/* Pyford Notes - Python Programming Blog */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --pyk-bg:      #1a1f2e;
  --pyk-bg2:     #141925;
  --pyk-bg3:     #0d1117;
  --pyk-surface: #21293d;
  --pyk-border:  #2d3852;
  --pyk-border2: #3d4e6a;
  --pyk-text:    #c5d0e4;
  --pyk-text2:   #7e92b0;
  --pyk-head:    #e8eef8;
  --pyk-teal:    #3ecf8e;
  --pyk-teal2:   #2aad72;
  --pyk-cyan:    #5bcfe0;
  --pyk-yellow:  #e2b845;
  --pyk-pink:    #e07b8a;
  --pyk-purple:  #a78bfa;
  --pyk-wrap:    1180px;
  --pyk-side:    240px;
  --pyk-r:       5px;
}

html { font-size: 16px; scroll-behavior: smooth; }
body {
  background: var(--pyk-bg);
  color: var(--pyk-text);
  font-family: 'Segoe UI', system-ui, -apple-system, Arial, sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--pyk-teal); text-decoration: none; }
a:hover { color: var(--pyk-cyan); text-decoration: underline; }
img { max-width: 100%; display: block; }

code, kbd, samp {
  font-family: 'Fira Code', 'Cascadia Code', Consolas, 'Liberation Mono', monospace;
  font-size: 0.88em;
  background: var(--pyk-bg3);
  border: 1px solid var(--pyk-border);
  border-radius: 3px;
  padding: 1px 5px;
  color: var(--pyk-cyan);
}
pre {
  font-family: 'Fira Code', 'Cascadia Code', Consolas, 'Liberation Mono', monospace;
  background: var(--pyk-bg3);
  border: 1px solid var(--pyk-border);
  border-radius: var(--pyk-r);
  padding: 18px 22px;
  overflow-x: auto;
  font-size: 0.875rem;
  line-height: 1.65;
  color: #b9c9e2;
  margin: 22px 0;
}
pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
  color: inherit;
}
h1, h2, h3, h4 {
  color: var(--pyk-head);
  font-family: 'Segoe UI', system-ui, -apple-system, Arial, sans-serif;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

/* ===== Top bar ===== */
.pyk-head {
  background: var(--pyk-bg2);
  border-bottom: 1px solid var(--pyk-border);
  position: sticky;
  top: 0;
  z-index: 100;
}
.pyk-head-row {
  max-width: var(--pyk-wrap);
  margin: 0 auto;
  padding: 0 24px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.pyk-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}
.pyk-logo:hover { text-decoration: none; }
.pyk-logo-mark {
  width: 32px; height: 32px;
  background: var(--pyk-teal);
  border-radius: var(--pyk-r);
  display: flex; align-items: center; justify-content: center;
  font-family: 'Fira Code', Consolas, monospace;
  font-weight: 800; font-size: 0.9rem; color: #0d1117;
  letter-spacing: -0.04em;
  flex-shrink: 0;
}
.pyk-logo-name {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--pyk-head);
  letter-spacing: -0.01em;
}
.pyk-logo-sub {
  font-size: 0.65rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--pyk-text2);
  font-weight: 500;
}
.pyk-logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}
.pyk-nav {
  display: flex;
  gap: 4px;
  align-items: center;
  flex-wrap: wrap;
}
.pyk-nav a {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--pyk-text2);
  padding: 6px 12px;
  border-radius: 20px;
  text-decoration: none;
  transition: background 0.14s, color 0.14s;
  letter-spacing: 0.01em;
}
.pyk-nav a:hover,
.pyk-nav a[aria-current="page"] {
  background: rgba(62,207,142,0.1);
  color: var(--pyk-teal);
  text-decoration: none;
}
.pyk-nav a[aria-current="page"] {
  box-shadow: inset 0 0 0 1px var(--pyk-teal);
}

/* ===== Shell: sidebar + main ===== */
.pyk-shell {
  max-width: var(--pyk-wrap);
  margin: 0 auto;
  display: flex;
  align-items: flex-start;
  min-height: calc(100vh - 52px);
}

/* ===== Left sidebar ===== */
.pyk-sidenav {
  width: var(--pyk-side);
  flex-shrink: 0;
  background: var(--pyk-bg2);
  border-right: 1px solid var(--pyk-border);
  position: sticky;
  top: 52px;
  height: calc(100vh - 52px);
  overflow-y: auto;
  padding: 28px 0 40px;
  scrollbar-width: thin;
  scrollbar-color: var(--pyk-border2) transparent;
}
.pyk-sidenav::-webkit-scrollbar { width: 4px; }
.pyk-sidenav::-webkit-scrollbar-track { background: transparent; }
.pyk-sidenav::-webkit-scrollbar-thumb { background: var(--pyk-border2); border-radius: 2px; }

.pyk-nav-section { padding: 0 16px 20px; }
.pyk-nav-label {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--pyk-text2);
  padding: 0 4px 8px;
  display: block;
  border-bottom: 1px solid var(--pyk-border);
  margin-bottom: 8px;
}
.pyk-nav-links { list-style: none; }
.pyk-nav-links li { margin: 0; }
.pyk-nav-links a {
  display: block;
  font-size: 0.82rem;
  color: var(--pyk-text2);
  padding: 6px 8px;
  border-radius: var(--pyk-r);
  text-decoration: none;
  transition: background 0.12s, color 0.12s;
  font-family: 'Fira Code', Consolas, monospace;
  line-height: 1.3;
}
.pyk-nav-links a:hover {
  background: rgba(62,207,142,0.08);
  color: var(--pyk-teal);
  text-decoration: none;
}
.pyk-nav-links a.pyk-current {
  background: rgba(62,207,142,0.12);
  color: var(--pyk-teal);
  font-weight: 600;
}
.pyk-toc-links { list-style: none; }
.pyk-toc-links li { margin: 0; }
.pyk-toc-links a {
  display: block;
  font-size: 0.78rem;
  color: var(--pyk-text2);
  padding: 4px 8px;
  border-left: 2px solid var(--pyk-border);
  margin-left: 4px;
  text-decoration: none;
  line-height: 1.35;
  transition: border-color 0.12s, color 0.12s;
}
.pyk-toc-links a:hover {
  border-color: var(--pyk-teal);
  color: var(--pyk-teal);
  text-decoration: none;
}

/* ===== Main content area ===== */
.pyk-main {
  flex: 1;
  min-width: 0;
  padding: 40px 52px 60px;
}

/* ===== Hero on homepage ===== */
.pyk-hero {
  border-bottom: 1px solid var(--pyk-border);
  padding-bottom: 36px;
  margin-bottom: 40px;
}
.pyk-hero-eyebrow {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--pyk-teal);
  margin-bottom: 12px;
  font-family: 'Fira Code', Consolas, monospace;
}
.pyk-hero h1 {
  font-size: 2rem;
  margin-bottom: 16px;
  color: var(--pyk-head);
}
.pyk-hero-lead {
  font-size: 1.05rem;
  color: var(--pyk-text);
  max-width: 640px;
  line-height: 1.72;
  margin-bottom: 24px;
}
.pyk-hero-prompt {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--pyk-bg3);
  border: 1px solid var(--pyk-border);
  border-radius: var(--pyk-r);
  padding: 10px 18px;
  font-family: 'Fira Code', Consolas, monospace;
  font-size: 0.88rem;
  color: var(--pyk-cyan);
}
.pyk-hero-prompt .pyk-prompt-sym {
  color: var(--pyk-teal);
  font-weight: 700;
  user-select: none;
}

/* ===== Section heading ===== */
.pyk-section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--pyk-border);
}
.pyk-section-head h2 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--pyk-head);
  letter-spacing: -0.005em;
}
.pyk-section-head a {
  font-size: 0.8rem;
  color: var(--pyk-text2);
}
.pyk-section-head a:hover { color: var(--pyk-teal); }

/* ===== Entry list (homepage) ===== */
.pyk-entries { list-style: none; display: flex; flex-direction: column; gap: 1px; }
.pyk-entry {
  background: var(--pyk-surface);
  border: 1px solid var(--pyk-border);
  border-radius: var(--pyk-r);
  padding: 18px 22px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px 16px;
  transition: border-color 0.14s;
  margin-bottom: 8px;
}
.pyk-entry:hover { border-color: var(--pyk-border2); }
.pyk-entry-tag {
  grid-column: 1;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--pyk-teal);
  font-family: 'Fira Code', Consolas, monospace;
  margin-bottom: 4px;
}
.pyk-entry h3 {
  grid-column: 1;
  font-size: 0.97rem;
  font-weight: 700;
  color: var(--pyk-head);
  margin-bottom: 5px;
}
.pyk-entry h3 a { color: inherit; }
.pyk-entry h3 a:hover { color: var(--pyk-teal); text-decoration: none; }
.pyk-entry p {
  grid-column: 1;
  font-size: 0.85rem;
  color: var(--pyk-text2);
  line-height: 1.55;
}

/* ===== Article page (pyk-doc) ===== */
.pyk-doc {
  flex: 1;
  min-width: 0;
  padding: 36px 52px 60px;
  max-width: 760px;
}
.pyk-crumbs {
  font-size: 0.78rem;
  color: var(--pyk-text2);
  margin-bottom: 16px;
}
.pyk-crumbs a { color: var(--pyk-text2); }
.pyk-crumbs a:hover { color: var(--pyk-teal); text-decoration: none; }
.pyk-crumbs .pyk-sep { margin: 0 6px; }
.pyk-atag {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--pyk-bg3);
  background: var(--pyk-teal);
  padding: 3px 9px;
  border-radius: 3px;
  margin-bottom: 12px;
  font-family: 'Fira Code', Consolas, monospace;
}
.pyk-doc h1 {
  font-size: 1.8rem;
  margin-bottom: 14px;
  color: var(--pyk-head);
}
.pyk-meta {
  display: flex;
  gap: 6px;
  align-items: center;
  font-size: 0.8rem;
  color: var(--pyk-text2);
  margin-bottom: 28px;
  flex-wrap: wrap;
}
.pyk-meta-dot { color: var(--pyk-border2); }
.pyk-keybox {
  background: rgba(62,207,142,0.07);
  border: 1px solid rgba(62,207,142,0.25);
  border-left: 3px solid var(--pyk-teal);
  border-radius: var(--pyk-r);
  padding: 16px 20px;
  margin-bottom: 28px;
}
.pyk-keybox b {
  display: block;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--pyk-teal);
  margin-bottom: 8px;
  font-family: 'Fira Code', Consolas, monospace;
}
.pyk-keybox ul { list-style: none; padding: 0; }
.pyk-keybox ul li {
  font-size: 0.88rem;
  color: var(--pyk-text);
  padding: 3px 0 3px 14px;
  position: relative;
}
.pyk-keybox ul li::before {
  content: '>';
  position: absolute;
  left: 0;
  color: var(--pyk-teal);
  font-family: 'Fira Code', Consolas, monospace;
  font-weight: 700;
}
.pyk-prose { font-size: 0.95rem; }
.pyk-prose h2 {
  font-size: 1.25rem;
  margin: 32px 0 12px;
  padding-top: 20px;
  border-top: 1px solid var(--pyk-border);
  color: var(--pyk-head);
}
.pyk-prose h3 {
  font-size: 1.05rem;
  margin: 22px 0 8px;
  color: var(--pyk-head);
}
.pyk-prose p { margin-bottom: 16px; }
.pyk-prose ul, .pyk-prose ol {
  margin: 0 0 16px 22px;
}
.pyk-prose li { margin-bottom: 6px; }
.pyk-prose strong { color: var(--pyk-head); font-weight: 600; }
.pyk-prose em { color: var(--pyk-yellow); font-style: italic; }
.pyk-prose blockquote {
  border-left: 3px solid var(--pyk-purple);
  margin: 20px 0;
  padding: 10px 18px;
  background: rgba(167,139,250,0.06);
  border-radius: 0 var(--pyk-r) var(--pyk-r) 0;
  font-size: 0.92rem;
  color: var(--pyk-text);
}

/* ===== Tables ===== */
.pyk-table-wrap { overflow-x: auto; margin: 20px 0; }
.pyk-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}
.pyk-table th {
  background: var(--pyk-bg2);
  color: var(--pyk-head);
  font-weight: 700;
  text-align: left;
  padding: 10px 14px;
  border-bottom: 2px solid var(--pyk-border);
  font-family: 'Fira Code', Consolas, monospace;
  font-size: 0.82rem;
}
.pyk-table td {
  padding: 9px 14px;
  border-bottom: 1px solid var(--pyk-border);
  color: var(--pyk-text);
  vertical-align: top;
}
.pyk-table tr:last-child td { border-bottom: none; }
.pyk-table tr:nth-child(even) td { background: rgba(255,255,255,0.02); }

/* ===== Callout / note box ===== */
.pyk-note {
  background: rgba(91,207,224,0.07);
  border: 1px solid rgba(91,207,224,0.2);
  border-left: 3px solid var(--pyk-cyan);
  border-radius: var(--pyk-r);
  padding: 14px 18px;
  margin: 20px 0;
  font-size: 0.88rem;
  color: var(--pyk-text);
}
.pyk-note b {
  display: block;
  color: var(--pyk-cyan);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 6px;
  font-family: 'Fira Code', Consolas, monospace;
}
.pyk-warn {
  background: rgba(226,184,69,0.07);
  border: 1px solid rgba(226,184,69,0.2);
  border-left: 3px solid var(--pyk-yellow);
  border-radius: var(--pyk-r);
  padding: 14px 18px;
  margin: 20px 0;
  font-size: 0.88rem;
  color: var(--pyk-text);
}
.pyk-warn b {
  display: block;
  color: var(--pyk-yellow);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 6px;
  font-family: 'Fira Code', Consolas, monospace;
}

/* ===== FAQ ===== */
.pyk-faq { margin: 20px 0; }
.pyk-faq-q {
  font-weight: 700;
  color: var(--pyk-head);
  margin-bottom: 6px;
  font-size: 0.92rem;
}
.pyk-faq-q::before {
  content: 'Q: ';
  color: var(--pyk-teal);
  font-family: 'Fira Code', Consolas, monospace;
  font-size: 0.8rem;
}
.pyk-faq-a {
  margin-bottom: 18px;
  padding-left: 28px;
  font-size: 0.88rem;
  color: var(--pyk-text);
  border-left: 2px solid var(--pyk-border);
}

/* ===== Steps ===== */
.pyk-steps { counter-reset: step-cnt; list-style: none; margin: 16px 0 20px; }
.pyk-steps li {
  counter-increment: step-cnt;
  display: flex;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 14px;
}
.pyk-steps li::before {
  content: counter(step-cnt);
  flex-shrink: 0;
  width: 26px; height: 26px;
  background: var(--pyk-teal);
  color: var(--pyk-bg3);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.75rem;
  font-weight: 800;
  font-family: 'Fira Code', Consolas, monospace;
  margin-top: 2px;
}

/* ===== Footer ===== */
.pyk-foot {
  background: var(--pyk-bg2);
  border-top: 1px solid var(--pyk-border);
  padding: 36px 0 24px;
}
.pyk-foot-inner {
  max-width: var(--pyk-wrap);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  gap: 40px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}
.pyk-foot-brand {
  flex: 2;
  min-width: 200px;
}
.pyk-foot-brand .pyk-foot-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--pyk-head);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.pyk-foot-brand .pyk-foot-name span {
  font-family: 'Fira Code', Consolas, monospace;
  font-size: 0.72rem;
  color: var(--pyk-teal);
  background: rgba(62,207,142,0.1);
  padding: 2px 7px;
  border-radius: 3px;
  letter-spacing: 0.05em;
}
.pyk-foot-brand p {
  font-size: 0.82rem;
  color: var(--pyk-text2);
  line-height: 1.6;
  max-width: 360px;
}
.pyk-foot-col {
  flex: 1;
  min-width: 140px;
}
.pyk-foot-col h4 {
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--pyk-text2);
  margin-bottom: 10px;
  font-weight: 700;
  font-family: 'Fira Code', Consolas, monospace;
}
.pyk-foot-col a {
  display: block;
  font-size: 0.82rem;
  color: var(--pyk-text2);
  padding: 3px 0;
  text-decoration: none;
  transition: color 0.12s;
}
.pyk-foot-col a:hover { color: var(--pyk-teal); text-decoration: none; }
.pyk-foot-fine {
  max-width: var(--pyk-wrap);
  margin: 0 auto;
  padding: 16px 24px 0;
  font-size: 0.75rem;
  color: var(--pyk-text2);
  border-top: 1px solid var(--pyk-border);
  line-height: 1.6;
}

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .pyk-sidenav { display: none; }
  .pyk-main { padding: 28px 24px 48px; }
  .pyk-doc { padding: 28px 24px 48px; }
  .pyk-head-row { padding: 0 16px; }
}
@media (max-width: 580px) {
  .pyk-hero h1 { font-size: 1.5rem; }
  .pyk-doc h1 { font-size: 1.45rem; }
  .pyk-foot-inner { gap: 24px; }
}