*{box-sizing:border-box}html{color-scheme:light;background:#faf8f2;color:#153b31;font:18px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}body{margin:0}header,nav,main,footer{max-width:840px;margin:auto;padding:20px 28px}header{display:flex;justify-content:space-between;align-items:center;gap:16px}a{color:#0b624b;text-underline-offset:4px}a:hover{color:#b9322b}a:focus-visible{outline:3px solid #b9322b;outline-offset:4px}.brand{display:flex;gap:7px;align-items:center;text-decoration:none;font-size:25px;font-weight:750;white-space:nowrap}.brand span{color:#b9322b}.brand img{margin-right:2px}nav,footer{display:flex;flex-wrap:wrap;gap:8px 24px;border-top:1px solid #d8d9d0}nav a,footer a{padding:6px 0}main{padding-top:32px;padding-bottom:56px}h1{font-size:clamp(2.2rem,6vw,3.6rem);letter-spacing:-.045em;line-height:1.12;margin:0 0 24px}h2{font-size:1.4rem;line-height:1.3;margin:38px 0 12px;letter-spacing:-.015em}p,ul,ol,dl{margin:0 0 20px}li{padding-left:3px;margin:8px 0}.lead{font-size:1.3rem;line-height:1.5}.eyebrow{font-size:.8rem;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:#596b62}.button{display:inline-block;background:#0b624b;color:white;text-decoration:none;border-radius:14px;padding:12px 20px;font-weight:650}.button:hover{background:#153b31;color:white}.small{font-size:1rem;padding:8px 20px}.notice{background:#f9e5e9;border:1px solid #d99ca9;border-radius:16px;padding:20px;margin:0 0 32px}.notice strong{display:block;margin-bottom:6px}dt{font-weight:700;margin-top:20px}dd{margin:4px 0 0}.table-scroll{overflow-x:auto}table{width:100%;border-collapse:collapse;text-align:left;font-size:.95rem}caption{text-align:left;font-weight:650;padding:12px 0}td,th{border-bottom:1px solid #d8d9d0;padding:12px 8px}.skip{position:absolute;left:16px;top:-100px;background:#fff;padding:12px;z-index:3}.skip:focus{top:10px}footer{font-size:.9rem;padding-bottom:36px}@media(max-width:480px){header,nav,main,footer{padding-left:20px;padding-right:20px}.brand{font-size:22px}.brand img{width:30px;height:30px}nav{gap:4px 18px;font-size:.95rem}main{padding-top:24px}h2{margin-top:30px}header{padding-top:16px;padding-bottom:16px}}
.mobile-guides{display:none;max-width:840px;margin:auto;padding:0 20px}.mobile-guides summary{cursor:pointer;list-style:none;padding:12px 0;color:#0b624b;font-weight:650}.mobile-guides summary::-webkit-details-marker{display:none}.mobile-guides summary:focus-visible{outline:3px solid #b9322b;outline-offset:2px}.mobile-guides nav{padding:8px 0 16px;display:flex;flex-direction:column;gap:0}.mobile-guides a{padding:10px 0}@media(max-width:600px){.desktop-guides{display:none}.mobile-guides{display:block;border-top:1px solid #d8d9d0}}

.hand-example{margin:24px 0 32px;padding:20px;background:#eef3e9;border:1px solid #d8d9d0;border-radius:18px}.hand-groups{display:flex;flex-wrap:wrap;gap:18px 20px;align-items:start}.tile-set{max-width:100%}.tile-row{display:flex;gap:3px}.tile-row svg{display:block;width:clamp(36px,7vw,52px);height:auto;aspect-ratio:60/85;flex:none}.tile-set p{font-size:.8rem;line-height:1.4;margin:8px 0 0;max-width:210px}.hand-example figcaption{font-size:.95rem;line-height:1.6;margin-top:20px}h3{font-size:1.15rem;line-height:1.4;margin:28px 0 12px}#scoring-examples{scroll-margin-top:20px}@media(max-width:480px){.hand-example{padding:16px}.hand-groups{gap:16px}.tile-row svg{width:38px}}

/* Visual learning hub and rules guides. */
header,.desktop-guides,.mobile-guides,main,footer,.breadcrumbs{max-width:1120px}main>p,main>ol,main>ul,.learn-hero{max-width:75ch}.learn-hero{padding:12px 0 32px}.learn-hero .lead{font-size:1.6rem;line-height:1.35;letter-spacing:-.025em}.guide-actions{display:flex;align-items:center;flex-wrap:wrap;gap:16px 24px;margin:24px 0}.quiet-button{padding:12px 0;font-weight:650}.rule-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px;margin:28px 0 36px}.rule-card{display:flex;flex-direction:column;overflow:hidden;position:relative;border:1px solid #d8d9d0;border-radius:24px;text-decoration:none;background:#fffdf7;color:#153b31}.rule-card:hover{color:#153b31;border-color:#0b624b}.rule-art{display:flex;align-items:center;justify-content:center;min-height:150px;background:#e6eee1}.chinese-official .rule-art{background:#f9e4e9}.japanese-riichi .rule-art{background:#e6edf3}.american .rule-art{background:#f6edda}.rule-art .tile-row{transform:rotate(-7deg)}.chinese-official .rule-art .tile-row{transform:rotate(6deg)}.american .rule-art .tile-row{transform:rotate(4deg)}.rule-art .tile-row svg{width:48px}.rule-card-copy{padding:20px;display:flex;flex-direction:column;flex:1}.rule-card .eyebrow{font-size:.65rem;letter-spacing:.025em;margin:0 0 10px;min-height:2.8em}.rule-card h3{font-size:1.35rem;margin:0 0 16px;line-height:1.15;letter-spacing:-.03em;min-height:2.3em}.rule-card p:not(.eyebrow){font-size:.88rem;line-height:1.6;flex:1}.rule-status{font-size:.72rem;font-weight:650;padding:4px 9px;border-radius:30px;background:#eef1e8;width:max-content;color:#425d52}.hong-kong .rule-status{background:#0b624b;color:#fff}.card-arrow{position:absolute;right:19px;bottom:21px;color:#0b624b}.breadcrumbs{display:flex;border:0;padding-top:14px;padding-bottom:0;gap:8px;font-size:.8rem;color:#596b62}.breadcrumbs a{padding:0}.basics-section{margin-top:56px;border-top:1px solid #d8d9d0;padding-top:20px;scroll-margin-top:16px}.guide-note{border-left:3px solid #0b624b;padding:10px 18px;background:#eef3e9;color:#425d52}.rule-facts{display:flex;flex-wrap:wrap;gap:20px 40px;margin:32px 0}.rule-facts span{display:flex;align-items:baseline;gap:10px;color:#596b62}.rule-facts strong{font-size:2rem;line-height:1.2;letter-spacing:-.04em;color:#0b624b}.pass-diagram{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:24px 0 36px}.pass-diagram span{background:#f9e4e9;padding:20px;border-radius:16px;font-size:.85rem}.pass-diagram b{display:block;font-size:1.25rem;color:#0b624b}.scoring-sheet{display:grid;grid-template-columns:1fr 1fr;gap:36px;align-items:start;background:#eaf0e4;border:1px solid #d8d9d0;border-radius:24px;padding:32px;margin:48px 0}.scoring-sheet h2{margin-top:0;font-size:1.9rem;letter-spacing:-.035em}.scoring-sheet .eyebrow{margin-bottom:12px}.sheet-preview{display:block;line-height:0;border-radius:14px;overflow:hidden;box-shadow:0 8px 24px #153b3112}.sheet-preview img{display:block;width:100%;height:auto}.sources{border-top:1px solid #d8d9d0;margin-top:40px;padding-top:10px;font-size:.85rem;color:#596b62}.sources h2{font-size:1rem}.table-scroll:focus-visible{outline:3px solid #b9322b;outline-offset:4px}table caption{line-height:1.5}th[scope="row"]{font-weight:600}.hand-example>.tile-row{flex-wrap:wrap}.rule-grid+.table-scroll table{min-width:850px}.rule-grid+.table-scroll tbody th{background:#faf8f2;position:sticky;left:0;min-width:130px}.hand-example .hand-groups{gap:24px}@media(max-width:950px){.rule-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.rule-card h3,.rule-card .eyebrow{min-height:0}.rule-art{min-height:130px}.scoring-sheet{gap:24px;padding:24px}}@media(max-width:600px){.rule-grid{grid-template-columns:1fr}.rule-card{display:grid;grid-template-columns:120px minmax(0,1fr)}.rule-art{min-height:100%}.rule-art .tile-row{flex-wrap:wrap;max-width:95px;justify-content:center}.rule-art .tile-row svg{width:40px}.rule-card h3{font-size:1.2rem}.rule-card .eyebrow{font-size:.62rem}.rule-card p:not(.eyebrow){margin-bottom:14px}.rule-card-copy{padding:18px}.scoring-sheet{grid-template-columns:1fr;padding:20px}.scoring-sheet h2{font-size:1.6rem}.sheet-preview{max-width:480px;width:100%;margin:auto}.pass-diagram{gap:8px}.pass-diagram span{padding:14px 10px}.pass-diagram b{font-size:1.05rem}.rule-facts{gap:16px 24px}.rule-facts strong{font-size:1.7rem}.learn-hero .lead{font-size:1.35rem}}
@media(prefers-reduced-motion:no-preference){.rule-card{transition:border-color .15s,box-shadow .15s}.rule-card:hover{box-shadow:0 8px 24px #153b3110}}

/* Shared public navigation, including the account entry. */
.site-header{max-width:1280px;position:relative;gap:24px;min-height:84px}.site-header nav{padding:0;margin:0;border:0;max-width:none;align-items:center;font-size:16px}.site-header .site-desktop{display:flex;margin-left:auto}.site-header .site-desktop>a{text-decoration:none;padding:10px}.site-mobile{display:none}.language{position:relative}.language summary,.site-mobile summary{cursor:pointer;padding:10px;min-width:44px;list-style:none}.language>div,.site-mobile nav,.account-popover{position:absolute;background:#fffdf8;border:1px solid #d8d9d0;box-shadow:0 12px 40px #153b3118;border-radius:18px;padding:16px;z-index:20;right:20px;top:70px;min-width:240px}.language>div{top:48px;right:0;width:300px}.language span,.language strong,.site-mobile nav a,.site-mobile nav>span{display:block;padding:8px}.language span,.muted{color:#596b62}.site-mobile nav{display:block}.account-entry{position:relative}.account-entry summary{display:flex;align-items:center;gap:10px;cursor:pointer;list-style:none;min-height:44px;font-size:16px}.account-avatar{display:grid;place-items:center;width:42px;height:42px;border-radius:50%;background:#f3b6c6;font-weight:700}.account-popover{top:54px;right:0}.account-popover a,.account-popover button{display:block;padding:12px;width:100%;text-align:left;font:inherit;color:#153b31;background:transparent;border:0;border-radius:8px}.account-popover button{cursor:pointer}.account-popover a:hover,.account-popover button:hover{background:#eef2eb}.account-popover p{margin:0 12px 8px;font-size:15px}.site-header summary:focus-visible,.site-header button:focus-visible{outline:3px solid #b9322b;outline-offset:3px}
@media(max-width:900px){.site-header{gap:10px;min-height:76px}.site-header .site-desktop{display:none}.site-mobile{display:block;margin-left:auto}.site-header .brand{font-size:22px}.site-header .brand img{width:30px;height:30px}.account-entry .account-rating{display:none}.site-header .button{font-size:15px;padding:8px 14px}}

.language summary{display:flex;align-items:center;gap:7px}.language summary>span{display:inline;padding:0;color:#153b31}.language-icon{fill:none;stroke:currentColor;stroke-width:1.5;flex:none;vertical-align:middle}.mobile-language{display:flex;align-items:center;gap:8px}
.site-footer{max-width:1280px;width:100%;font-size:15px;gap:12px 24px}.site-footer a{text-decoration:none}
.app-page #game-app{position:relative;width:100%;height:calc(100svh - 84px);min-height:420px;overflow:hidden}
.app-page.full-game #game-app{height:100dvh;min-height:0}.app-page.full-game>.site-header,.app-page.full-game>.site-footer{display:none}
@media(max-width:900px){.app-page #game-app{height:calc(100svh - 76px)}}

.app-page #game-app{min-height:200px}.app-page.full-game #game-app{min-height:0}

.app-dialog>.site-header,.app-dialog>.site-footer{position:relative;pointer-events:none}.app-dialog>.site-header:after,.app-dialog>.site-footer:after{content:"";position:absolute;inset:0;background:rgba(0,0,0,.54);z-index:30;pointer-events:none}