:root{--bg-primary:#fff;--bg-secondary:#fafafa;--bg-card:#fff;--bg-card-hover:#f8f8f8;--bg-elevated:#f5f5f5;--bg-emoji:linear-gradient(135deg,#f8f8f8,#f0f0f0);--text-primary:#111;--text-body:#333;--text-secondary:#555;--text-muted:#999;--text-subtle:#777;--text-link:#666;--border-color:#eee;--border-subtle:rgba(0,0,0,.04);--border-light:rgba(0,0,0,.06);--border-input:#d4d4d4;--divider:#ddd;--accent:#2563eb;--accent-hover:#1d4ed8;--accent-gradient:linear-gradient(135deg,#667eea,#764ba2);--shadow-sm:0 1px 3px rgba(0,0,0,.04),0 1px 2px rgba(0,0,0,.06);--shadow-md:0 2px 8px rgba(0,0,0,.1);--shadow-lg:0 8px 24px rgba(0,0,0,.1);--shadow-card:0 2px 8px rgba(0,0,0,.1);--shadow-card-hover:0 4px 16px rgba(0,0,0,.15);--glass-bg:hsla(0,0%,100%,.85);--glass-border:rgba(0,0,0,.06);--footer-bg:#1f2937;--footer-text:#fff;--hero-gradient:linear-gradient(180deg,#fff,#fafafa);--overlay-bg:rgba(0,0,0,.7);--modal-bg:#fff;--input-bg:#fff;--tag-bg:#fff;--tag-border:rgba(0,0,0,.08);--board-bg:#fff;--cell-bg:#fff;--cell-prefilled:#f5f5f5;--cell-hover:#f0f4ff;--cell-selected:#bdd0ff;--cell-highlighted:#e8eeff;--cell-same:#c5d8ff;--cell-border:#ddd;--cell-box-border:#333;--toast-bg:#333;--radius-sm:8px;--radius-md:12px;--radius-lg:16px;--space-1:4px;--space-2:8px;--space-3:12px;--space-4:16px;--space-5:24px;--space-6:32px;--font-size-sm:0.875rem;--font-size-md:1rem;--font-size-lg:1.25rem}[data-theme=dark]{--bg-primary:#0f0f0f;--bg-secondary:#141414;--bg-card:#1a1a1a;--bg-card-hover:#222;--bg-elevated:#1e1e1e;--bg-emoji:linear-gradient(135deg,#222,#1a1a1a);--text-primary:#e5e5e5;--text-body:silver;--text-secondary:#a0a0a0;--text-muted:#666;--text-subtle:#888;--text-link:#a0a0a0;--border-color:#2a2a2a;--border-subtle:hsla(0,0%,100%,.06);--border-light:hsla(0,0%,100%,.08);--border-input:#333;--divider:#333;--accent:#3b82f6;--accent-hover:#2563eb;--accent-gradient:linear-gradient(135deg,#667eea,#764ba2);--shadow-sm:0 1px 3px rgba(0,0,0,.2),0 1px 2px rgba(0,0,0,.15);--shadow-md:0 2px 8px rgba(0,0,0,.3);--shadow-lg:0 8px 24px rgba(0,0,0,.3);--shadow-card:0 2px 8px rgba(0,0,0,.3);--shadow-card-hover:0 4px 16px rgba(0,0,0,.4);--glass-bg:hsla(0,0%,8%,.85);--glass-border:hsla(0,0%,100%,.08);--footer-bg:#111;--footer-text:#ccc;--hero-gradient:linear-gradient(180deg,#0f0f0f,#141414);--overlay-bg:rgba(0,0,0,.8);--modal-bg:#1a1a1a;--input-bg:#1e1e1e;--tag-bg:#1e1e1e;--tag-border:hsla(0,0%,100%,.1);--board-bg:#1a1a1a;--cell-bg:#1a1a1a;--cell-prefilled:#222;--cell-hover:#1e2540;--cell-selected:#2a3a6a;--cell-highlighted:#1e2a4a;--cell-same:#253560;--cell-border:#333;--cell-box-border:#888;--toast-bg:#333}@media (prefers-reduced-motion:reduce){*,:after,:before{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important;scroll-behavior:auto!important}}*{box-sizing:border-box;padding:0;margin:0}body,html{max-width:100vw;overflow-x:hidden;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{color:var(--text-body);background:var(--bg-primary);line-height:1.6;transition:background .2s ease,color .2s ease}a{color:inherit;text-decoration:none}:focus-visible{outline:2px solid var(--accent);outline-offset:2px}.container{max-width:1200px;margin:0 auto;padding:0 20px}header{background:var(--bg-primary);box-shadow:var(--shadow-sm);position:-webkit-sticky;position:sticky;top:0;z-index:100}nav{display:flex;justify-content:space-between;align-items:center;padding:1rem 0}.logo{font-size:1.5rem;font-weight:700;color:var(--accent)}.nav-links{display:flex;list-style:none;gap:2rem}.nav-links a{transition:color .3s ease}.nav-links a:hover{color:var(--accent)}.hero{padding:4rem 0;text-align:center}.hero h1{font-size:3rem;margin-bottom:1rem;background:var(--accent-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.hero p{font-size:1.25rem;color:var(--text-secondary);margin-bottom:2rem}section{padding:4rem 0}.section-title{font-size:2rem;margin-bottom:2rem;text-align:center;color:var(--text-body)}.btn{display:inline-block;padding:.75rem 2rem;background:var(--accent);color:#fff;border:none;border-radius:5px;cursor:pointer;font-size:1rem;transition:background .3s ease}.btn:hover{background:var(--accent-hover)}.btn-secondary{background:transparent;border:2px solid var(--accent);color:var(--accent)}.btn-secondary:hover{background:var(--accent);color:#fff}.card{border-radius:8px;padding:2rem;box-shadow:var(--shadow-card);transition:transform .3s ease,box-shadow .3s ease}.card,.ui-card{background:var(--bg-card)}.ui-card{border:1px solid var(--border-subtle);border-radius:var(--radius-lg);box-shadow:var(--shadow-sm);padding:var(--space-5)}.ui-btn{border:none;border-radius:var(--radius-md);padding:.6rem 1rem;font-size:var(--font-size-sm);cursor:pointer;transition:transform .15s ease,opacity .15s ease}.ui-btn:hover{transform:translateY(-1px)}.ui-btn-primary{background:var(--accent);color:#fff}.ui-btn-secondary{background:var(--bg-secondary);color:var(--text-primary);border:1px solid var(--border-light)}.card:hover{transform:translateY(-5px);box-shadow:var(--shadow-card-hover)}footer{background:var(--footer-bg);color:var(--footer-text);text-align:center;padding:2rem 0;margin-top:4rem}.theme-toggle{background:none;border:none;cursor:pointer;font-size:1rem;padding:.2rem;line-height:1;transition:transform .2s}.theme-toggle:hover{transform:scale(1.15)}.login-form{display:flex;flex-direction:column;gap:.75rem;width:100%;max-width:320px;margin:0 auto}.login-form--compact{max-width:280px}.login-form__fields{display:flex;flex-direction:column;gap:.5rem}.login-form__input{padding:.6rem .75rem;border:1px solid var(--border-input);border-radius:8px;font-size:.95rem;background:var(--input-bg);color:var(--text-primary);outline:none;transition:border-color .2s}.login-form__input:focus{border-color:var(--accent)}.login-form__error{color:#e55;font-size:.8rem;text-align:center}.login-form__btn{padding:.6rem;border:none;border-radius:8px;background:var(--accent);color:#fff;font-weight:600;cursor:pointer;font-size:.95rem;transition:background .2s}.login-form__btn:hover{background:var(--accent-hover)}.login-form__btn:disabled{opacity:.5;cursor:not-allowed}.login-form__toggle{background:none;border:none;color:var(--text-muted);cursor:pointer;font-size:.8rem;text-align:center;transition:color .2s}.login-form__toggle:hover{color:var(--text-secondary)}.login-form__note{margin:0;font-size:.78rem;line-height:1.35;color:var(--text-muted);text-align:center}@media (max-width:768px){.hero h1{font-size:2rem}.nav-links{gap:1rem;font-size:.9rem}}