@charset "UTF-8";
:root{--navy:#173259;--blue:#2364df;--paper:#f2f5fb;--ink:#20324d;--muted:#6a7890;--red:#d94f62;--green:#18866a;--border:#dce4ef}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.65 Thonburi,"Noto Sans Thai",-apple-system,BlinkMacSystemFont,sans-serif}
button,input,select{font:inherit}button,a,input,select{ -webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:default;opacity:.35}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #e9a52b;outline-offset:3px}
button{border:0}a{color:var(--blue)}.topbar{height:88px;background:#fff;border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;padding:0 32px}
.brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--navy);font-size:22px;font-weight:750;line-height:1.3}
.brand-piece{font-size:48px;line-height:1;color:var(--blue)}.brand small{display:block;font-size:12px;font-weight:500;color:var(--muted);margin-top:5px}.header-actions{display:flex;gap:18px;align-items:center}.progress-label{font-size:14px;color:var(--muted)}
.icon-button{width:34px;height:34px;border:1px solid var(--border);border-radius:50%;background:#fff;color:var(--navy);font-weight:700}
.lang-switch{display:flex;padding:3px;gap:2px;background:#e7edf6;border-radius:8px}.lang-switch button{font-size:12px;min-width:39px;padding:4px 7px;border-radius:5px;background:transparent;color:var(--muted)}.lang-switch button.active{background:var(--navy);color:#fff}
.app{display:grid;grid-template-columns:230px minmax(0,1fr);max-width:1510px;margin:auto;gap:30px;padding:30px 30px 50px}
.sidebar{padding-right:2px}.rail-title{display:flex;justify-content:space-between;align-items:center;margin-bottom:18px}.rail-title h2{font-size:18px;margin:0}.rail-title>span{font-size:12px;color:var(--muted)}
.filters{display:flex;gap:3px;margin-bottom:16px;padding:4px;background:#e7edf6;border-radius:9px}.filters button{flex:1;background:transparent;color:var(--muted);padding:6px 4px;border-radius:6px;font-size:12px}.filters button.active{background:#fff;color:var(--navy);box-shadow:0 2px 6px #1732590c}
.match-card{width:100%;text-align:left;padding:16px 14px;margin:0 0 8px;border-radius:10px;background:transparent;position:relative;color:var(--ink);border:1px solid transparent;transition:background .15s}
.match-card:hover{background:#e8eef8}.match-card.active{background:var(--navy);color:#fff}.match-card .result-row{display:flex;align-items:center;gap:7px;font-size:11px;color:var(--muted);margin-bottom:7px}.match-card.active .result-row{color:#b8c9e3}.result-dot{width:7px;height:7px;border-radius:50%;background:var(--red);display:inline-block}.result-dot.win{background:#33aa86}.match-card .match-title{display:block;font-size:15px;font-weight:650;line-height:1.5}.match-card .opponent{display:block;font-size:12px;margin-top:7px;opacity:.7;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.done-check{margin-left:auto;font-size:13px;color:#40c69a}.rail-note{color:var(--muted);font-size:13px;padding:10px 14px}
.workspace{min-width:0}.lesson-heading{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:20px}.match-meta{font-size:12px;color:var(--muted);margin:0 0 5px}.lesson-heading h1{font-size:clamp(24px,2.2vw,32px);line-height:1.45;letter-spacing:-.5px;margin:0;font-weight:750}
.quiet-button{color:var(--blue);background:transparent;padding:8px 10px;border-radius:6px;white-space:nowrap}.quiet-button:hover{background:#e5edfc}#flip-button{font-size:13px}
.mode-tabs{display:flex;gap:0;border-bottom:1px solid var(--border);margin-bottom:22px}.mode-tabs button{position:relative;background:none;color:var(--muted);padding:11px 20px;font-size:14px;white-space:nowrap}.mode-tabs button.active{color:var(--blue);font-weight:700}.mode-tabs button.active:after{position:absolute;bottom:-1px;left:15px;right:15px;height:3px;background:var(--blue);border-radius:3px;content:""}.mode-tabs button[data-mode=try].active:after{background:var(--green)}.mode-tabs button[data-mode=try].active{color:var(--green)}
.lesson-layout{display:grid;grid-template-columns:minmax(340px,1fr) minmax(245px,300px);gap:28px;align-items:start}.board-column{min-width:0;max-width:620px}.player-bar{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:0 2px 10px;font-size:13px}.player-name{display:flex;gap:8px;align-items:center}.color-token{width:12px;height:12px;display:inline-block;border-radius:50%;background:#fff;border:1px solid #8a98ad;box-shadow:0 1px 2px #0002}.color-token.black{background:#263247;border-color:#263247}.turn-badge{font-size:11px;color:var(--blue);background:#e3ecff;padding:2px 8px;border-radius:5px;white-space:nowrap}.bottom-player{padding:10px 2px 0}.bottom-player #board-instruction{font-size:11px;color:var(--muted);text-align:right}
.board{width:100%;aspect-ratio:1;position:relative;border:5px solid #fff;box-shadow:0 5px 22px #17325915;border-radius:5px;overflow:hidden;user-select:none;touch-action:pan-y}
.board[data-practice=true]{touch-action:none}
.squares{position:absolute;inset:0;display:grid;grid-template-columns:repeat(8,1fr);grid-template-rows:repeat(8,1fr)}.square{position:relative;background:#e9eef6;padding:0;border-radius:0;min-width:0;min-height:0}.square.dark{background:#6e91bf}.square:focus-visible{outline-offset:-4px;z-index:4}
.square.last{box-shadow:inset 0 0 0 100px #e8c34d65}.square.focus{box-shadow:inset 0 0 0 100px #2364df14}.square.selected{box-shadow:inset 0 0 0 100px #f6ca4a9c}
.square.legal:after{content:"";width:23%;height:23%;border-radius:50%;background:#17325950;position:absolute;left:38.5%;top:38.5%;z-index:4}
.square.capture.legal:after{width:82%;height:82%;top:9%;left:9%;border:5px solid #17325955;background:transparent}.square.check{background:radial-gradient(#f16472 5%,#d94f6260 65%,#d94f6210)!important}
.pieces,.arrows,.coordinates{position:absolute;inset:0;pointer-events:none}.piece{position:absolute;left:0;top:0;width:12.5%;height:12.5%;padding:3%;box-sizing:content-box;padding:0;transition:transform .32s ease;z-index:2;will-change:transform}.piece svg{display:block;width:100%;height:100%;padding:5%;filter:drop-shadow(0 2px 1px #0002)}.piece.dragging{opacity:.25}.drag-ghost{position:fixed;pointer-events:none;z-index:100;width:70px;height:70px;filter:drop-shadow(0 7px 5px #0003)}
.coordinates span{position:absolute;font-size:10px;font-weight:700;line-height:1;z-index:5}.coord-file{bottom:3px;transform:translateX(-50%)}.coord-rank{left:3px;transform:translateY(-50%)}.coordinate-dark{color:#314b6c}.coordinate-light{color:#f2f5fb}.arrows{z-index:6;overflow:visible}
.playback-buttons{display:flex;justify-content:center;align-items:center;gap:8px;padding-top:18px}.control-button{width:34px;height:36px;background:transparent;color:var(--navy);border-radius:7px;font-size:23px;line-height:1}.control-button:hover{background:#dfe8f8}.play-button{min-width:144px;height:42px;background:var(--blue);color:#fff;border-radius:9px;font-size:14px;font-weight:650;display:flex;justify-content:center;align-items:center;gap:9px}.play-button:hover{background:#1c54bf}#timeline{width:100%;accent-color:var(--blue);height:18px;margin:12px 0 0;cursor:pointer}.timeline-label{font-size:11px;color:var(--muted);display:flex;justify-content:space-between;align-items:center}.timeline-label label{display:flex;gap:5px;align-items:center}.timeline-label input{accent-color:var(--blue)}
.caption-box{display:flex;gap:12px;align-items:flex-start;background:#fff;border-radius:9px;padding:15px 17px;margin-top:17px;min-height:78px;border:1px solid var(--border)}.caption-box p{margin:0;font-size:16px;line-height:1.65}.caption-box>span{font-size:9px;color:var(--blue);padding-top:8px}.line-origin{font-size:11px;color:var(--muted);margin:9px 3px 0;line-height:1.6}
.coach{background:#fff;border-radius:14px;padding:23px 22px;border:1px solid var(--border)}.coach-label{display:flex;align-items:center;gap:9px;color:var(--muted);font-size:12px;margin-bottom:22px}.coach-avatar{display:grid;place-items:center;background:#e5edfc;color:var(--blue);width:32px;height:32px;border-radius:11px;font-size:24px;line-height:1}.coach h2{font-size:23px;line-height:1.5;letter-spacing:-.3px;margin:0 0 12px}.coach p{font-size:15px;line-height:1.85;margin:0 0 17px}.coach .coach-sub{font-size:12px;color:var(--muted)}.coach .lesson-badge{display:inline-block;font-size:11px;padding:3px 8px;background:#fff0f2;color:#b1384b;border-radius:5px;margin-bottom:10px}.coach .lesson-badge.good{background:#e3f4ed;color:var(--green)}
.coach-actions{display:flex;flex-direction:column;gap:9px;margin-top:18px}.primary-button{background:var(--blue);color:#fff;min-height:45px;border-radius:8px;padding:10px 14px;font-weight:650;font-size:14px}.primary-button.green{background:var(--green)}.secondary-button{border:1px solid var(--border);background:#fff;color:var(--navy);min-height:42px;border-radius:8px;padding:9px 14px;font-size:14px}.secondary-button:hover{background:var(--paper)}.takeaway{margin-top:26px;padding-top:20px;border-top:1px solid var(--border)}.takeaway>span{font-size:11px;color:var(--blue);font-weight:700}.takeaway p{font-size:14px;margin:8px 0 0;color:var(--navy);line-height:1.8}.extra-details{margin-top:22px;font-size:11px;color:var(--muted)}.extra-details summary{cursor:pointer}.extra-details p{font-size:11px;line-height:1.8;margin:10px 0}.extra-details a{font-size:11px}
.feedback{padding:14px 15px;border-radius:9px;margin-top:15px;font-size:14px;line-height:1.8;background:#fff3df;color:#704f19}.feedback.success{background:#e4f4ed;color:#10664f}.feedback b{display:block;font-size:16px;margin-bottom:5px}.hint-box{border-left:3px solid #e9b24b;padding:10px 13px;margin:12px 0;background:#fff7e7;font-size:14px;line-height:1.8}
.lesson-bottom{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-top:25px;padding-top:18px;border-top:1px solid var(--border);font-size:12px;color:var(--muted)}#completion-note{color:var(--green)}.mobile-picker{display:none}
dialog{border:0;border-radius:18px;padding:34px;max-width:560px;width:calc(100% - 32px);color:var(--ink);box-shadow:0 20px 80px #17325940}dialog::backdrop{background:#17325970;backdrop-filter:blur(3px)}dialog h2{font-size:24px;line-height:1.5;margin:5px 0 18px}dialog ol{padding-left:24px}dialog li{margin:12px 0;font-size:15px}dialog p{font-size:14px}.dialog-close{position:absolute;right:15px;top:12px;color:var(--muted);background:transparent;font-size:26px}.help-king{color:var(--blue);font-size:40px}.muted{color:var(--muted);font-size:12px!important}.promotion-buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:9px}.promotion-button{background:var(--paper);border:1px solid var(--border);border-radius:9px;padding:8px;color:var(--ink);font-size:12px}.promotion-button svg{width:100%;height:auto}
@media(min-width:1450px){.app{gap:38px;padding-top:38px}.lesson-layout{gap:38px;grid-template-columns:minmax(340px,620px) minmax(280px,320px)}}
@media(max-width:1180px){.app{grid-template-columns:195px minmax(0,1fr);gap:20px;padding:24px 20px}.lesson-layout{grid-template-columns:minmax(300px,1fr) 250px;gap:18px}.coach{padding:19px 17px}.mode-tabs button{padding:10px 14px}.topbar{padding:0 23px}.lesson-heading h1{font-size:26px}}
@media(max-width:980px){.sidebar{display:none}.app{display:block;max-width:850px}.mobile-picker{display:flex;align-items:center;gap:12px;margin-bottom:20px;font-size:13px;color:var(--muted)}.mobile-picker select{flex:1;min-width:0;padding:9px 11px;border:1px solid var(--border);border-radius:7px;background:#fff;color:var(--ink);font-size:14px}.lesson-layout{grid-template-columns:minmax(300px,1fr) 255px}.lesson-heading h1{font-size:27px}}
@media(min-width:981px) and (max-height:850px){.topbar{height:68px}.app{padding-top:18px}.lesson-heading{margin-bottom:10px}.lesson-heading h1{font-size:25px}.mode-tabs{margin-bottom:14px}.lesson-layout{grid-template-columns:minmax(300px,calc(100dvh - 330px)) minmax(245px,1fr)}.coach{max-width:360px}.board-column{max-width:100%}.match-card{padding:12px 13px}.playback-buttons{padding-top:12px}.caption-box{margin-top:10px}}
@media(max-width:680px){.topbar{height:74px;padding:0 16px}.brand{font-size:19px;gap:8px}.brand-piece{font-size:37px}.brand small{font-size:10px}.header-actions{gap:10px}.progress-label{font-size:11px}.app{padding:20px 14px 32px}.lesson-heading{align-items:flex-start;margin-bottom:14px}.lesson-heading h1{font-size:25px}.match-meta{font-size:11px}#flip-button span{display:none}#flip-button{font-size:22px;padding:3px 8px}.mode-tabs{margin-bottom:16px}.mode-tabs button{flex:1;padding:10px 3px;font-size:12px}.mode-tabs button.active:after{left:5px;right:5px}.lesson-layout{display:block}.board-column{max-width:560px;margin:0 auto}.coach{margin-top:24px;padding:22px}.coach-label{margin-bottom:15px}.coach h2{font-size:23px}.caption-box{min-height:74px;padding:14px}.caption-box p{font-size:15px}.lesson-bottom{font-size:11px}.control-button{width:35px;height:38px}.mobile-picker{margin-bottom:17px}.player-bar{font-size:12px}.bottom-player #board-instruction{font-size:10px}.board{border-width:4px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}.piece{transition:none}}
@media(max-width:680px){.header-actions{gap:8px}.progress-label{display:none}.lang-switch button{min-width:33px;font-size:11px;padding:4px 6px}html[lang=en] .brand{font-size:17px}html[lang=en] .brand small{font-size:10px}html[lang=en] .mode-tabs button{font-size:11px}html[lang=en] .lesson-heading h1{font-size:24px}}