/* 
  学習資料ポータル 共通スタイルシート
  Design Unified with Portfolio: https://ningengakushu.com/
*/

:root {
  --bg-white: #ffffff;
  --bg-light: #fafafa;
  --text-dark: #0f172a;
  --text-muted: #64748b;
  --brand-yellow: #f5cd00;
  --border-dark: #0f172a;
  --shadow-pop: 8px 8px 0px 0px #0f172a;
  --shadow-pop-yellow: 8px 8px 0px 0px #f5cd00;
  --font-sans: 'Inter', 'Noto Sans JP', sans-serif;
  --max-width: 900px;
  --header-height: 96px;
}

/* Base Styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-white);
  color: var(--text-dark);
  font-family: var(--font-sans);
  line-height: 1.8;
  padding-top: var(--header-height);
  min-height: 100vh;
  /* Dot Pattern Background */
  background-image: radial-gradient(var(--text-dark) 0.5px, transparent 0.5px);
  background-size: 24px 24px;
}

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

/* Header & Logo */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(12px);
  z-index: 1000;
  display: flex;
  align-items: center;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

.logo {
  display: inline-block;
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: -0.05em;
  color: var(--text-dark);
  text-decoration: none;
  background: var(--bg-white);
  border: 2px solid var(--border-dark);
  padding: 0.5rem 1rem;
  border-radius: 1rem;
  box-shadow: 4px 4px 0px 0px var(--border-dark);
  transition: all 0.2s;
}

.logo:hover {
  transform: translateY(-2px);
  box-shadow: 4px 4px 0px 0px var(--brand-yellow);
}

.logo-accent {
  color: var(--brand-yellow);
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  font-size: 0.85rem;
  font-weight: 800;
  color: var(--text-dark);
  text-decoration: none;
  transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--brand-yellow);
}

/* Typography for Articles */
main {
  padding: 2rem 0 10rem;
  /* Increased bottom padding for margin */
}

.hero-section {
  text-align: center;
  margin-bottom: 3rem;
}

.hero-sub {
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
}

h1 {
  font-size: 3rem;
  font-weight: 900;
  margin-bottom: 1.5rem;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--text-dark);
  text-align: center;
}

h2 {
  font-size: 2rem;
  font-weight: 900;
  margin: 4rem 0 2rem;
  color: var(--text-dark);
  display: inline-block;
  position: relative;
}

h2::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 0;
  width: 100%;
  height: 12px;
  background: var(--brand-yellow);
  z-index: -1;
  opacity: 0.5;
}

h3 {
  font-size: 1.25rem;
  font-weight: 900;
  margin: 0 0 1rem;
  color: var(--text-dark);
}

p {
  margin-bottom: 1.5rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Article Links */
main a:not(.card):not(.tool-banner):not(.back-link):not(.logo) {
  color: var(--text-dark);
  font-weight: 800;
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
  text-decoration-color: var(--brand-yellow);
  transition: all 0.2s ease;
}

main a:not(.card):not(.tool-banner):not(.back-link):not(.logo):hover {
  background: var(--brand-yellow);
}

/* Cards for Sitemap/Index */
.category-grid,
.sitemap-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 4rem;
  list-style: none;
  padding: 0;
}

.card,
.sitemap-list li {
  background: var(--bg-white);
  border: 4px solid var(--border-dark);
  border-radius: 1.5rem;
  padding: 1.5rem;
  transition: all 0.2s ease;
  text-decoration: none;
  margin: 0;
  box-shadow: var(--shadow-pop);
  display: flex;
  flex-direction: column;
}

.sitemap-list li a {
  display: block;
  font-weight: 900;
  color: var(--text-dark);
  text-decoration: none;
  font-size: 1.2rem;
}

.card:hover,
.sitemap-list li:hover {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-pop-yellow);
}

.card h3 {
  margin-top: 0;
  margin-bottom: 0.5rem;
}

.card p {
  margin-bottom: 0;
  font-size: 0.9rem;
}

/* Search Box */
.search-container {
  margin-bottom: 3rem;
}

.search-container input {
  width: 100%;
  padding: 1.25rem 1.75rem;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-dark);
  background: var(--bg-white);
  border: 4px solid var(--border-dark);
  border-radius: 2rem;
  outline: none;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-pop);
}

.search-container input:focus {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-pop-yellow);
}

.search-container input::placeholder {
  color: var(--text-muted);
  font-weight: 500;
}

/* Back Link Style */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 2rem;
  font-size: 1rem;
  font-weight: 900;
  color: var(--text-dark) !important;
  text-decoration: none;
  background: var(--bg-white);
  border: 3px solid var(--border-dark);
  padding: 0.75rem 1.5rem;
  border-radius: 1.25rem;
  box-shadow: 4px 4px 0px 0px var(--border-dark);
  transition: all 0.2s;
}

.back-link:hover {
  transform: translate(-2px, -2px);
  box-shadow: 4px 4px 0px 0px var(--brand-yellow);
}

/* Code Blocks & Tables */
code {
  background: #f1f5f9;
  color: var(--text-dark);
  padding: 0.2rem 0.4rem;
  border-radius: 0.4rem;
  font-family: 'Fira Code', monospace;
  font-size: 0.9em;
  border: 1px solid var(--border-dark);
}

pre {
  background: #0f172a;
  padding: 1.5rem;
  border-radius: 1.25rem;
  overflow-x: auto;
  margin: 2rem 0;
  border: 4px solid var(--border-dark);
  box-shadow: 6px 6px 0px 0px var(--brand-yellow);
}

pre code {
  background: transparent;
  padding: 0;
  color: #f8fafc;
  border: none;
}

table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: 2.5rem 0;
  border: 4px solid var(--border-dark);
  border-radius: 1.5rem;
  overflow: hidden;
  box-shadow: var(--shadow-pop);
}

th,
td {
  text-align: left;
  padding: 1.25rem;
  border-bottom: 2px solid var(--border-dark);
  border-right: 2px solid var(--border-dark);
}

th:last-child,
td:last-child {
  border-right: none;
}

tr:last-child td {
  border-bottom: none;
}

th {
  background: var(--brand-yellow);
  color: var(--text-dark);
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

td {
  background: var(--bg-white);
  color: var(--text-dark);
  font-weight: 500;
}

/* Footer */
footer {
  padding: 6rem 0;
  /* More balanced padding */
  border-top: 4px solid var(--border-dark);
  text-align: center;
  background: var(--bg-white);
}

footer p {
  font-size: 0.9rem;
  font-weight: 800;
  color: var(--text-dark);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  :root {
    --header-height: 80px;
  }

  h1 {
    font-size: 2.25rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  .category-grid,
  .sitemap-list {
    grid-template-columns: 1fr;
  }
}