/* Google Fontsから日本語フォントを読み込み */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;700&display=swap');

/* --- グラデーション背景テーマ --- */
:root {
  --color-foreground: #ffffff;
  --color-heading: #ffffff;
  --color-accent: #ffd700;
  --font-default: 'Noto Sans JP', 'Hiragino Kaku Gothic ProN', 'Meiryo', sans-serif;
}

section {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  color: var(--color-foreground);
  font-family: var(--font-default);
  font-weight: 400;
  box-sizing: border-box;
  position: relative;
  line-height: 1.7;
  font-size: 22px;
  padding: 56px;
}

/* スライドごとに異なるグラデーション */
section:nth-child(2n) {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

section:nth-child(3n) {
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

section:nth-child(4n) {
  background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

section:nth-child(5n) {
  background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  color: var(--color-heading);
  margin: 0;
  padding: 0;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

h1 {
  font-size: 56px;
  line-height: 1.4;
  text-align: left;
}

h2 {
  position: absolute;
  top: 40px;
  left: 56px;
  right: 56px;
  font-size: 40px;
  padding-top: 0;
  padding-bottom: 16px;
}

h2::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 8px;
  width: 80px;
  height: 3px;
  background-color: var(--color-accent);
  box-shadow: 0 2px 10px rgba(255, 215, 0, 0.5);
}

h2 + * {
  margin-top: 112px;
}

h3 {
  color: var(--color-accent);
  font-size: 28px;
  margin-top: 32px;
  margin-bottom: 12px;
  text-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}

ul, ol {
  padding-left: 32px;
}

li {
  margin-bottom: 10px;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

footer {
  font-size: 16px;
  color: rgba(255, 255, 255, 0.7);
  position: absolute;
  left: 56px;
  right: 56px;
  bottom: 40px;
  text-align: center;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

section.lead {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
}

section.lead h1 {
  margin-bottom: 24px;
  text-align: center;
}

section.lead p {
  font-size: 24px;
  color: var(--color-foreground);
  text-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}

/* 半透明の背景ボックス */
.text-box {
  background-color: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  padding: 20px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

/* 強調テキスト */
strong {
  color: var(--color-accent);
  font-weight: 700;
  text-shadow: 0 1px 5px rgba(0, 0, 0, 0.3);
}

/* コード */
code {
  background-color: rgba(0, 0, 0, 0.3);
  color: var(--color-accent);
  padding: 2px 8px;
  border-radius: 4px;
}