@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
  --bg-color: #f8fafc;
  --text-main: #0f172a;
  --text-sub: #64748b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --card-bg: rgba(255, 255, 255, 0.8);
  --card-border: rgba(255, 255, 255, 1);
  --glass-shadow: 0 4px 16px rgba(15, 23, 42, 0.04);
  --nav-bg: rgba(255, 255, 255, 0.85);
  --radius: 16px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Kaku Gothic ProN', 'Meiryo', sans-serif;
  background: var(--bg-color);
  background-image:
    radial-gradient(at 0% 0%, hsla(217, 100%, 95%, 1) 0px, transparent 50%),
    radial-gradient(at 100% 100%, hsla(250, 100%, 95%, 1) 0px, transparent 50%);
  background-attachment: fixed;
  margin: 0;
  padding: 0;
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  padding: 24px 24px;
  text-align: center;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
}

header h1 {
  margin: 0 0 20px 0;
  font-size: 2rem;
  font-weight: 700;
  background: linear-gradient(135deg, #2563eb, #7c3aed);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  letter-spacing: -0.5px;
}

nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

nav a {
  color: var(--text-sub);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 8px 18px;
  border-radius: 100px;
  transition: all 0.3s ease;
  background: transparent;
  border: 1px solid transparent;
}

nav a:hover {
  color: var(--accent);
  background: rgba(59, 130, 246, 0.08);
}

nav a.active {
  color: #fff;
  background: var(--accent);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

main {
  padding: 48px 20px 80px;
  max-width: 900px;
  margin: 0 auto;
  flex: 1;
  width: 100%;
  box-sizing: border-box;
}

section h2 {
  font-size: 1.5rem;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.5px;
}

section h2::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 24px;
  background: linear-gradient(180deg, #3b82f6, #8b5cf6);
  border-radius: 6px;
  margin-right: 14px;
}

/* Grid layout for standard links */
.links {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
  margin-bottom: 56px;
}

.link a {
  display: flex;
  align-items: center;
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--card-border);
  padding: 20px 24px;
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text-main);
  font-weight: 600;
  font-size: 1.05rem;
  box-shadow: var(--glass-shadow);
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  position: relative;
  overflow: hidden;
}

.link a::after {
  content: '→';
  position: absolute;
  right: 24px;
  opacity: 0;
  transform: translateX(-15px);
  transition: all 0.3s ease;
  color: var(--accent);
  font-weight: 700;
}

.link a:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.08);
  border-color: rgba(59, 130, 246, 0.2);
  color: var(--accent);
}

.link a:hover::after {
  opacity: 1;
  transform: translateX(0);
}

/* Link Card layout for index.html */
.link-card {
  display: flex;
  align-items: center;
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  box-shadow: var(--glass-shadow);
  padding: 24px;
  margin-bottom: 24px;
  text-decoration: none;
  color: var(--text-main);
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  gap: 24px;
  position: relative;
  overflow: hidden;
}

.link-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 32px rgba(15, 23, 42, 0.08);
  border-color: rgba(59, 130, 246, 0.2);
}

.banner {
  width: 100px;
  height: 80px;
  background: linear-gradient(135deg, #eff6ff, #f3e8ff);
  border-radius: 12px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--accent);
  font-size: 1.1rem;
  letter-spacing: 0.5px;
  box-shadow: inset 0 2px 4px rgba(255, 255, 255, 0.8), 0 2px 8px rgba(0, 0, 0, 0.04);
}

.link-text {
  flex: 1;
}

.link-text-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-main);
  transition: color 0.3s ease;
  letter-spacing: -0.3px;
}

.link-card:hover .link-text-title {
  color: var(--accent);
}

.link-text-desc {
  font-size: 0.85rem;
  color: var(--text-sub);
  background: #f1f5f9;
  padding: 4px 12px;
  border-radius: 12px;
  display: inline-block;
  margin: 0 8px 8px 0;
  font-weight: 500;
  border: 1px solid #e2e8f0;
}

footer {
  text-align: center;
  color: var(--text-sub);
  margin-top: auto;
  padding: 24px 0;
  font-size: 0.95rem;
}

/* About Section Styles */
.about-section {
  margin-bottom: 80px;
}

.about-card {
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--card-border);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--glass-shadow);
  line-height: 1.8;
}

.about-card p {
  margin: 0 0 16px 0;
}

.about-card p:last-child {
  margin-bottom: 0;
}

.about-card .contact a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
  transition: color 0.3s ease;
}

.about-card .contact a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}