns:230px minmax(0,1fr);gap:18px}.setup-panel{padding:19px}.setup-panel h2{font-size:21px}.solo-stage{padding:20px 15px;min-height:580px}.question-text{font-size:37px}.game-actions{flex-wrap:wrap;gap:6px}.game-actions .button-primary{flex:1}.duel-setup-layout{grid-template-columns:minmax(0,1fr) 300px;gap:20px}.duel-intro{padding:24px 15px}.duel-rules{gap:10px}.duel-rules p{font-size:10px}.site-footer{margin-inline:22px;font-size:9px}.site-footer span:last-child{display:none}}
@media(max-width:620px){.site-header{height:auto;min-height:116px;padding:17px 18px 0;flex-direction:column;gap:14px}.brand{align-self:flex-start}.main-nav{width:100%;justify-content:space-between;min-height:44px}.main-nav a{padding:0 10px;font-size:12px}.main-nav a[aria-current]:after{left:10px;right:10px}main{padding:0 16px 30px}.page-intro{padding:28px 0 25px}.page-intro h1{font-size:29px;margin:9px 0 12px;letter-spacing:0}.intro-description{font-size:12px;line-height:1.8}.intro-seal{font-size:15px;flex:none;margin:0 0 0 3px;padding:5px}.eyebrow{font-size:8px}.learn-layout{display:flex;flex-direction:column;gap:16px}.lesson-sidebar{width:100%}.section-heading{padding-bottom:10px;margin-bottom:8px}.lesson-list{display:flex;overflow:auto;gap:7px;padding-bottom:4px;scrollbar-width:thin}.lesson-link{width:147px;flex:none;min-height:66px;padding:12px 10px;border:1px solid var(--line);border-radius:4px;gap:8px}.lesson-link.active{margin-top:0}.lesson-link small{font-size:8px}.sidebar-note{display:none}.learning-workspace{width:100%}.lesson-copy{padding:18px 18px 0}.lesson-copy p{min-height:0}.teaching-board{padding:8px 4px 0}.board-readout{padding:13px 0}.board-readout output{font-size:28px}.demo-strip{padding:12px 18px}.step-caption{min-height:68px}.lesson-notes{width:100%;grid-template-columns:1fr 1fr;gap:0 22px;padding:14px 5px 0}.lesson-notes h3{font-size:21px}.lesson-note{font-size:11px;line-height:1.9}.bead-legend{gap:14px;font-size:10px}.touch-tip p{font-size:10px}.practice-link{font-size:10px}.site-footer{margin-inline:16px;padding-top:20px;font-size:8px;gap:10px;letter-spacing:0}.solo-layout{display:flex;flex-direction:column;gap:18px}.setup-panel{width:100%;padding:20px}.setup-panel h2{font-size:23px}.kind-options{display:flex;flex-wrap:wrap;gap:8px}.kind-options legend{width:100%;padding-top:0;margin-bottom:0}.choice-row{flex:1;border:1px solid #cdd3bf;border-radius:4px;min-width:85px;padding:11px 5px;gap:4px;font-size:10px}.choice-row small{display:none}.choice-row input{width:14px;height:14px;margin:0 3px}.session-options{display:flex;gap:20px}.session-options legend{margin-bottom:0}.setup-panel .start-solo{margin-top:12px;margin-bottom:9px}.personal-best{display:none}.solo-stage{width:100%;padding:20px 13px;min-height:0}.solo-preview-heading{margin:25px 0 8px}.solo-preview-heading h2{font-size:23px}.question-area{padding-top:20px}.game-actions .button{font-size:11px;padding-inline:13px}.result-screen{padding:10px 5px 20px}.result-screen h2{font-size:25px}.result-number{font-size:85px}.duel-setup-layout{display:flex;flex-direction:column-reverse;gap:18px}.duel-config{padding:22px}.duel-intro{padding:23px 20px}.duel-rules{justify-content:space-around}.duel-rules p{font-size:11px}.device-illustration{width:210px}.mini-player{height:150px}.duel-result{gap:8px}.duel-final-score{font-size:54px}.duel-result h2{font-size:24px}.duel-result .button{font-size:11px}.player-panel{padding:7px 12px;gap:2px}.player-heading{font-size:11px;min-height:23px}.player-score{font-size:22px}.duel-question{gap:10px;min-height:33px}.duel-instruction{font-size:9px}.duel-problem{font-size:27px}.player-feedback{font-size:9px;min-height:16px}.player-actions{gap:8px}.player-actions .button{min-height:37px;padding:8px 12px;font-size:11px}.arena-divider{padding-inline:14px;font-size:9px}.duel-arena{grid-template-rows:minmax(0,1fr) 28px minmax(0,1fr)}}
@media(orientation:landscape){.in-duel .rotate-gate{position:fixed;inset:0;background:var(--paper);z-index:20;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:25px}.rotate-gate h2{font-size:28px;line-height:1.6}.rotate-gate p{font-size:14px;line-height:1.9;margin:20px 0 25px}.in-duel .duel-arena{visibility:hidden}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}
.principle-strip{margin:18px 28px 4px;padding:12px 15px;border-left:2px solid #b7c39b;background:#f1f3e9;display:flex;align-items:baseline;gap:12px;flex-wrap:wrap}.principle-strip>span{font-size:10px;color:var(--muted);flex:none}.principle-equation{font:18px/1.6 Georgia,var(--serif);overflow-wrap:anywhere}.detailed-learn .teaching-board{max-width:660px;padding-top:4px}.bead-action-panel{margin:0 28px 18px;padding:17px 0 0;border-top:1px solid var(--line)}.action-heading{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.phase-label{font-size:9px;letter-spacing:.05em;color:#687750;flex:none;padding:5px 7px;background:#ecf0e1;border-radius:2px}.action-title{font:600 13px/1.7 var(--sans);flex:1;min-width:80px}.action-change{font:22px Georgia,serif}.action-change.add{color:#4c6c2e}.action-change.subtract{color:#a24b36}.action-equation{display:block;font:28px/1.6 Georgia,var(--serif);margin-top:9px}.bead-action-panel .step-caption{padding:0;min-height:50px;background:transparent;font-size:12px;line-height:1.9;color:#59634d;margin-top:6px}.detailed-learn .demo-strip{flex-wrap:wrap;gap:12px}.detailed-learn .step-navigation{margin-left:auto}.speed-label{display:flex;align-items:center;gap:6px;font-size:10px;color:var(--muted)}.speed-label select{font-size:11px;width:76px;min-height:38px;padding:7px 8px;background:var(--white)}.step-tools{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:9px 28px 0}.step-tools>span{font-size:9px;color:var(--muted)}.step-track{display:flex;flex-wrap:wrap;gap:7px;padding:9px 28px 22px}.step-track button{border:1px solid #d5dcca;border-radius:3px;background:#f6f7ef;min-width:37px;min-height:37px;padding:7px;font-size:11px}.step-track button.active{background:var(--ink);border-color:var(--ink);color:var(--paper)}.step-track button:hover:not(.active){background:#e5ecd8}.teaching-board .bead.is-demo-target .bead-shape{stroke:#e6ae42;stroke-width:4;filter:drop-shadow(0 0 3px #e0ad4d80)}.rod-summary{display:grid;grid-template-columns:1fr auto;gap:10px 8px;border-top:1px solid var(--line);padding-top:17px;margin-top:18px}.rod-summary>span{font-size:10px;color:var(--muted)}.rod-summary strong{font-size:11px;font-weight:500}.motion-key{width:24px;height:14px;border:2px solid #d5a23d;border-radius:50%;display:inline-block}.detailed-learn .lesson-note{min-height:0}.detailed-learn .lesson-notes .rod-summary{grid-column:1/-1}
@media(max-width:850px){.principle-strip{margin:15px 18px 0;padding:10px 12px;gap:6px}.principle-equation{font-size:16px}.bead-action-panel{margin:0 18px 15px}.action-title{font-size:12px}.action-equation{font-size:26px}.detailed-learn .demo-strip{padding:12px 18px;gap:10px}.detailed-learn .step-navigation{gap:5px}.detailed-learn .demo-strip .button{padding-inline:12px}.speed-label select{width:67px}.step-tools{padding-inline:18px}.step-track{padding:7px 18px 18px}.step-tools>span{font-size:8px}}
@media(max-width:620px){.principle-equation{font-size:16px}.principle-strip{gap:4px 10px}.action-title{font-size:12px}.phase-label{font-size:8px}.bead-action-panel .step-caption{font-size:11px;min-height:55px}.action-equation{font-size:25px}.detailed-learn .demo-strip{gap:8px}.detailed-learn .demo-strip .button{font-size:10px;min-height:41px;padding:10px}.speed-label{font-size:9px;gap:4px}.speed-label select{width:61px;font-size:10px}.detailed-learn .step-navigation{gap:4px}.detailed-learn .icon-button{width:29px;height:29px}.step-count{font-size:10px;min-width:29px}.step-track button{min-width:35px;min-height:38px}.step-tools>span{max-width:115px;text-align:right}.detailed-learn .lesson-notes .rod-summary{grid-column:1/-1}}
.detailed-learn .bead-action-panel{border-top:0;margin-bottom:0;padding-top:12px}.detailed-learn .bead-action-panel .step-caption{min-height:0}.detailed-learn .principle-strip{margin-bottom:14px}.detailed-learn .teaching-board{max-width:600px}.abacus[data-scripted=true] .bead{transition:none}