:root{--color-brand:#d62828;--color-brand-strong:#9c1b1b;--color-bg:#fafafa;--color-surface:#fff;--color-surface-muted:#f3f3f3;--color-text:#1a1a1a;--color-text-muted:#555;--color-text-subtle:#888;--color-border:#e5e5e5;--color-border-strong:#cfcfcf;--color-success:#1f7a3b;--color-warning:#b8860b;--color-error:#c0252b;--color-info:#0b66a5;--layout-max-width:960px;--layout-padding-x:16px;--space-1:4px;--space-2:8px;--space-3:12px;--space-4:16px;--space-5:24px;--space-6:32px;--space-7:48px;--font-size-base:16px;--font-size-sm:14px;--font-size-lg:18px;--font-size-xl:22px;--font-size-2xl:28px;--line-height-base:1.6}@media (prefers-color-scheme:dark){:root{--color-bg:#121212;--color-surface:#1c1c1c;--color-surface-muted:#242424;--color-text:#f5f5f5;--color-text-muted:#b8b8b8;--color-text-subtle:#888;--color-border:#2e2e2e;--color-border-strong:#3a3a3a}}*,:before,:after{box-sizing:border-box}html,body{margin:0;padding:0}body{background:var(--color-bg);color:var(--color-text);font-family:Noto Sans JP,-apple-system,BlinkMacSystemFont,Hiragino Sans,Yu Gothic UI,Meiryo,sans-serif;font-size:var(--font-size-base);line-height:var(--line-height-base);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}a{color:inherit;text-underline-offset:3px}button{font-family:inherit;font-size:inherit;cursor:pointer}button:disabled{cursor:not-allowed}.page{padding-top:var(--space-3)}.page-header{margin-bottom:var(--space-5)}.page-header h1{font-size:var(--font-size-2xl);margin:0 0 var(--space-2) 0;color:var(--color-text);letter-spacing:.01em}.page-header p{color:var(--color-text-muted);max-width:44em;margin:0}.sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.card-shell{background:var(--color-surface);border:1px solid var(--color-border);padding:var(--space-5);margin-top:var(--space-4);border-radius:6px}@media (min-width:600px){.card-shell{padding:var(--space-6)}}:focus-visible{outline:2px solid var(--color-brand);outline-offset:2px}