:root{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;color:#293229;background:#f6f5ee;font-synthesis:none}
*{box-sizing:border-box}
body{margin:0;min-width:290px}
button,a{-webkit-tap-highlight-color:transparent}
button{font:inherit;cursor:pointer}
button:focus-visible,a:focus-visible{outline:3px solid #829773;outline-offset:3px}
button:disabled{opacity:.5;cursor:default}
a{color:inherit;text-decoration:none}
.page{min-height:100dvh;max-width:1380px;margin:auto;padding:0 clamp(18px,5vw,70px);display:flex;flex-direction:column}
.site-header{height:100px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #e1e5d8}
.home-brand{display:inline-flex;align-items:center;gap:11px;font-family:Georgia,"Times New Roman",serif;font-size:25px;line-height:1;letter-spacing:-1px}
.home-brand small{display:block;margin-top:6px;color:#8d9886;font-family:-apple-system,BlinkMacSystemFont,"PingFang SC",sans-serif;font-size:9px;letter-spacing:1px}
.brand-symbol{display:inline-flex;align-items:center;justify-content:center;width:42px;height:42px;flex:none;position:relative;overflow:hidden;padding:0 3px 5px 0;border-radius:12px;background:#526447;color:#fff;box-shadow:0 5px 13px #29322918;font-size:31px;font-style:italic}
.brand-symbol i{position:absolute;top:8px;right:8px;width:6px;height:6px;border-radius:50%;background:#d69b77}
.back-link{display:inline-flex;align-items:center;gap:10px;min-height:44px;padding:8px 4px;color:#526447;font-size:13px;font-weight:600}
.back-link:hover{text-decoration:underline}
.back-link span{font-size:20px;line-height:1}
main{flex:1}
.intro{padding:47px 0 36px}
.eyebrow,.panel-label{color:#899a7d;font-size:10px;font-weight:700;letter-spacing:2px}
.intro h1{margin:14px 0 10px;font-size:clamp(31px,4vw,52px);font-weight:560;letter-spacing:1px;line-height:1.25}
.intro h1 span{color:#a96949}
.intro p{margin:0;color:#899185;font-size:13px;line-height:1.8}
.game-layout{display:grid;grid-template-columns:minmax(0,680px) minmax(270px,340px);align-items:start;justify-content:center;gap:clamp(20px,4vw,48px)}
.board-card{min-width:0;padding:23px 23px 18px;border:1px solid #e5e8dd;border-radius:22px;background:#fff;box-shadow:0 18px 55px #2932290b}
.board-topline{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px;color:#6d8062;font-size:12px;font-weight:700;letter-spacing:.3px}
.board-topline span:last-child{color:#9aa695;font-size:11px;font-weight:500}
.board-wrap{position:relative;display:flex;align-items:center;justify-content:center;overflow-anchor:none}
.board{display:grid;grid-template-columns:repeat(15,minmax(0,1fr));grid-template-rows:repeat(15,minmax(0,1fr));width:100%;max-width:630px;aspect-ratio:1;padding:10px;border:1px solid #d4b57d;border-radius:12px;background:#e9c994;box-shadow:inset 0 2px 12px #9b794724,0 8px 20px #6c50221b;touch-action:manipulation;user-select:none;-webkit-user-select:none}
.cell{position:relative;display:block;min-width:0;min-height:0;padding:0;border:0;border-radius:0;background:transparent}
.cell::before,.cell::after{content:"";position:absolute;background:#8f744d;pointer-events:none}
.cell::before{left:0;right:0;top:calc(50% - .5px);height:1px}
.cell::after{top:0;bottom:0;left:calc(50% - .5px);width:1px}
.cell.edge-left::before{left:50%}
.cell.edge-right::before{right:50%}
.cell.edge-top::after{top:50%}
.cell.edge-bottom::after{bottom:50%}
.cell:focus-visible{z-index:3;border-radius:50%;outline:2px solid #526447;outline-offset:-2px}
.cell:not(.occupied):hover{background:#ffffff33;border-radius:50%}
.star-dot{position:absolute;z-index:1;top:50%;left:50%;width:5px;height:5px;border-radius:50%;background:#725939;transform:translate(-50%,-50%);pointer-events:none}
.stone{position:absolute;z-index:2;inset:12%;border-radius:50%;pointer-events:none}
.cell.black .stone,.piece.black{background:radial-gradient(circle at 34% 28%,#555d56,#202722 68%,#111713);box-shadow:inset -2px -3px 4px #0b110b6b,0 2px 4px #3a301c55}
.cell.white .stone,.piece.white{background:radial-gradient(circle at 30% 25%,#fff,#e9e6dc 70%,#c7c2b5);box-shadow:inset -2px -2px 4px #b0a99988,0 2px 4px #3a301c55}
.cell.last .stone::after{content:"";position:absolute;top:50%;left:50%;width:5px;height:5px;border-radius:50%;background:#d69b77;transform:translate(-50%,-50%)}
.cell.winning .stone{box-shadow:0 0 0 3px #c6784b,0 0 14px 4px #e9a87c}
.board-card.victory .board{animation:board-victory 1.35s ease-out}
.board-card.victory .cell.winning .stone{animation:winning-stone .82s ease-out both;animation-delay:calc(var(--win-order,0) * 95ms)}
.celebration{position:absolute;inset:0;z-index:4;width:min(100%,630px);margin:auto;overflow:hidden;border-radius:12px;pointer-events:none}
.celebration[hidden]{display:none}
.confetti{position:absolute;inset:0;overflow:hidden}
.confetti-piece{position:absolute;top:-20px;width:8px;height:14px;border-radius:2px;background:#d69b77;opacity:0;animation:confetti-fall 4.2s linear both;animation-delay:var(--delay,0ms)}
.confetti-piece:nth-child(4n+2){background:#8daa77}
.confetti-piece:nth-child(4n+3){background:#f0d584}
.confetti-piece:nth-child(4n+4){background:#fff4dc}
.win-badge{position:absolute;top:9%;left:50%;display:flex;flex-direction:column;align-items:center;min-width:178px;padding:12px 21px 11px;border:1px solid #f8e0be;border-radius:15px;background:#fffaf0ed;box-shadow:0 10px 28px #6545233b;color:#6a4e2f;text-align:center;transform:translateX(-50%);animation:badge-pop .7s cubic-bezier(.2,1.35,.4,1) both}
.win-badge>span{position:absolute;top:-16px;right:-10px;color:#d69b77;font-size:26px}
.win-badge strong{font-size:17px;white-space:nowrap}
@keyframes winning-stone{0%{transform:scale(1);filter:brightness(1)}42%{transform:scale(1.24);filter:brightness(1.3)}100%{transform:scale(1);filter:brightness(1)}}
@keyframes board-victory{0%,100%{box-shadow:inset 0 2px 12px #9b794724,0 8px 20px #6c50221b}45%{box-shadow:inset 0 2px 12px #9b794724,0 0 0 6px #e4b46d99,0 8px 30px #bd8e56aa}}
@keyframes badge-pop{0%{opacity:0;transform:translate(-50%,-15px) scale(.72)}65%{opacity:1;transform:translate(-50%,3px) scale(1.06)}100%{opacity:1;transform:translate(-50%,0) scale(1)}}
@keyframes confetti-fall{0%{opacity:0;transform:translate3d(0,-20px,0) rotate(0)}8%{opacity:1}85%{opacity:1}100%{opacity:0;transform:translate3d(var(--drift,0px),var(--fall-distance,650px),0) rotate(var(--spin,540deg))}}
.board-hint{margin:16px 0 0;text-align:center;color:#9aa293;font-size:11px;line-height:1.7}
.game-sidebar{display:flex;flex-direction:column;gap:18px}
.panel{padding:24px;border:1px solid #e5e8dd;border-radius:18px;background:#fff;box-shadow:0 10px 35px #29322906}
.panel h2{margin:12px 0 21px;font-size:19px;font-weight:600}
.mode-switch{display:grid;gap:9px}
.mode-button{display:block;width:100%;min-height:69px;padding:13px 15px;border:1px solid #e4e8de;border-radius:11px;background:#fafbf8;color:#53624e;font-size:13px;font-weight:700;text-align:left}
.mode-button small{display:block;margin-top:6px;color:#9ba698;font-size:11px;font-weight:400}
.mode-button.active{border-color:#a6b99c;background:#edf3e8;color:#435a38;box-shadow:inset 3px 0 #6f8a60}
.players{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:18px}
.player{display:flex;align-items:center;gap:10px;min-width:0;padding:11px 8px;border:1px solid #e6e8e1;border-radius:10px;background:#fafbf8;opacity:.65}
.player.active{border-color:#a6b99c;background:#f0f5eb;opacity:1}
.piece{width:24px;height:24px;flex:none;border-radius:50%}
.player strong,.player small{display:block;white-space:nowrap}
.player strong{font-size:12px}
.player small{margin-top:3px;color:#8e9b84;font-size:10px}
.game-status{display:flex;align-items:center;min-height:57px;margin:12px 0 16px;padding:11px 13px;border-radius:10px;background:#f5f6f0;color:#566b4b;font-size:12px;font-weight:600;line-height:1.6}
.game-status.finished{background:#faeee5;color:#a45e3c}
.actions{display:grid;grid-template-columns:1fr 1.2fr;gap:9px}
.actions button{min-height:43px;padding:9px;border:1px solid #dfe5d8;border-radius:9px;background:#fff;color:#526447;font-size:12px;font-weight:700}
.actions button:last-child{border-color:#526447;background:#526447;color:#fff}
.actions button:last-child:hover{background:#3b4f34}
.little-note{display:flex;align-items:center;gap:13px;padding:6px 14px;color:#9ba58f}
.little-note span{font-size:31px;color:#c88762}
.little-note p{margin:0;font-family:Georgia,"Songti SC",serif;font-size:13px;line-height:1.8}
footer{padding:36px 0 22px;text-align:center;color:#afb5aa;font-size:10px}
@media(max-width:920px){.game-layout{grid-template-columns:minmax(0,680px)}.game-sidebar{display:grid;grid-template-columns:1fr 1fr}.little-note{grid-column:1/-1}.intro{padding:34px 0 28px}}
@media(max-width:640px){.page{padding:0 15px}.site-header{height:76px}.home-brand{font-size:21px}.brand-symbol{width:36px;height:36px;font-size:27px}.back-link{font-size:12px}.intro{padding:26px 3px 23px}.intro h1{font-size:32px}.intro p{font-size:12px}.game-sidebar{display:flex;gap:12px}.board-card{padding:12px 10px 11px;border-radius:15px}.board-topline{margin:2px 5px 11px}.board{padding:5px;border-radius:9px}.board-hint{margin-top:10px;font-size:10px}.panel{padding:18px;border-radius:14px}.panel h2{margin-bottom:14px}.mode-switch{grid-template-columns:1fr 1fr}.mode-button{min-height:72px;padding:11px}.mode-button small{line-height:1.35}.game-status{height:72px;min-height:72px}.win-badge{top:7%;min-width:148px;padding:9px 14px}.win-badge strong{font-size:15px}.little-note{display:none}footer{padding-top:26px}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}.board-card.victory .board,.board-card.victory .cell.winning .stone,.win-badge{animation:none!important}}