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

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

body {
  background-color: #080808;
  color: #f0f0f0;
  font-family: 'Poppins', sans-serif;
  line-height: 1.6;
  overflow-x: hidden;
}

/* ==== HEADER ==== */
header {
  background: linear-gradient(90deg, #000000, #0a0a0a, #000000);
  padding: 25px 0;
  text-align: center;
  border-bottom: 2px solid #00c3ff;
  box-shadow: 0 0 15px #00c3ff55;
}

header h1 {
  color: #00c3ff;
  text-shadow: 0 0 10px #00c3ff, 0 0 20px #0099ff;
  letter-spacing: 2px;
  margin-bottom: 10px;
}

nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: 25px;
}

nav a {
  color: #ccc;
  text-decoration: none;
  font-weight: 600;
  transition: all 0.3s ease;
  padding: 5px 10px;
  border-radius: 6px;
}

nav a:hover,
nav a.active {
  color: #00c3ff;
  box-shadow: 0 0 10px #00c3ff;
}

/* ==== MAIN CONTENT ==== */
main {
  padding: 50px 20px;
  text-align: center;
  animation: fadeIn 1.5s ease-in-out;
}

h2 {
  color: #00c3ff;
  margin-bottom: 20px;
  text-shadow: 0 0 10px #00c3ff77;
}

/* ==== ABOUT (自己紹介) ==== */
.about p {
  margin: 10px 0;
  color: #ddd;
  font-size: 1.1rem;
  letter-spacing: 1px;
}

/* ==== CARDS (プログラミングページ) ==== */
.cards {
  display: flex;
  justify-content: center;
  gap: 25px;
  flex-wrap: wrap;
  margin-top: 40px;
}

.card {
  background: #111;
  border: 1px solid #222;
  border-radius: 15px;
  width: 250px;
  padding: 25px;
  transition: all 0.4s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: conic-gradient(from 0deg, transparent, #00c3ff, transparent 30%);
  animation: rotate 4s linear infinite;
  opacity: 0.4;
}

.card h3 {
  color: #00c3ff;
  margin-bottom: 10px;
  position: relative;
  z-index: 1;
}

.card p {
  color: #ccc;
  font-size: 0.95rem;
  position: relative;
  z-index: 1;
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: 0 0 20px #00c3ff55;
}

/* ==== BUTTON ==== */
a.button {
  display: inline-block;
  margin-top: 40px;
  padding: 12px 40px;
  border: 2px solid #00c3ff;
  color: #00c3ff;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 600;
  transition: all 0.3s ease;
  letter-spacing: 1px;
}

a.button:hover {
  background-color: #00c3ff;
  color: #000;
  box-shadow: 0 0 20px #00c3ff;
  transform: scale(1.05);
}

/* ==== ANIMATIONS ==== */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes rotate {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}