/* ==========================================================================
   SciChain Documentation — styles.css
   Self-contained, no external dependencies. Light + dark theming.
   Aesthetic: quantum-secure infrastructure. Lattice motif, violet accent.
   ========================================================================== */

:root {
  /* Brand palette */
  --violet-500: #7c5cff;
  --violet-400: #9878ff;
  --violet-300: #b9a4ff;
  --cyan-400:   #22d3ee;
  --cyan-300:   #67e8f9;

  /* Light theme (default) */
  --bg:          #f7f6fb;
  --bg-alt:      #ffffff;
  --surface:     #ffffff;
  --surface-2:   #f1eefb;
  --border:      #e4e1f0;
  --border-strong: #cfc9e6;
  --text:        #1a1730;
  --text-muted:  #565273;
  --text-faint:  #8b87a3;
  --accent:      #6b46e0;
  --accent-soft: #efeaff;
  --accent-cyan: #0891b2;
  --code-bg:     #f4f2fb;
  --code-text:   #322c55;
  --hero-grid:   rgba(107, 70, 224, 0.10);
  --hero-glow:   rgba(124, 92, 255, 0.16);
  --shadow:      0 1px 2px rgba(26,23,48,.06), 0 8px 24px rgba(26,23,48,.06);
  --shadow-lg:   0 12px 48px rgba(70,40,150,.14);

  --sidebar-w: 268px;
  --topbar-h: 60px;
  --content-max: 820px;

  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-display: "Space Grotesk", "SF Pro Display", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", "Cascadia Code", ui-monospace, "Menlo", Consolas, monospace;
}

:root[data-theme="dark"] {
  --bg:          #0b0b16;
  --bg-alt:      #0f0f1e;
  --surface:     #14142399;
  --surface-2:   #191830;
  --border:      #262441;
  --border-strong: #35325c;
  --text:        #eceafb;
  --text-muted:  #a9a5cc;
  --text-faint:  #726e94;
  --accent:      #a78bfa;
  --accent-soft: #1e1a3d;
  --accent-cyan: #22d3ee;
  --code-bg:     #12111f;
  --code-text:   #d6d2f0;
  --hero-grid:   rgba(167, 139, 250, 0.09);
  --hero-glow:   rgba(124, 92, 255, 0.22);
  --shadow:      0 1px 2px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.35);
  --shadow-lg:   0 16px 60px rgba(0,0,0,.5);
}

/* Auto dark for users without an explicit toggle preference */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:          #0b0b16;
    --bg-alt:      #0f0f1e;
    --surface:     #14142399;
    --surface-2:   #191830;
    --border:      #262441;
    --border-strong: #35325c;
    --text:        #eceafb;
    --text-muted:  #a9a5cc;
    --text-faint:  #726e94;
    --accent:      #a78bfa;
    --accent-soft: #1e1a3d;
    --accent-cyan: #22d3ee;
    --code-bg:     #12111f;
    --code-text:   #d6d2f0;
    --hero-grid:   rgba(167, 139, 250, 0.09);
    --hero-glow:   rgba(124, 92, 255, 0.22);
    --shadow:      0 1px 2px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.35);
    --shadow-lg:   0 16px 60px rgba(0,0,0,.5);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--topbar-h) + 16px); }

body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

::selection { background: var(--violet-500); color: #fff; }

/* ---------------------------------------------------------------- Top bar */
.topbar {
  position: fixed; top: 0; left: 0; right: 0; height: var(--topbar-h);
  display: flex; align-items: center; gap: 16px;
  padding: 0 20px;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

.brand {
  display: flex; align-items: center; gap: 11px;
  font-family: var(--font-display);
  font-weight: 700; font-size: 1.16rem; letter-spacing: -0.02em;
  color: var(--text);
}
.brand:hover { text-decoration: none; }
.brand .logo {
  width: 30px; height: 30px; flex: none;
  display: grid; place-items: center;
}
.brand .logo svg { width: 30px; height: 30px; display: block; }
.brand .sci { color: var(--text); }
.brand .chain {
  background: linear-gradient(92deg, var(--violet-500), var(--cyan-400));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.brand .tag {
  font-family: var(--font-mono); font-size: .62rem; font-weight: 600;
  letter-spacing: .08em; text-transform: uppercase;
  color: var(--accent); background: var(--accent-soft);
  padding: 2px 7px; border-radius: 999px; margin-left: 2px;
}

.topbar-spacer { flex: 1; }

.topbar nav.toplinks { display: flex; gap: 22px; align-items: center; }
.topbar nav.toplinks a {
  color: var(--text-muted); font-size: .9rem; font-weight: 500;
}
.topbar nav.toplinks a:hover { color: var(--text); text-decoration: none; }

.icon-btn {
  width: 38px; height: 38px; border-radius: 9px; border: 1px solid var(--border);
  background: var(--surface); color: var(--text-muted);
  display: grid; place-items: center; cursor: pointer; flex: none;
  transition: border-color .15s, color .15s;
}
.icon-btn:hover { color: var(--text); border-color: var(--border-strong); }
.icon-btn svg { width: 18px; height: 18px; }

.theme-toggle .moon { display: none; }
:root[data-theme="dark"] .theme-toggle .sun { display: none; }
:root[data-theme="dark"] .theme-toggle .moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .sun { display: none; }
  :root:not([data-theme="light"]) .theme-toggle .moon { display: block; }
}

.menu-btn { display: none; }

/* --------------------------------------------------------------- Layout */
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  max-width: 1440px; margin: 0 auto;
}

/* --------------------------------------------------------------- Sidebar */
.sidebar {
  position: sticky; top: var(--topbar-h);
  height: calc(100vh - var(--topbar-h));
  overflow-y: auto;
  padding: 26px 14px 60px 22px;
  border-right: 1px solid var(--border);
}
.sidebar::-webkit-scrollbar { width: 8px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 8px; }

.nav-group + .nav-group { margin-top: 24px; }
.nav-group-title {
  font-family: var(--font-mono); font-size: .68rem; font-weight: 600;
  letter-spacing: .12em; text-transform: uppercase; color: var(--text-faint);
  padding: 0 12px; margin: 0 0 8px;
}
.sidebar ul { list-style: none; margin: 0; padding: 0; }
.sidebar li a {
  display: block; padding: 7px 12px; margin: 1px 0;
  border-radius: 8px; color: var(--text-muted);
  font-size: .905rem; font-weight: 500;
  border-left: 2px solid transparent;
  transition: background .13s, color .13s;
}
.sidebar li a:hover { background: var(--surface-2); color: var(--text); text-decoration: none; }
.sidebar li a.active {
  background: var(--accent-soft); color: var(--accent);
  font-weight: 600;
}

/* --------------------------------------------------------------- Content */
.main { min-width: 0; padding-top: var(--topbar-h); }
.content {
  max-width: var(--content-max);
  padding: 46px 40px 120px;
  margin: 0 auto;
}
.content.wide { max-width: 1100px; }

.breadcrumb {
  font-family: var(--font-mono); font-size: .74rem; letter-spacing: .04em;
  color: var(--text-faint); margin-bottom: 18px; text-transform: uppercase;
}
.breadcrumb span { color: var(--accent); }

.content h1 {
  font-family: var(--font-display);
  font-size: 2.5rem; line-height: 1.08; letter-spacing: -0.035em;
  font-weight: 700; margin: 0 0 .5em;
}
.content h2 {
  font-family: var(--font-display);
  font-size: 1.55rem; letter-spacing: -0.02em; font-weight: 650;
  margin: 2.4em 0 .7em; padding-top: .3em;
  scroll-margin-top: 80px;
}
.content h3 {
  font-size: 1.16rem; font-weight: 650; letter-spacing: -0.01em;
  margin: 1.9em 0 .5em; scroll-margin-top: 80px;
}
.content h2 + h3 { margin-top: 1em; }
.lead {
  font-size: 1.2rem; line-height: 1.55; color: var(--text-muted);
  margin: 0 0 1.6em; max-width: 46em;
}
.content p { margin: 0 0 1.1em; }
.content ul, .content ol { margin: 0 0 1.2em; padding-left: 1.3em; }
.content li { margin: .35em 0; }
.content strong { color: var(--text); font-weight: 650; }

hr.rule {
  border: none; height: 1px; margin: 3em 0;
  background: linear-gradient(90deg, var(--border-strong), transparent);
}

/* --------------------------------------------------- Inline & block code */
code {
  font-family: var(--font-mono); font-size: .86em;
  background: var(--code-bg); color: var(--code-text);
  padding: .12em .4em; border-radius: 5px;
  border: 1px solid var(--border);
}
pre {
  position: relative;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px 18px;
  overflow-x: auto;
  margin: 0 0 1.4em;
  font-size: .855rem; line-height: 1.6;
  box-shadow: var(--shadow);
}
pre code {
  background: none; border: none; padding: 0; font-size: inherit;
  color: var(--code-text); display: block; white-space: pre;
}
.codewrap { position: relative; }
.copy-btn {
  position: absolute; top: 9px; right: 9px;
  font-family: var(--font-mono); font-size: .68rem; font-weight: 600;
  letter-spacing: .05em; text-transform: uppercase;
  padding: 5px 9px; border-radius: 7px; cursor: pointer;
  background: var(--surface-2); color: var(--text-muted);
  border: 1px solid var(--border); opacity: 0;
  transition: opacity .15s, color .15s, border-color .15s;
  z-index: 2;
}
.codewrap:hover .copy-btn { opacity: 1; }
.copy-btn:hover { color: var(--accent); border-color: var(--accent); }
.copy-btn.copied { color: var(--accent-cyan); border-color: var(--accent-cyan); }

/* token coloring (applied via spans in HTML) */
.tok-kw { color: #b57cff; }
.tok-str { color: #4fb884; }
.tok-num { color: #cf7ee0; }
.tok-com { color: var(--text-faint); font-style: italic; }
.tok-fn  { color: #4aa3e0; }
.tok-attr{ color: #d98a4e; }
:root[data-theme="dark"] .tok-str { color: #7fe0a8; }
:root[data-theme="dark"] .tok-fn { color: #6fc3ff; }
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]) .tok-str { color: #7fe0a8; }
  :root:not([data-theme="light"]) .tok-fn { color: #6fc3ff; }
}

/* --------------------------------------------------------------- Tables */
.table-wrap { overflow-x: auto; margin: 0 0 1.6em; border-radius: 12px; border: 1px solid var(--border); box-shadow: var(--shadow); }
table { border-collapse: collapse; width: 100%; font-size: .9rem; }
thead th {
  text-align: left; font-family: var(--font-mono);
  font-size: .72rem; letter-spacing: .06em; text-transform: uppercase;
  color: var(--text-muted); font-weight: 600;
  padding: 12px 16px; background: var(--surface-2);
  border-bottom: 1px solid var(--border);
}
tbody td { padding: 11px 16px; border-bottom: 1px solid var(--border); vertical-align: top; }
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover { background: color-mix(in srgb, var(--accent-soft) 45%, transparent); }
table code { font-size: .8rem; }

/* --------------------------------------------------------------- Callouts */
.callout {
  display: flex; gap: 13px; align-items: flex-start;
  padding: 15px 17px; border-radius: 12px; margin: 0 0 1.4em;
  border: 1px solid var(--border); background: var(--surface-2);
  font-size: .94rem;
}
.callout .ic { flex: none; width: 20px; height: 20px; margin-top: 1px; }
.callout p:last-child { margin-bottom: 0; }
.callout.note { border-left: 3px solid var(--accent); }
.callout.warn { border-left: 3px solid #e0a030; background: color-mix(in srgb, #e0a030 8%, var(--surface-2)); }
.callout.tip  { border-left: 3px solid var(--accent-cyan); }
.callout-title { font-weight: 650; color: var(--text); display: block; margin-bottom: 2px; }

/* --------------------------------------------------------------- Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-weight: 600; font-size: .94rem;
  padding: 11px 20px; border-radius: 10px;
  border: 1px solid transparent; cursor: pointer; transition: transform .12s, box-shadow .15s, background .15s;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary {
  background: linear-gradient(96deg, var(--violet-500), #6a4bf0);
  color: #fff; box-shadow: 0 6px 20px rgba(124,92,255,.32);
}
.btn-primary:hover { box-shadow: 0 10px 28px rgba(124,92,255,.42); }
.btn-ghost {
  background: var(--surface); color: var(--text);
  border-color: var(--border-strong);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

/* --------------------------------------------------------------- Hero */
.hero {
  position: relative; overflow: hidden;
  border-bottom: 1px solid var(--border);
  padding: 74px 40px 66px;
}
.hero-inner { max-width: 1100px; margin: 0 auto; position: relative; z-index: 2; }
#lattice {
  position: absolute; inset: 0; width: 100%; height: 100%;
  z-index: 1; opacity: .9;
}
.hero::after {
  content: ""; position: absolute; z-index: 0; inset: 0;
  background:
    radial-gradient(680px 380px at 78% -8%, var(--hero-glow), transparent 62%),
    linear-gradient(0deg, var(--hero-grid) 1px, transparent 1px) 0 0 / 100% 34px,
    linear-gradient(90deg, var(--hero-grid) 1px, transparent 1px) 0 0 / 34px 100%;
  -webkit-mask-image: linear-gradient(180deg, #000 60%, transparent);
  mask-image: linear-gradient(180deg, #000 60%, transparent);
}
.hero-eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-mono); font-size: .74rem; font-weight: 600;
  letter-spacing: .06em; text-transform: uppercase; color: var(--accent);
  background: var(--accent-soft); border: 1px solid var(--border);
  padding: 6px 13px; border-radius: 999px; margin-bottom: 22px;
}
.hero-eyebrow .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--cyan-400); box-shadow: 0 0 8px var(--cyan-400); }
.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 5.6vw, 4rem); line-height: 1.03;
  letter-spacing: -0.04em; font-weight: 700; margin: 0 0 .35em; max-width: 15ch;
}
.hero h1 .grad {
  background: linear-gradient(96deg, var(--violet-400), var(--cyan-400));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero .lead { font-size: 1.24rem; max-width: 40em; color: var(--text-muted); }
.hero-actions { display: flex; gap: 13px; flex-wrap: wrap; margin-top: 28px; }

/* chain params ticker card (hero signature) */
.params-card {
  margin-top: 40px; display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--border-strong); border-radius: 14px;
  overflow: hidden; background: var(--surface); backdrop-filter: blur(8px);
  box-shadow: var(--shadow-lg); max-width: 760px;
}
.params-card .cell { padding: 16px 18px; border-right: 1px solid var(--border); }
.params-card .cell:last-child { border-right: none; }
.params-card .k {
  font-family: var(--font-mono); font-size: .66rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--text-faint); margin-bottom: 5px;
}
.params-card .v {
  font-family: var(--font-mono); font-size: 1.12rem; font-weight: 600; color: var(--text);
  display: flex; align-items: baseline; gap: 5px;
}
.params-card .v small { font-size: .7rem; color: var(--text-faint); font-weight: 500; }
.live-dot { width: 8px; height: 8px; border-radius: 50%; background: #2fce8f; box-shadow: 0 0 8px #2fce8f; display: inline-block; animation: pulse 1.8s infinite; }
@keyframes pulse { 0%,100%{opacity:1} 50%{opacity:.35} }

/* --------------------------------------------------------------- Feature grid */
.section { max-width: 1100px; margin: 0 auto; padding: 60px 40px; }
.section-head { margin-bottom: 34px; }
.section-head .eyebrow {
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--accent); font-weight: 600;
}
.section-head h2 {
  font-family: var(--font-display); font-size: 2rem; letter-spacing: -0.03em;
  font-weight: 700; margin: .3em 0 .2em;
}
.section-head p { color: var(--text-muted); max-width: 52em; font-size: 1.05rem; margin: 0; }

.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.feature {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 15px; padding: 24px 22px;
  transition: transform .16s, border-color .16s, box-shadow .16s;
  position: relative; overflow: hidden;
}
.feature:hover { transform: translateY(-3px); border-color: var(--border-strong); box-shadow: var(--shadow-lg); }
.feature .fic {
  width: 42px; height: 42px; border-radius: 11px; display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent); margin-bottom: 16px;
}
.feature .fic svg { width: 22px; height: 22px; }
.feature h3 { margin: 0 0 8px; font-size: 1.1rem; font-weight: 650; letter-spacing: -0.01em; }
.feature p { margin: 0; color: var(--text-muted); font-size: .93rem; line-height: 1.55; }

/* quicklinks */
.quicklinks { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.qlink {
  display: flex; gap: 15px; align-items: flex-start;
  padding: 20px 22px; border-radius: 14px;
  border: 1px solid var(--border); background: var(--surface);
  transition: border-color .15s, transform .15s;
}
.qlink:hover { border-color: var(--accent); transform: translateY(-2px); text-decoration: none; }
.qlink .num { font-family: var(--font-mono); font-size: .8rem; color: var(--accent); font-weight: 600; padding-top: 2px; }
.qlink h4 { margin: 0 0 4px; font-size: 1.02rem; color: var(--text); font-weight: 650; }
.qlink p { margin: 0; font-size: .88rem; color: var(--text-muted); }

/* strip band */
.band {
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
  background:
    radial-gradient(600px 200px at 20% 0%, var(--hero-glow), transparent 70%),
    var(--bg-alt);
}
.band-inner { max-width: 1100px; margin: 0 auto; padding: 54px 40px; text-align: center; }
.band-inner h2 { font-family: var(--font-display); font-size: 1.9rem; letter-spacing: -0.03em; margin: 0 0 .4em; }
.band-inner p { color: var(--text-muted); max-width: 40em; margin: 0 auto 1.4em; font-size: 1.05rem; }

/* --------------------------------------------------------------- On-page TOC / next-prev */
.page-nav {
  display: flex; justify-content: space-between; gap: 16px;
  margin-top: 56px; padding-top: 28px; border-top: 1px solid var(--border);
}
.page-nav a {
  flex: 1; padding: 16px 18px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--surface); transition: border-color .15s;
}
.page-nav a:hover { border-color: var(--accent); text-decoration: none; }
.page-nav a.next { text-align: right; }
.page-nav .dir { font-family: var(--font-mono); font-size: .7rem; letter-spacing: .08em; text-transform: uppercase; color: var(--text-faint); }
.page-nav .ttl { font-weight: 650; color: var(--text); }

/* --------------------------------------------------------------- Footer */
.footer {
  border-top: 1px solid var(--border); background: var(--bg-alt);
}
.footer-inner {
  max-width: 1100px; margin: 0 auto; padding: 44px 40px;
  display: flex; justify-content: space-between; gap: 30px; flex-wrap: wrap;
  font-size: .9rem; color: var(--text-muted);
}
.footer .brand { font-size: 1rem; margin-bottom: 10px; }
.footer a { color: var(--text-muted); }
.footer a:hover { color: var(--accent); }
.footer-cols { display: flex; gap: 54px; flex-wrap: wrap; }
.footer-col h5 { font-family: var(--font-mono); font-size: .68rem; letter-spacing: .1em; text-transform: uppercase; color: var(--text-faint); margin: 0 0 10px; }
.footer-col ul { list-style: none; margin: 0; padding: 0; }
.footer-col li { margin: 5px 0; }

/* --------------------------------------------------------------- Misc */
.pill {
  font-family: var(--font-mono); font-size: .72rem; font-weight: 600;
  padding: 2px 9px; border-radius: 999px; letter-spacing: .02em;
  background: var(--accent-soft); color: var(--accent); border: 1px solid var(--border);
  white-space: nowrap;
}
.pill.cyan { color: var(--accent-cyan); background: color-mix(in srgb, var(--accent-cyan) 12%, transparent); }
.pill.gray { color: var(--text-muted); background: var(--surface-2); }

.anchor-link { color: var(--text-faint); margin-left: .4em; opacity: 0; font-weight: 400; }
h2:hover .anchor-link, h3:hover .anchor-link { opacity: 1; }

.kbd {
  font-family: var(--font-mono); font-size: .78rem;
  background: var(--surface-2); border: 1px solid var(--border-strong);
  border-bottom-width: 2px; border-radius: 6px; padding: 1px 6px;
}

.mono-inline { font-family: var(--font-mono); font-size: .9em; }

.scrim {
  display: none; position: fixed; inset: 0; z-index: 90;
  background: rgba(8,8,18,.55); backdrop-filter: blur(2px);
}

/* --------------------------------------------------------------- Responsive */
@media (max-width: 1024px) {
  :root { --sidebar-w: 240px; }
  .content { padding: 40px 28px 100px; }
}

@media (max-width: 860px) {
  .layout { grid-template-columns: 1fr; }
  .menu-btn { display: grid; }
  .topbar nav.toplinks { display: none; }
  .sidebar {
    position: fixed; top: var(--topbar-h); bottom: 0; left: 0;
    width: 300px; background: var(--bg-alt); z-index: 95;
    transform: translateX(-100%); transition: transform .22s ease;
    box-shadow: var(--shadow-lg); height: auto;
  }
  .sidebar.open { transform: translateX(0); }
  .scrim.show { display: block; }
  .feature-grid, .quicklinks { grid-template-columns: 1fr; }
  .params-card { grid-template-columns: repeat(2, 1fr); }
  .params-card .cell:nth-child(2) { border-right: none; }
  .hero { padding: 54px 26px 48px; }
  .section, .band-inner, .footer-inner { padding-left: 26px; padding-right: 26px; }
  .content h1 { font-size: 2rem; }
  .page-nav { flex-direction: column; }
}

@media (max-width: 480px) {
  .params-card { grid-template-columns: 1fr; }
  .params-card .cell { border-right: none; }
  .brand .tag { display: none; }
}

/* --------------------------------------------------------------- Motion */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; scroll-behavior: auto !important; transition: none !important; }
  html { scroll-behavior: auto; }
}

/* Focus visibility */
a:focus-visible, button:focus-visible, .btn:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 6px;
}