:root {
  --color-text: #1c2733;
  --color-muted: #5b6b7c;
  --color-bg: #f4f7fb;
  --color-surface: #ffffff;
  --color-accent: #1f5fbf;
  --color-accent-dark: #16468f;
  --color-accent-soft: #e8f0fd;
  --color-border: #e2e8f0;
  --color-footer-bg: #10233d;
  --color-footer-text: #b9c6d6;
  --max-width: 760px;
  --radius: 14px;
}

* {
  box-sizing: border-box;
}

html {
  background: var(--color-bg);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.65;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

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

a:hover {
  color: var(--color-accent-dark);
  text-decoration: underline;
}

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header */

.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.site-header .wrap {
  padding-top: 1.1rem;
  padding-bottom: 1.1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-header .logo {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-text);
}

.site-header .logo:hover {
  color: var(--color-text);
  text-decoration: none;
}

.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: 8px;
  background: var(--color-accent);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.site-header nav a {
  margin-left: 1.25rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-muted);
}

.site-header nav a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

/* Main content */

main {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem 1.5rem 3.5rem;
  width: 100%;
}

h1 {
  font-size: 1.85rem;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.article-body h2 {
  font-size: 1.35rem;
  margin-top: 2.2rem;
}

.article-body p,
.article-body li {
  color: var(--color-text);
}

.article-body ul,
.article-body ol {
  padding-left: 1.3rem;
}

.article-body li + li {
  margin-top: 0.35rem;
}

/* Hero (home) */

.hero {
  background: linear-gradient(135deg, var(--color-accent-soft), var(--color-surface));
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2rem 1.75rem;
  margin-bottom: 2rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.hero-text {
  flex: 1;
  min-width: 220px;
}

.hero h1 {
  margin-top: 0;
}

.hero p {
  color: var(--color-muted);
  margin-bottom: 0;
  max-width: 55ch;
}

.hero-art {
  flex-shrink: 0;
  width: 200px;
}

.hero-art svg {
  display: block;
  width: 100%;
  height: auto;
}

@media (max-width: 640px) {
  .hero-art {
    display: none;
  }
}

/* Filters (search + category pills) */

.filters {
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

#search-input {
  width: 100%;
  padding: 0.7rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: var(--color-surface) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%235b6b7c' stroke-width='2'%3E%3Ccircle cx='11' cy='11' r='7'/%3E%3Cpath d='M21 21l-4.3-4.3' stroke-linecap='round'/%3E%3C/svg%3E") no-repeat 0.9rem center;
  background-size: 1.1rem;
  padding-left: 2.6rem;
  font-size: 0.95rem;
  color: var(--color-text);
}

#search-input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

.filter-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.pill {
  font: inherit;
  cursor: pointer;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-muted);
  font-size: 0.82rem;
  font-weight: 600;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.pill:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.pill.active {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #fff;
}

.no-results {
  text-align: center;
  color: var(--color-muted);
  padding: 2rem 1rem;
}

/* Table of contents (auto-generated) */

.toc {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  border-radius: 0 10px 10px 0;
  padding: 1rem 1.25rem;
  margin: 1.5rem 0 2rem;
}

.toc-title {
  margin: 0 0 0.5rem;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-muted);
}

.toc ol {
  margin: 0;
  padding-left: 1.1rem;
  display: grid;
  gap: 0.3rem;
}

.toc a {
  font-size: 0.92rem;
}

/* Article list (cards) */

.article-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 1rem;
}

.article-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.article-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(16, 35, 61, 0.08);
  border-color: #c9d8ee;
}

.article-card-link {
  display: block;
  padding: 1.4rem 1.5rem;
  color: inherit;
}

.article-card-link:hover {
  text-decoration: none;
  color: inherit;
}

.article-card-link h2 {
  margin: 0.6rem 0 0.4rem;
  font-size: 1.1rem;
  color: var(--color-text);
}

.article-card-link p {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.95rem;
}

/* Icon bubbles */

.icon-bubble {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 12px;
  background: var(--color-accent-soft);
  color: var(--color-accent);
  margin-bottom: 0.6rem;
}

.icon-bubble-lg {
  width: 3.2rem;
  height: 3.2rem;
  border-radius: 14px;
  margin-bottom: 0.75rem;
}

.icon-bubble .icon {
  width: 60%;
  height: 60%;
}

/* Badges */

.badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  background: var(--color-accent-soft);
  color: var(--color-accent-dark);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* Article page extras */

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--color-muted);
  margin-bottom: 1.25rem;
}

.breadcrumbs .sep {
  color: var(--color-border);
}

.article-date {
  color: var(--color-muted);
  font-size: 0.9rem;
  margin-top: 0.25rem;
}

.disclaimer {
  margin-top: 2.75rem;
  padding: 1rem 1.15rem;
  background: var(--color-accent-soft);
  border-left: 3px solid var(--color-accent);
  border-radius: 0 8px 8px 0;
  font-size: 0.85rem;
  color: var(--color-muted);
}

/* Footer */

.site-footer {
  background: var(--color-footer-bg);
  color: var(--color-footer-text);
  margin-top: 2rem;
}

.site-footer .wrap {
  padding: 1.75rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  font-size: 0.8rem;
}

.site-footer p {
  margin: 0;
}

.site-footer nav a {
  margin-left: 1rem;
  color: var(--color-footer-text);
}

.site-footer nav a:hover {
  color: #fff;
}

@media (max-width: 480px) {
  .site-footer .wrap {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-footer nav a:first-child {
    margin-left: 0;
  }
}