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

body {
  background-color: #e8e7e6; 
  font-family: 'Hiragino Kaku Gothic Pro', 'ヒラギノ角ゴ Pro W3', Meiryo, sans-serif;
  min-height: 100svh;
  padding: 20px;
}

h1 {
  text-align: center;
  color: #333;
  margin-bottom: 40px;
  font-size: 2em;
}

.contact-section h2 {
  color: #555555;
  margin-bottom: 20px;
  font-size: 1.5em;
}

.twitter-button {
  display: inline-block;
  background: #1DA1F2;
  color: white;
  padding: 12px 30px;
  text-decoration: none;
  border-radius: 50px;
  font-weight: bold;
  transition: background 0.3s;
}

.twitter-button:hover {
  background: #1a8cd8;
}

.works-section h2 {
  color: #555555;
  margin-bottom: 30px;
  text-align: center;
  font-size: 1.5em;
}

.banner-container {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 15px;
  max-width: 700px;
  margin: 0 auto;
}

.banner {
  display: block;
  color: #2e2d2d;
  padding: 20px;
  text-decoration: none;
  border-radius: 10px;
  text-align: center;
  font-size: 1.2em;
  font-weight: bold;
  transition: transform 0.3s, box-shadow 0.3s;
  box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.banner:hover {
  transform: translateY(-5px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}

.banner-dev {
  background: #858585;
  color: #333;
  cursor: default;
  box-shadow: inset 0 0 0 2px rgba(255,255,255,0.6);
  position: relative;
}

.banner-dev:hover {
  transform: none;
  box-shadow: inset 0 0 0 2px rgba(255,255,255,0.6);
}

.banner-dev::before {
  content: "";
  position: absolute;
  inset: 6px;
  border-radius: 6px;
  pointer-events: none;
}


@media (max-width: 600px) {
  .container {
    padding: 20px;
  }
  
  h1 {
    font-size: 1.5em;
  }
  
  .banner {
    font-size: 1em;
  }
  
  .banner-container {
    grid-template-columns: 1fr;
  }
}
/* 外枠：白 → 内側：黒の丸枠だけCSSで描画 */
.twitter-link{
  display:flex;
  justify-content:center;
  align-items:center;
  width:48px;
  height:48px;
  border-radius:50%;
  background:#000;               /* 黒丸 */
  box-shadow:0 0 0 3px #fff;     /* 白い縁取り */
  overflow:hidden;
  text-decoration:none;

  position: fixed;   /* ← 画面に固定 */
  bottom: 20px;      /* ← 下からの距離 */
  left: 50%;         /* ← 画面中央に寄せる */
  transform: translateX(-50%); /* ← 左右中央揃え */
}

/* ロゴ画像（白いPNG想定） */
.twitter-icon{
  width:60%;
  height:60%;
  object-fit:contain;
  display:block;
  -webkit-user-drag:none;
  user-select:none;
  filter:drop-shadow(0 0 1px #fff); /* ダークモードでの視認性を少し補強 */
}

/* ちょっとだけ反応 */
.twitter-link:hover .twitter-icon,
.twitter-link:focus .twitter-icon{
  transform:scale(0.9);
}
.twitter-link:focus{
  outline:2px solid #1DA1F2;
  outline-offset:3px;
}