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

body {
  font-family: "Noto Sans JP", "Helvetica Neue", sans-serif;
  background-color: #fafafa;
  color: #333;
  line-height: 1.8;
}

/* ======= Header ======= */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 60px;
  background-color: #fff;
  border-bottom: 1px solid #e0e0e0;
  position: sticky;
  top: 0;
  z-index: 1000;
}

header h1 {
  font-size: 1.5rem;
  font-weight: 600;
  color: #222;
}

nav a {
  color: #555;
  text-decoration: none;
  margin-left: 25px;
  font-weight: 500;
  transition: color 0.2s;
}

nav a:hover {
  color: #0070c9;
}

/* ======= Hero Section ======= */
.hero {
  text-align: center;
  padding: 120px 20px 100px;
  background-color: #f4f4f4;
}

.hero h2 {
  font-size: 2.6rem;
  font-weight: 600;
  margin-bottom: 15px;
  color: #222;
}

.hero p {
  font-size: 1.1rem;
  color: #555;
  margin-bottom: 30px;
}

.hero button {
  background-color: #0070c9;
  color: #fff;
  border: none;
  padding: 12px 28px;
  font-size: 1rem;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.3s, transform 0.2s;
}

.hero button:hover {
  background-color: #005fa3;
  transform: translateY(-2px);
}

/* ======= Projects Section ======= */
section#projects {
  padding: 80px 10%;
  background-color: #fff;
}

section#projects h3 {
  text-align: center;
  color: #222;
  font-size: 1.8rem;
  margin-bottom: 50px;
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
}

.project-card {
  background-color: #f8f8f8;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  padding: 25px;
  transition: box-shadow 0.3s, transform 0.2s;
}

.project-card:hover {
  box-shadow: 0 6px 15px rgba(0, 0, 0, 0.1);
  transform: translateY(-3px);
}

/* When a project card is an anchor, make the whole card clickable and remove default link styles */
a.project-card {
  display: block; /* allow padding and block layout */
  text-decoration: none; /* remove underline */
  color: inherit; /* inherit color so headings keep their color */
  cursor: pointer;
}

/* Provide a visible focus style for keyboard users */
a.project-card:focus {
  outline: 3px solid rgba(0, 112, 201, 0.25);
  outline-offset: 3px;
}

.project-card h4 {
  color: #0070c9;
  margin-bottom: 10px;
}

.project-card p {
  color: #555;
}

/* ======= About Section ======= */
section#about {
  padding: 100px 10%;
  background-color: #f4f4f4;
  text-align: center;
}

section#about h3 {
  font-size: 1.8rem;
  color: #222;
  margin-bottom: 30px;
}

section#about p {
  max-width: 700px;
  margin: 0 auto;
  color: #555;
  font-size: 1rem;
}

/* ======= Footer ======= */
footer {
  text-align: center;
  padding: 30px;
  font-size: 0.9rem;
  color: #777;
  background-color: #fff;
  border-top: 1px solid #e0e0e0;
}