:root{--ink:#253128;--muted:#667169;--forest:#28735a;--forest-dark:#18513e;--cream:#fffdf4;--leaf:#dcebd3;--peach:#f8d8ad;--line:#d7d8c9;--wood:#e6b873}*{box-sizing:border-box}html{scroll-behavior:smooth}body{color:var(--ink);background:radial-gradient(circle at 12% 5%,#ffffffe6 0 8%,#0000 24%),linear-gradient(145deg,#edf4df 0%,#fdf5df 48%,#e7f2e8 100%);min-height:100vh;margin:0;font-family:ui-rounded,Hiragino Maru Gothic ProN,Yu Gothic,sans-serif}button,a{font:inherit}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.48}a{color:inherit}main{width:min(1120px,100% - 32px);margin:0 auto}.site-header{justify-content:space-between;align-items:center;gap:18px;min-height:84px;display:flex}.brand{align-items:center;text-decoration:none;display:inline-flex}.brand img{width:176px;height:auto;display:block}.auth-wrap{justify-items:end;gap:5px;display:grid}.auth-controls{flex-wrap:wrap;justify-content:flex-end;align-items:center;gap:8px;display:flex}.auth-controls button,.reset-button{color:#fff;background:var(--forest);border:1px solid #1d5b46;border-radius:999px;padding:10px 15px;font-weight:800;box-shadow:0 3px #174c3a}.auth-controls .line-button{background:#06c755;border-color:#059744;box-shadow:0 3px #047f39}.auth-controls .quiet-button{color:var(--forest-dark);background:#fff;box-shadow:0 3px #c9d5cc}.auth-wrap small{color:var(--muted);text-align:right;max-width:340px}.signed-in{color:var(--forest-dark);font-size:.88rem;font-weight:800}.hero{background:#fffdf4e6;border:1px solid #28735a38;border-radius:38px;grid-template-columns:minmax(0,1.5fr) minmax(250px,.7fr);align-items:center;min-height:390px;padding:clamp(32px,6vw,72px);display:grid;position:relative;overflow:hidden;box-shadow:0 8px #c8ddbe,0 22px 60px #32503921}.hero h1{letter-spacing:-.055em;margin:12px 0 20px;font-size:clamp(2.4rem,6vw,4.8rem);line-height:1.08}.hero p{max-width:640px;color:var(--muted);margin:0;font-size:1.08rem;line-height:1.9}.hero-logo{width:min(100%,420px);height:auto;margin:-28px 0 10px;display:block}.eyebrow{color:var(--forest);letter-spacing:.08em;font-weight:900}.hero-motif{height:260px;position:relative}.hero-motif span{filter:drop-shadow(0 14px 8px #00000024);border-radius:50%;place-items:center;width:150px;height:150px;font-size:7rem;display:grid;position:absolute}.hero-motif span:first-child{color:#202824;top:5px;left:0}.hero-motif span:nth-child(2){color:#fff;text-shadow:0 0 #333;-webkit-text-stroke:2px #5d655d;bottom:0;right:0}.hero-motif i{color:#5b954e;font-style:normal;font-weight:900;position:absolute;top:10px;right:8px;transform:rotate(15deg)}.section-heading{justify-content:space-between;align-items:end;gap:20px;margin:72px 0 22px;display:flex}.section-heading h2,.coming-soon h2{margin:8px 0 0;font-size:clamp(1.6rem,4vw,2.35rem)}.section-heading p{color:var(--muted)}.catalog-layout{gap:18px;display:grid}.catalog-controls{border:1px solid var(--line);background:#fffdf4db;border-radius:20px;justify-content:space-between;align-items:end;gap:16px;padding:16px 18px;display:flex}.catalog-controls label{color:var(--muted);gap:6px;font-size:.86rem;font-weight:800;display:grid}.catalog-controls select{border:1px solid var(--line);background:#fff;border-radius:12px;min-height:44px;padding:0 38px 0 12px}.problem-list{flex-wrap:wrap;justify-content:flex-end;gap:8px;display:flex}.problem-list button{border:1px solid var(--line);min-height:48px;color:var(--ink);background:#fff;border-radius:14px;gap:2px;padding:8px 14px;display:grid}.problem-list button.selected{color:#fff;border-color:var(--forest-dark);background:var(--forest)}.problem-list span{opacity:.78;font-size:.75rem}.catalog-message{border:1px solid var(--line);background:var(--cream);border-radius:24px;padding:28px;font-weight:800}.catalog-message.error{color:#8a3a27;background:#fde1d5}.member-note{color:var(--forest-dark);background:var(--leaf);border-radius:16px;padding:12px 16px;font-weight:800}.problem-card{border:1px solid var(--line);background:var(--cream);border-radius:32px;grid-template-columns:minmax(240px,.8fr) minmax(320px,1.2fr);align-items:center;gap:clamp(24px,5vw,64px);padding:clamp(24px,5vw,52px);display:grid;box-shadow:0 7px #e2c28f,0 18px 45px #4e40271f}.problem-copy h2{margin:10px 0;font-size:2rem}.problem-copy p{color:var(--muted);line-height:1.8}.difficulty{background:var(--leaf);color:var(--forest-dark);border-radius:999px;padding:6px 11px;font-weight:900;display:inline-block}.feedback{background:#f2f0e3;border-radius:18px;align-items:center;min-height:74px;margin:24px 0 14px;padding:16px;font-weight:800;line-height:1.6;display:flex}.feedback.correct{color:#175b38;background:#d9f0dc}.feedback.incorrect{color:#8a3a27;background:#fde1d5}.reset-button{color:var(--forest-dark);background:#fff}.board-shell{background:#7d4d24;border-radius:26px;width:min(100%,590px);margin-inline:auto;padding:14px;box-shadow:0 8px #573319,0 20px 35px #351f0c33}.go-board{aspect-ratio:1;border-radius:16px;width:100%;display:block}.board-wood{fill:var(--wood)}.board-lines line{stroke:#61451f;stroke-width:.42px}.stone{stroke-width:.8px;filter:drop-shadow(0 1.2px 1px #00000059);pointer-events:none}.stone.black{fill:#1f2824;stroke:#090d0b}.stone.white{fill:#fffdf4;stroke:#666b66}.empty-point{fill:#0000;pointer-events:none}.hit-target{fill:#0000;stroke:#0000;cursor:pointer;pointer-events:all}.hit-target:focus{stroke:#efff65;stroke-width:1.2px;outline:none}.last-move-ring{fill:none;stroke:#efff65;stroke-width:1.1px;pointer-events:none}.move-number{pointer-events:none;font-size:4.1px;font-weight:900}.move-number.black{fill:#fffdf4}.move-number.white{fill:#202824}.coming-soon{margin:80px 0}.feature-grid{grid-template-columns:repeat(3,1fr);gap:16px;margin-top:22px;display:grid}.feature-grid article{background:#ffffffb8;border:1px solid #28735a2e;border-radius:24px;min-height:150px;padding:24px}.feature-grid strong{color:var(--forest-dark);font-size:1.3rem}.feature-grid p{color:var(--muted);line-height:1.7}footer{color:var(--muted);border-top:1px solid #2531281f;justify-content:space-between;gap:20px;padding:30px 4px 42px;display:flex}@media (max-width:760px){main{width:min(100% - 20px,620px)}.site-header{align-items:flex-start;padding:18px 2px}.brand{padding-top:8px}.brand img{width:142px}.auth-wrap small{display:none}.auth-controls button{min-height:44px;padding:8px 12px;font-size:.8rem}.hero{border-radius:28px;grid-template-columns:1fr;min-height:470px;padding:34px 24px}.hero h1{font-size:clamp(2.2rem,11vw,3.3rem)}.hero-logo{width:min(100%,360px);margin-top:-14px}.hero-motif{height:120px}.hero-motif span{width:90px;height:90px;font-size:4.4rem}.hero-motif span:first-child{left:18%}.hero-motif span:nth-child(2){right:18%}.section-heading{margin-top:52px;display:block}.catalog-controls{flex-direction:column;align-items:stretch}.problem-list{justify-content:stretch}.problem-list button{flex:1}.problem-card{border-radius:26px;grid-template-columns:1fr;padding:22px 16px 28px}.board-shell{border-radius:19px;order:-1;padding:9px}.feedback{min-height:62px}.feature-grid{grid-template-columns:1fr}footer{flex-direction:column}}