/* base.css - 全ページ共通スタイル */

:root {
  --clr-bg:       #1e1e1e;
  --clr-card:     #2a2d2d;
  --clr-text:     #fafafa;
  --clr-primary:  #4a7cb0;
  --clr-accent:   #81d4fa;
  --clr-link:     #45e06f;
  --clr-shadow:   rgba(0,0,0,0.7);
  --clr-gradient: linear-gradient(135deg, #1a2a6c, #2a4d69, #3a7bd5);

  --font-heading: sans-serif;
  --font-body:    sans-serif;

  --radius:       12px;
  --transition:   0.3s;

  --spacing-xs:   0.25rem;
  --spacing-sm:   0.5rem;
  --spacing-md:   1rem;
  --spacing-lg:   2rem;
  --spacing-xl:   4rem;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  overflow-y: scroll;
  color-scheme: dark light;
  forced-color-adjust: none;
}

body {
  font-family: var(--font-body);
  background: var(--clr-bg);
  color: var(--clr-text);
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-weight: 400;
  letter-spacing: 0.02em;
  display: flex;
  flex-direction: column;
}

h1, h2, h3, h4, h5, h6,
.section-title,
.logo {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-weight: 700;
  letter-spacing: 0.03em;
}

@media (max-width: 768px) {
  body {
    font-size: 15px;
  }

  header .container {
    padding: var(--spacing-sm) var(--spacing-md);
  }

  .container {
    padding: 0 var(--spacing-md);
  }

  main {
    padding: 0;
  }

  .section-title {
    font-size: 2rem;
  }
}

@media (max-width: 480px) {
  .section-title {
    font-size: 1.8rem;
  }

  main {
    padding: 0;
  }
}

/* shared page title styling for all pages */
.page-title-section {
  padding: 2rem 1.5rem 1.5rem;
  text-align: center;
  position: relative;
}

@media (max-width: 768px) {
  .page-title-section {
    padding: 1.5rem 1rem 1rem;
  }

  .page-title {
    font-size: 1.6rem;
  }
}

@media (max-width: 480px) {
  .page-title-section {
    padding: 1.2rem 0.75rem 0.75rem;
  }

  .page-title {
    font-size: 1.4rem;
  }
}

.page-title {
  font-family: var(--font-heading);
  font-size: 2rem;
  color: var(--clr-accent);
  margin: 0;
  letter-spacing: 0.05em;
  position: relative;
  display: inline-block;
  padding-bottom: 1rem;
}

.page-title::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60%;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--clr-accent), transparent);
  border-radius: 2px;
}

.page-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 20%;
  height: 1px;
  background: rgba(129, 212, 250, 0.3);
  border-radius: 1px;
}


.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--clr-primary);
  color: white;
  padding: var(--spacing-sm);
  z-index: 1000;
  transition: top 0.3s;
}

.skip-link:focus {
  top: 0;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--clr-accent);
  outline-offset: 2px;
}

nav#nav a,
button {
  min-height: 44px;
  min-width: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* ヘッダー */
header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(42, 45, 45, 0.9);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 8px var(--clr-shadow);
  z-index: 100;
  transition: background 0.3s ease;
}

header.scrolled {
  background: rgba(42, 45, 45, 0.98);
}

header .container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) var(--spacing-lg);
}

.logo {
  font-family: var(--font-heading);
  font-size: 1.8rem;
  color: var(--clr-accent);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0;
}

nav#nav ul#header-menu {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: var(--spacing-md);
}

nav#nav li {
  list-style: none;
}

nav#nav a {
  color: var(--clr-text);
  text-decoration: none;
  padding: var(--spacing-xs) var(--spacing-sm);
  position: relative;
  font-weight: 500;
}

nav#nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--clr-accent);
  transition: width var(--transition), left var(--transition);
}

nav#nav a:hover::after,
nav#nav a:focus::after {
  width: 100%;
  left: 0;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 2rem;
  height: 2rem;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
}

.nav-toggle span {
  display: block;
  width: 2rem;
  height: 0.25rem;
  background: var(--clr-text);
  border-radius: 10px;
  transition: all 0.3s linear;
  transform-origin: center;
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(0.35rem, 0.35rem);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(0.35rem, -0.35rem);
}

@media (max-width: 768px) {
  nav#nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: rgba(42, 45, 45, 0.95);
    backdrop-filter: blur(10px);
  }
  
  nav#nav.active {
    display: block;
  }
  
  nav#nav.active ul#header-menu {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
  }
  
  .nav-toggle {
    display: flex;
  }
}

/* フッター */
footer {
  width: 100%;
  background: var(--clr-card);
  box-shadow: 0 -2px 8px var(--clr-shadow);
  padding: 0.5rem 0;
  text-align: center;
  margin-top: auto;
}

footer .container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  padding: 0 1rem;
}

.footer-logo {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  color: var(--clr-accent);
}

footer a {
  color: #fafafa;
  text-decoration: none;
  transition: color 0.3s;
}

footer a:hover {
  color: var(--clr-link);
}

.copyright {
  margin-top: var(--spacing-md);
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.9rem;
}

/* レイアウト */
main {
  flex: 1;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-lg);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* スクロールバー */
::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: var(--clr-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--clr-primary);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--clr-accent);
}

/* 共通エフェクト */
.shine-effect {
  position: relative;
  overflow: hidden;
}

.shine-effect::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  transition: 0.5s;
}

.shine-effect:hover::before {
  left: 100%;
}

.shine-white::before {
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
}

.shine-accent::before {
  background: linear-gradient(90deg, transparent, rgba(129, 212, 250, 0.2), transparent);
}

::-webkit-scrollbar-thumb {
  background: var(--clr-primary);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--clr-accent);
}

@media (max-width: 992px) {
  .section-title {
    font-size: 2rem;
  }
}

@media (max-width: 480px) {
  .section-title {
    font-size: 1.8rem;
  }
}