:root{--ssf-surface:#ffffff;--ssf-ink:#2c3e50;--ssf-line:#d9e0e6;--ssf-night:#1c2430;--ssf-on-night:#eef2f5;--ssf-night-link:#c9d2dd;--ssf-signalstuff:#3bb54a;--ssf-hamstudy:#00bcd6;--ssf-examtools:#c79100;--ssf-hambook:#d60000}@media(prefers-color-scheme:dark){:root{--ssf-surface:#1a212a;--ssf-ink:#eef2f5;--ssf-line:#2e3946}}.ssf-header{display:flex;align-items:center;gap:32px;height:80px;box-sizing:border-box;padding-left:max(32px,env(safe-area-inset-left,0px));padding-right:max(32px,env(safe-area-inset-right,0px));background:var(--ssf-surface);border-bottom:1px solid var(--ssf-line);font-family:inherit}.ssf-header__home{display:block;flex:none}.ssf-header__logo{height:48px;width:auto;display:block}.ssf-header__logo--dark{display:none}@media(prefers-color-scheme:dark){.ssf-header__logo--light{display:none}.ssf-header__logo--dark{display:block}}.ssf-header nav{display:flex;gap:24px;flex:1;align-self:stretch;min-width:0}.ssf-header nav a{display:flex;align-items:center;font-size:15px;line-height:20px;font-weight:600;color:var(--ssf-ink);text-decoration:none;white-space:nowrap}.ssf-header nav a:hover,.ssf-header nav a[aria-current=page]{text-decoration:underline 3px var(--ssf-line);text-underline-offset:8px;text-decoration-skip-ink:none}.ssf-header nav a[aria-current=page]{text-decoration-color:var(--ssf-hambook)}.ssf-header__btn{display:none;flex:none;cursor:pointer;padding:6px;margin:-6px;line-height:0}.ssf-header__btn img{width:24px;height:24px;display:block}@media(prefers-color-scheme:dark){.ssf-header__btn img{filter:invert(1)}}#menu-control:focus-visible~.ssf-header label[for=menu-control],#toc-control:focus-visible~.ssf-header label[for=toc-control]{outline:2px solid var(--ssf-hamstudy);border-radius:4px}@media(max-width:896px){.ssf-header{height:64px}.ssf-header__logo{height:40px}}@media(max-width:560px){.ssf-header{gap:16px;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}.ssf-header nav{gap:14px}.ssf-header nav a{font-size:14px}}.ssf-footer{background:var(--ssf-night);color:var(--ssf-on-night);font-family:inherit}.ssf-stripe{display:grid;grid-template-columns:repeat(4,1fr);height:6px}.ssf-stripe span:nth-child(1){background:var(--ssf-hambook)}.ssf-stripe span:nth-child(2){background:var(--ssf-hamstudy)}.ssf-stripe span:nth-child(3){background:var(--ssf-examtools)}.ssf-stripe span:nth-child(4){background:var(--ssf-signalstuff)}.ssf-footer__inner{display:flex;flex-wrap:wrap;gap:40px;justify-content:space-between;max-width:1216px;margin:0 auto;box-sizing:border-box;padding-block:40px 32px;padding-left:max(32px,env(safe-area-inset-left,0px));padding-right:max(32px,env(safe-area-inset-right,0px))}.ssf-footer h4{margin:0 0 10px;font-size:13px;line-height:16px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;opacity:.85;color:inherit}.ssf-footer ul{list-style:none;margin:0;padding:0;display:grid;gap:6px}.ssf-footer li{margin:0;line-height:20px}.ssf-footer a,.ssf-footer a:visited{color:var(--ssf-night-link);text-decoration:none;font-size:14px;line-height:20px}.ssf-footer a:hover{color:var(--ssf-on-night)}.ssf-family a::before{content:"";display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:8px;background:var(--dot)}.ssf-family a[aria-current=page]{font-weight:700}.ssf-family [data-p=signalstuff]{--dot:var(--ssf-signalstuff)}.ssf-family [data-p=hamstudy]{--dot:var(--ssf-hamstudy)}.ssf-family [data-p=examtools]{--dot:var(--ssf-examtools)}.ssf-family [data-p=hambook]{--dot:var(--ssf-hambook)}.ssf-footer__base{border-top:1px solid rgba(238,242,245,.15);padding-block:14px;text-align:center;font-size:13px;line-height:20px;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}@media screen and (min-width:56.0625rem){.ssf-chrome .book-menu .book-menu-content,.ssf-chrome .book-toc .book-toc-content{position:sticky;top:0;bottom:auto;max-height:100vh}.ssf-chrome .ssf-header{padding-left:max(16px,calc(50% - 39rem),env(safe-area-inset-left,0px));padding-right:max(16px,calc(50% - 39rem),env(safe-area-inset-right,0px))}}@media screen and (max-width:56rem){.ssf-chrome .ssf-header__btn{display:block}.ssf-chrome .book-header>.flex{display:none}.ssf-chrome .ssf-header{gap:14px}.ssf-chrome .ssf-header nav{gap:14px}}@media screen and (max-width:26rem){.ssf-chrome .ssf-header nav a{font-size:13px}.ssf-chrome .ssf-header nav{gap:10px}.ssf-chrome .ssf-header__logo{height:28px}}.ssf-drawer-close{display:none}@media screen and (max-width:56rem){.ssf-chrome .ssf-drawer-close{display:flex;align-items:center;gap:10px;height:80px;box-sizing:border-box;margin:-1rem -1rem 1rem;padding:0 1rem;border-bottom:1px solid var(--ssf-line);font-size:15px;font-weight:600;color:var(--ssf-ink);cursor:pointer}.ssf-chrome .ssf-drawer-close svg{flex:none}@media(max-width:896px){.ssf-chrome .ssf-drawer-close{height:64px}}#menu-control:focus~main label.ssf-drawer-close[for=menu-control]{outline:none}#menu-control:focus-visible~main label.ssf-drawer-close[for=menu-control]{outline:2px solid var(--ssf-hamstudy);outline-offset:-4px}}@media print{.ssf-header,.ssf-footer{display:none !important}}