:root{--paper:#ffffff;--ink:#16382b;--ink-deep:#0e2a1f;--ink-soft:#5a7668;--seal:#c73e2d;--seal-soft:#fbedea;--line:#dce3da}*{box-sizing:border-box}body,html{margin:0;padding:0}body{background:var(--paper);color:var(--ink);font-family:var(--font-gothic),"Hiragino Kaku Gothic ProN","Yu Gothic",sans-serif;-webkit-font-smoothing:antialiased;line-height:1.7}.auth-stage{min-height:100dvh;display:flex;flex-direction:column;align-items:center;padding:0 24px}.auth-accent{position:fixed;top:0;left:0;right:0;height:3px;background:var(--seal)}.auth-panel{width:min(360px,100%);margin:auto 0;padding:32px 0;animation:auth-rise .4s ease-out both}.auth-brand{font-family:var(--font-mincho),"Hiragino Mincho ProN",serif;font-size:1.15rem;font-weight:700;letter-spacing:.08em;text-align:center;margin-bottom:36px}.signin-eyebrow{margin:0 0 4px;font-size:.75rem;font-weight:500;letter-spacing:.24em;color:var(--ink-soft);text-align:center}.signin-app{margin:0;font-size:1.1rem;font-weight:700;letter-spacing:.01em;line-height:1.5;text-align:center;overflow-wrap:anywhere}.signin-divider{border:none;border-top:1px solid var(--line);margin:28px 0}.signin-button{width:100%;display:flex;align-items:center;justify-content:center;gap:12px;padding:13px 16px;border:none;border-radius:4px;background:var(--ink);color:#fff;font-family:inherit;font-size:.95rem;font-weight:600;letter-spacing:.04em;cursor:pointer;transition:background-color .15s ease}.signin-button:hover:enabled{background:var(--ink-deep)}.signin-button:focus-visible{outline:2px solid var(--seal);outline-offset:2px}.signin-button:disabled{opacity:.55;cursor:default}.signin-g{display:grid;place-items:center;width:26px;height:26px;border-radius:50%;background:#fff;flex:none}.signin-note{margin:14px 0 0;font-size:.76rem;color:var(--ink-soft);text-align:center}.signin-alert{margin:18px 0 0;padding:12px 14px;border-left:3px solid var(--seal);background:var(--seal-soft);color:#8f2c20;font-size:.85rem;border-radius:0 4px 4px 0}.error-message{margin:10px 0 0;font-size:.95rem;font-weight:700;line-height:1.8;text-align:center}.error-hint{margin:22px 0 0;padding-top:20px;border-top:1px solid var(--line);font-size:.8rem;color:var(--ink-soft);text-align:center}@keyframes auth-rise{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}@media (prefers-reduced-motion:reduce){.auth-panel{animation:none}}