/* tech-ai site stylesheet */

:root {
  --primary-color: #0A4D68;
  --secondary-color: #088395;
  --accent-color: #F3AA60;
  --light-bg: #F7F7F7;
  --white: #FFFFFF;
  --text-dark: #333333;
  --text-light: #666666;
  --border-color: #EAEAEA;
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  --transition: all 0.3s ease-in-out;
}

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;700&family=Roboto:wght@700;900&display=swap');

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

body {
  font-family: 'Noto Sans JP', sans-serif;
  line-height: 1.8;
  color: var(--text-dark);
  background-color: var(--white);
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Roboto', sans-serif;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 1.5rem;
  color: var(--primary-color);
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.75rem; }

/* Header */
header {
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 80px;
}

.logo {
  font-family: 'Roboto', sans-serif;
  font-weight: 900;
  font-size: 1.8rem;
  color: var(--primary-color);
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: center;
}

.nav-menu a {
  color: var(--text-dark);
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  transition: var(--transition);
  font-weight: 700;
}

.nav-menu a:hover {
  background-color: var(--light-bg);
  color: var(--secondary-color);
}

/* Hero Section */
.hero {
  margin-top: 80px;
  height: 60vh;
  background-size: cover;
  background-position: center;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--white);
  position: relative;
}

.hero::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(45deg, rgba(10, 77, 104, 0.8), rgba(8, 131, 149, 0.7));
}

.hero-content {
  position: relative;
  z-index: 2;
}

.hero h1 {
  color: var(--white);
  font-size: 4rem;
  font-weight: 900;
  text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

.hero p {
  font-size: 1.25rem;
  max-width: 700px;
  margin: 0 auto 2rem;
  opacity: 0.9;
}

/* Main Content Layout */
.container {
  max-width: 1200px;
  margin: 4rem auto;
  padding: 0 2rem;
}

.page-wrapper {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4rem;
}

.page-wrapper.two-column {
  grid-template-columns: 3fr 1fr;
}

.main-content article h2 {
  border-bottom: 2px solid var(--secondary-color);
  padding-bottom: 0.5rem;
  margin-bottom: 2rem;
}

/* Sidebar */
.sidebar {
  position: sticky;
  top: 120px;
}

.sidebar-widget {
  margin-bottom: 2rem;
  background-color: var(--light-bg);
  padding: 1.5rem;
  border-radius: 8px;
}

.sidebar-widget h3 {
  font-size: 1.2rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}

.toc-list {
  list-style: none;
}

.toc-list a {
  text-decoration: none;
  color: var(--text-light);
  display: block;
  padding: 0.5rem 0;
  transition: var(--transition);
}

.toc-list a:hover {
  color: var(--secondary-color);
  transform: translateX(5px);
}

.ad-space {
  height: 250px;
  background-color: var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-light);
  font-size: 0.9rem;
  border-radius: 8px;
}

/* Hamburger Menu */
.hamburger-menu {
    display: none;
    cursor: pointer;
}

.hamburger-menu .bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    background-color: var(--primary-color);
    transition: var(--transition);
}

@media (max-width: 1024px) {
  .page-wrapper.two-column {
    grid-template-columns: 1fr;
  }
  .sidebar {
    position: static;
  }
}

@media (max-width: 768px) {
  h1 { font-size: 2.5rem; }
  .hero h1 { font-size: 3rem; }

  .nav-menu {
    display: none;
    position: absolute;
    top: 80px;
    left: 0;
    background-color: var(--white);
    width: 100%;
    flex-direction: column;
    padding: 1rem 0;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
  }
  .nav-menu.active {
    display: flex;
  }
  .hamburger-menu {
    display: block;
  }
}

/* Footer */
footer {
  background-color: var(--primary-color);
  color: var(--white);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
}

footer .container {
  text-align: center;
}

.footer-links {
  list-style: none;
  display: flex;
  gap: 2rem;
  justify-content: center;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--white);
  text-decoration: none;
  transition: var(--transition);
  font-size: 0.95rem;
}

.footer-links a:hover {
  color: var(--accent-color);
}

footer p {
  font-size: 0.9rem;
  opacity: 0.8;
}

@media (max-width: 768px) {
  .footer-links {
    flex-direction: column;
    gap: 0.5rem;
  }
}