:root{color-scheme:dark;--bg-gradient:linear-gradient(135deg,#1e3c72,#2a5298 50%,#1e9fab);--board-line:rgba(60,35,13,0.55);--stone-black:radial-gradient(circle at 30% 30%,#4a5568,#111827);--stone-white:radial-gradient(circle at 30% 30%,#ffffff,#d1d5db)}*{box-sizing:border-box}body{margin:0;min-height:100vh;background:var(--bg-gradient);color:#f9fafb;font-family:Pretendard,Noto Sans KR,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;display:flex;flex-direction:column;align-items:center;gap:24px;padding:32px 16px 48px}a{color:inherit;text-decoration:none}main{width:min(100%,960px)}.hero{text-align:center;display:flex;flex-direction:column;gap:8px}.hero h1{font-size:clamp(2.2rem,5vw,3.2rem);margin:0;text-shadow:0 12px 30px rgba(0,0,0,.4)}.hero p{margin:0;opacity:.85}.promo-grid{margin-top:24px;display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:18px}.promo-item{display:block;border-radius:18px;overflow:hidden;background:rgba(15,23,42,.35);box-shadow:0 20px 40px rgba(0,0,0,.28);transition:transform .3s ease,box-shadow .3s ease}.promo-item:hover{transform:translateY(-8px);box-shadow:0 28px 52px rgba(0,0,0,.4)}.promo-item img{display:block;width:100%;height:auto}.game-area{margin-top:32px;background:rgba(15,23,42,.6);backdrop-filter:blur(18px);border-radius:24px;box-shadow:0 24px 60px rgba(15,23,42,.55);padding:28px;display:grid;gap:32px;grid-template-columns:minmax(0,1fr) 320px}.board-wrapper{background:linear-gradient(140deg,#caa56c,#9b6f35);border-radius:20px;box-shadow:inset 0 0 40px rgba(0,0,0,.35),0 18px 30px rgba(0,0,0,.4);padding:22px;position:relative;aspect-ratio:1/1}.board{display:grid;grid-template-columns:repeat(15,1fr);grid-template-rows:repeat(15,1fr);width:100%;height:100%}.cell{position:relative;border:1px solid var(--board-line);background:transparent;display:flex;align-items:center;justify-content:center;cursor:pointer;padding:0;transition:background-color .15s ease}.cell:hover:after{content:"";width:16px;height:16px;border-radius:50%;background:rgba(15,23,42,.45)}.cell:disabled{cursor:not-allowed}.stone{width:82%;height:82%;border-radius:50%;box-shadow:inset 4px 4px 10px rgba(255,255,255,.12),inset -5px -5px 12px rgba(0,0,0,.35),0 10px 20px rgba(0,0,0,.35);animation:pop .22s ease-out}.stone.black{background:var(--stone-black)}.stone.white{background:var(--stone-white);border:1px solid rgba(0,0,0,.12)}@keyframes pop{0%{transform:scale(.3);opacity:0}to{transform:scale(1);opacity:1}}.sidebar{display:flex;flex-direction:column;gap:20px}.status{padding:18px;text-align:center;font-size:1.05rem;font-weight:600;border-radius:18px;background:rgba(79,70,229,.18);border:1px solid rgba(129,140,248,.32)}.reset-btn{padding:14px 20px;border:none;border-radius:14px;font-size:1rem;font-weight:600;cursor:pointer;color:#f9fafb;background:linear-gradient(135deg,#ef4444,#f97316);box-shadow:0 14px 30px rgba(248,113,113,.35);transition:transform .2s ease,box-shadow .2s ease}.reset-btn:hover{transform:translateY(-3px);box-shadow:0 18px 34px rgba(248,113,113,.45)}.rules{padding:18px 20px;border-radius:18px;background:rgba(15,23,42,.5);border:1px solid rgba(148,163,184,.25);display:flex;flex-direction:column;gap:12px}.rules h2{margin:0;font-size:1.12rem}.rules ol{margin:0;padding-left:20px;display:flex;flex-direction:column;gap:8px;color:rgba(226,232,240,.92)}.footer{margin-top:12px;opacity:.8;font-size:.9rem}@media (max-width:900px){.game-area{grid-template-columns:1fr}.board-wrapper,.sidebar{max-width:520px;margin:0 auto}}@media (max-width:640px){body{padding:24px 12px 40px}.promo-grid{grid-template-columns:1fr}.game-area{padding:22px 18px}.status{font-size:.95rem}}