/* ===== 全体レイアウトと基本設定 ===== */
body {
  font-family: 'Helvetica Neue', 'Segoe UI', sans-serif;
  background-color: #fafafa;
  color: #333;
  margin: 0;
  padding: 40px 20px;
  text-align: center;
  box-sizing: border-box;
}

h1 {
  font-size: 2.5rem;
  color: #2c3e50;
  margin-bottom: 40px;
  letter-spacing: 1px;
}

/* ===== タブ切り替え ===== */
.tab-container {
  display: flex;
  justify-content: center;
  margin-bottom: 30px;
  gap: 12px;
  flex-wrap: wrap;
}

.tab {
  padding: 12px 24px;
  border: 2px solid #3498db;
  border-radius: 30px;
  background-color: transparent;
  color: #3498db;
  font-weight: 600;
  cursor: pointer;
  transition: 0.3s ease;
}

.tab.active {
  background-color: #3498db;
  color: #fff;
  transform: translateY(-2px);
}

.tab:hover {
  background-color: #2980b9;
  color: #fff;
}

.tab-content {
  display: none;
  margin-top: 30px;
}

.tab-content.active {
  display: block;
}

/* ===== ファイル選択スタイル ===== */
.file-button {
  display: inline-block;
  padding: 12px 24px;
  background-color: #27ae60;
  color: #fff;
  border-radius: 30px;
  cursor: pointer;
  font-size: 15px;
  margin: 10px;
  transition: 0.3s ease;
}

.file-button:hover {
  background-color: #219150;
  transform: translateY(-2px);
}

input[type="file"] {
  display: none;
}

/* ===== ラベル名表示 ===== */
.file-name {
  font-size: 15px;
  color: #555;
  display: inline-block;
  margin-left: 12px;
  vertical-align: middle;
  font-weight: 500;
}

/* ===== ボタン共通 ===== */
button {
  padding: 10px 20px;
  font-size: 15px;
  background-color: #3498db;
  color: #fff;
  border: none;
  border-radius: 30px;
  cursor: pointer;
  margin: 10px 5px;
  transition: 0.3s ease;
}

button:hover {
  background-color: #2980b9;
  transform: translateY(-2px);
}

.action-btn {
  margin-top: 20px;
}

/* ===== canvas スタイル ===== */
canvas {
  margin-top: 30px;
  max-width: 100%;
  max-height: 80vh;
  border: 2px solid #ddd;
  border-radius: 12px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}

/* ===== LUT 強度スライダー ===== */
.slider-group {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin: 20px 0;
}

input[type="range"] {
  width: 60%;
  margin: 10px 0;
  accent-color: #2ecc71;
}

#intensityValue, #intensityValue2 {
  font-weight: 600;
  color: #2ecc71;
}

/* ===== LUTボタン・モード切替ボタン ===== */
.button-group {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  margin: 20px 0;
}

.mode-btn,
.button-group button {
  padding: 8px 16px;
  background: #ecf0f1;
  border: 1px solid #ccc;
  border-radius: 20px;
  cursor: pointer;
  transition: 0.2s ease;
}

.mode-btn.active,
.button-group button.active {
  background: #e67e22;
  color: white;
  border-color: #e67e22;
}

/* 元画像に戻すボタン特化 */
#resetToOriginal1 {
  background-color: #2196f3;
  color: white;
  border: none;
}

#resetToOriginal1:hover {
  background-color: #1976d2;
}

/* ===== サムネイル ===== */
.thumbnail-container {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  margin: 20px 0;
}

.thumbnail {
  width: 100px;
  height: 100px;
  border-radius: 8px;
  border: 2px solid transparent;
  margin: 5px;
  cursor: pointer;
  transition: 0.3s ease;
  object-fit: contain; /* 縦横比を保ちつつ、枠内に収める */
  background-color: #fff; /* 余白が目立たないように */
}


.thumbnail:hover {
  border-color: #2ecc71;
  transform: scale(1.05);
}

.thumbnail.selected {
  border: 2px solid #2196f3;
}

.thumbnail.active {
  border: 3px solid #00ff88;
  box-shadow: 0 0 10px #00ff88;
  border-radius: 6px;
}

/* ===== アップロードグループ ===== */
.upload-group {
  margin: 20px 0;
}

.navigation-buttons {
  margin: 20px 0;
}

/* ===== アニメーション効果（滑らかさ） ===== */
* {
  transition: all 0.2s ease-in-out;
}

/* ===== メディアクエリ（レスポンシブ） ===== */
@media screen and (max-width: 768px) {
  .tab-container {
    flex-direction: column;
  }

  .button-group,
  .slider-group,
  .navigation-buttons,
  .thumbnail-container {
    flex-direction: column;
    align-items: center;
  }

  input[type="range"] {
    width: 90%;
  }

  canvas {
    width: 100% !important;
    height: auto !important;
  }
}

/* ボタンの共通スタイル */
.nav-btn {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: #3498db;
  display: flex;
  justify-content: center;
  align-items: center;
  border: none;
  cursor: pointer;
  transition: 0.3s ease;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.nav-btn:hover {
  background-color: #2980b9;
  transform: scale(1.1);
}

/* 三角形アイコンのスタイル */
.triangle {
  width: 0;
  height: 0;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
}

.triangle.left {
  border-right: 15px solid white; /* 左向き */
}

.triangle.right {
  border-left: 15px solid white; /* 右向き */
}

/* ボタン行のスタイル */
.button-row {
  display: flex;
  justify-content: center;
  gap: 20px;
}