@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=JetBrains+Mono:wght@400&display=swap');

:root {
  --canvas: #f7f7f4;
  --surface-card: #ffffff;
  --primary: #f54e00;
  --primary-active: #d04200;
  --ink: #26251e;
  --body-color: #5a5852;
  --muted: #807d72;
  --hairline: #e6e5e0;
  --hairline-soft: #efeee8;
  --hairline-strong: #cfcdc4;
  --surface-strong: #e6e5e0;
  --semantic-error: #cf2d56;
  --topbar-h: 56px;
  --sidebar-w: 240px;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Inter', system-ui, 'Helvetica Neue', Arial, sans-serif;
  background: var(--canvas);
  color: var(--body-color);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--ink); text-decoration: none; }
a:hover { color: var(--primary); }

code, pre, .mono { font-family: 'JetBrains Mono', monospace; font-size: 13px; }

img { max-width: 100%; height: auto; display: block; }

.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

#topbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--topbar-h);
  background: var(--canvas);
  border-bottom: 1px solid var(--hairline);
  display: flex;
  align-items: center;
  padding: 0 24px;
  justify-content: space-between;
  z-index: 100;
}

.topbar-logo {
  font-family: 'Inter', sans-serif;
  font-size: 18px;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.5px;
}

.topbar-logo span { color: var(--primary); }

.topbar-search {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--surface-card);
  border: 1px solid var(--hairline);
  border-radius: 8px;
  padding: 8px 14px;
  width: 280px;
}

.topbar-search input {
  border: none;
  background: transparent;
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  color: var(--ink);
  outline: none;
  width: 100%;
}

.topbar-search input::placeholder { color: var(--muted); }

.topbar-nav { display: flex; align-items: center; gap: 24px; }

.topbar-nav a {
  font-size: 14px;
  font-weight: 500;
  color: var(--body-color);
  transition: color 0.15s;
}

.topbar-nav a:hover { color: var(--ink); }

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}

.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--ink);
  border-radius: 2px;
}

#sidebar {
  position: fixed;
  top: var(--topbar-h);
  left: 0;
  bottom: 0;
  width: var(--sidebar-w);
  background: var(--canvas);
  border-right: 1px solid var(--hairline);
  overflow-y: auto;
  z-index: 90;
  padding: 24px 0;
}

.sidebar-section { margin-bottom: 8px; }

.sidebar-section-title {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.88px;
  text-transform: uppercase;
  color: var(--muted);
  padding: 8px 20px;
}

.sidebar-link {
  display: block;
  padding: 8px 20px;
  font-size: 14px;
  font-weight: 400;
  color: var(--body-color);
  transition: background 0.1s, color 0.1s;
  border-left: 2px solid transparent;
}

.sidebar-link:hover {
  background: var(--hairline-soft);
  color: var(--ink);
}

.sidebar-link.active {
  color: var(--primary);
  border-left-color: var(--primary);
  background: rgba(245,78,0,0.04);
  font-weight: 500;
}

#main {
  margin-left: var(--sidebar-w);
  padding-top: var(--topbar-h);
  min-height: 100vh;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
}

.section { padding: 80px 0; }

.section-sm { padding: 48px 0; }

h1 { font-size: 36px; font-weight: 400; color: var(--ink); line-height: 1.2; letter-spacing: -0.72px; }
h2 { font-size: 26px; font-weight: 400; color: var(--ink); line-height: 1.25; letter-spacing: -0.325px; margin-bottom: 16px; }
h3 { font-size: 22px; font-weight: 400; color: var(--ink); line-height: 1.3; letter-spacing: -0.11px; margin-bottom: 12px; }
h4 { font-size: 18px; font-weight: 600; color: var(--ink); line-height: 1.4; margin-bottom: 10px; }

p { margin-bottom: 16px; }

.label-upper {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.88px;
  text-transform: uppercase;
  color: var(--muted);
}

.card {
  background: var(--surface-card);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  padding: 24px;
  transition: border-color 0.15s;
}

.card:hover { border-color: var(--hairline-strong); }

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.card-link { display: block; }
.card-link .card { height: 100%; }

.entry-card { display: flex; flex-direction: column; gap: 10px; }

.entry-card .cat-tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.88px;
  text-transform: uppercase;
  color: var(--muted);
  background: var(--surface-strong);
  border-radius: 9999px;
  padding: 3px 10px;
}

.entry-card h3 { font-size: 16px; font-weight: 600; color: var(--ink); margin-bottom: 0; letter-spacing: 0; }
.entry-card p { font-size: 14px; color: var(--body-color); margin-bottom: 0; }

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--primary);
  color: #fff;
  font-size: 14px;
  font-weight: 500;
  padding: 0 18px;
  height: 40px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: background 0.15s;
  text-decoration: none;
}

.btn-primary:hover { background: var(--primary-active); color: #fff; }

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--surface-card);
  color: var(--ink);
  font-size: 14px;
  font-weight: 500;
  padding: 0 18px;
  height: 40px;
  border-radius: 8px;
  border: 1px solid var(--hairline-strong);
  cursor: pointer;
  transition: border-color 0.15s;
  text-decoration: none;
}

.btn-secondary:hover { border-color: var(--ink); color: var(--ink); }

.divider { border: none; border-top: 1px solid var(--hairline); margin: 32px 0; }

.breadcrumb { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--muted); margin-bottom: 32px; flex-wrap: wrap; }
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--ink); }
.breadcrumb .sep { color: var(--hairline-strong); }

.entry-layout { display: grid; grid-template-columns: 1fr 260px; gap: 48px; align-items: start; }

.toc {
  background: var(--surface-card);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  padding: 20px;
  position: sticky;
  top: calc(var(--topbar-h) + 24px);
}

.toc-title { font-size: 11px; font-weight: 600; letter-spacing: 0.88px; text-transform: uppercase; color: var(--muted); margin-bottom: 12px; }

.toc ol { list-style: none; counter-reset: toc-counter; }
.toc ol li { counter-increment: toc-counter; }
.toc ol li::before { content: counter(toc-counter) ". "; color: var(--muted); font-size: 13px; }
.toc a { font-size: 14px; color: var(--body-color); display: inline-block; padding: 4px 0; }
.toc a:hover { color: var(--primary); }

.prose h2 { margin-top: 48px; margin-bottom: 16px; }
.prose h3 { margin-top: 32px; }
.prose p { color: var(--body-color); line-height: 1.6; }
.prose ul, .prose ol { padding-left: 24px; margin-bottom: 16px; }
.prose ul li, .prose ol li { margin-bottom: 8px; color: var(--body-color); }

.code-block {
  background: var(--surface-card);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  padding: 20px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--ink);
  overflow-x: auto;
  margin: 24px 0;
  line-height: 1.6;
}

.disclaimer-box {
  background: var(--surface-card);
  border: 1px solid var(--hairline);
  border-left: 3px solid var(--hairline-strong);
  border-radius: 0 8px 8px 0;
  padding: 16px 20px;
  margin: 24px 0;
}

.disclaimer-box p { font-size: 13px; color: var(--muted); margin: 0; }

.related-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }

footer {
  background: var(--canvas);
  border-top: 1px solid var(--hairline);
  padding: 64px 0 48px;
}

.footer-grid { display: grid; grid-template-columns: repeat(3, 1fr) auto; gap: 48px; margin-bottom: 48px; }

.footer-col-title { font-size: 14px; font-weight: 600; color: var(--ink); margin-bottom: 16px; }

.footer-link { display: block; font-size: 14px; color: var(--body-color); margin-bottom: 10px; }
.footer-link:hover { color: var(--ink); }

.footer-contact { font-size: 14px; color: var(--body-color); line-height: 1.6; }
.footer-contact strong { color: var(--ink); font-weight: 500; }

.footer-disclaimer { font-size: 13px; color: var(--muted); border-top: 1px solid var(--hairline); padding-top: 24px; margin-bottom: 12px; }

.footer-copy { font-size: 13px; color: var(--muted); }

.hero { padding: 80px 0; }

.hero-label { margin-bottom: 16px; }

.hero h1 { margin-bottom: 20px; }

.hero-sub { font-size: 18px; color: var(--body-color); max-width: 560px; margin-bottom: 32px; line-height: 1.6; }

.filter-bar { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 32px; }

.filter-btn {
  font-size: 13px;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: 9999px;
  border: 1px solid var(--hairline);
  background: var(--surface-card);
  color: var(--body-color);
  cursor: pointer;
  transition: all 0.15s;
}

.filter-btn:hover, .filter-btn.active {
  background: var(--ink);
  color: var(--canvas);
  border-color: var(--ink);
}

.category-header {
  padding: 48px 0 32px;
  border-bottom: 1px solid var(--hairline);
  margin-bottom: 48px;
}

.page-header { padding: 48px 0; }

.faq-list { display: flex; flex-direction: column; gap: 1px; }

details {
  background: var(--surface-card);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  overflow: hidden;
}

details + details { margin-top: 8px; }

summary {
  padding: 18px 24px;
  font-size: 16px;
  font-weight: 500;
  color: var(--ink);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  list-style: none;
  user-select: none;
}

summary::-webkit-details-marker { display: none; }

summary::after {
  content: '+';
  font-size: 20px;
  color: var(--muted);
  flex-shrink: 0;
  transition: transform 0.2s;
}

details[open] summary::after { content: '−'; }

.faq-answer { padding: 0 24px 20px; color: var(--body-color); font-size: 15px; line-height: 1.6; }

.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; }

.form-group { margin-bottom: 20px; }

.form-label { display: block; font-size: 14px; font-weight: 500; color: var(--ink); margin-bottom: 6px; }

.form-input {
  display: block;
  width: 100%;
  background: var(--surface-card);
  border: 1px solid var(--hairline);
  border-radius: 8px;
  padding: 12px 16px;
  height: 44px;
  font-family: 'Inter', sans-serif;
  font-size: 15px;
  color: var(--ink);
  outline: none;
  transition: border-color 0.15s;
}

.form-input:focus { border-color: var(--ink); }
.form-input.error { border-color: var(--semantic-error); }

.form-error { font-size: 13px; color: var(--semantic-error); margin-top: 4px; display: none; }
.form-error.visible { display: block; }

.form-status { font-size: 15px; color: var(--ink); min-height: 24px; margin-top: 8px; }

.cookie-banner {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  background: var(--ink);
  color: var(--canvas);
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  z-index: 999;
  flex-wrap: wrap;
}

.cookie-text { font-size: 14px; color: rgba(247,247,244,0.85); flex: 1; min-width: 200px; }
.cookie-text a { color: var(--canvas); text-decoration: underline; }

.cookie-actions { display: flex; gap: 10px; flex-shrink: 0; }

.cookie-accept {
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 0 18px;
  height: 40px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s;
}

.cookie-accept:hover { background: var(--primary-active); }

.cookie-reject {
  background: transparent;
  color: var(--canvas);
  border: 1px solid rgba(247,247,244,0.3);
  border-radius: 8px;
  padding: 0 18px;
  height: 40px;
  font-size: 14px;
  cursor: pointer;
  transition: border-color 0.15s;
}

.cookie-reject:hover { border-color: var(--canvas); }

.mobile-menu-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(38,37,30,0.5);
  z-index: 85;
}

.mobile-menu-overlay.open { display: block; }

@media (max-width: 1024px) {
  .card-grid { grid-template-columns: repeat(2, 1fr); }
  .entry-layout { grid-template-columns: 1fr; }
  .toc { position: static; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; gap: 32px; }
  .related-cards { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  #sidebar {
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    z-index: 95;
  }

  #sidebar.open { transform: translateX(0); }

  #main { margin-left: 0; }

  .hamburger { display: flex; }

  .topbar-search { display: none; }

  .topbar-nav { display: none; }

  h1 { font-size: 28px; }
  h2 { font-size: 22px; }

  .card-grid { grid-template-columns: 1fr; }
  .related-cards { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .container { padding: 0 16px; }
  .section { padding: 48px 0; }
  .hero { padding: 48px 0; }
}