/* ===== ベース ===== */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f7f9fc;
  color: #111;
  line-height: 1.6;
}

/* ===== 共通幅 ===== */
.container,
.site-header,
.site-footer {
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== 本文ボックス ===== */
.container {
  margin-top: 20px;
  padding: 20px;
  background: #fff;
  border: 1px solid #eee;
  border-radius: 10px;
}

/* ===== ヘッダー ===== */
.site-header {
  background: rgba(255,255,255,0.9);
  backdrop-filter: blur(6px);
  border: 1px solid #eee;
  position: sticky;
  top: 16px;
  z-index: 1000;
  margin-top: 16px;
  border-radius: 10px;
}

.header-inner {
  padding: 14px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo a {
  text-decoration: none;
  font-size: 22px;
  font-weight: 700;
  color: #111;
}

.logo span {
  color: #2196f3;
}

.nav {
  display: flex;
  gap: 18px;
}

.nav a {
  text-decoration: none;
  font-size: 13px;
  color: #555;
  position: relative;
}

.nav a:hover {
  color: #2196f3;
}

.nav a::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0%;
  height: 2px;
  background: #2196f3;
  transition: 0.2s;
}

.nav a:hover::after {
  width: 100%;
}

/* ===== コンテンツ ===== */
h1 {
  font-size: 24px;
  font-weight: 600;
}

.desc {
  font-size: 14px;
  color: #555;
  margin-bottom: 20px;
}

.tool-wrapper {
  background: #fff;
  padding: 20px;
  border-radius: 10px;
  border: 1px solid #eee;
}

.tool-wrapper input[type="file"] {
  margin-bottom: 14px;
}

.tool-wrapper button,
.result-area button {
  display: inline-block;
  border: none;
  background: #2196f3;
  color: #fff;
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
}

.tool-wrapper button:hover,
.result-area button:hover {
  opacity: 0.9;
}

.result-area {
  margin-top: 20px;
}

#result-message {
  font-size: 14px;
  color: #333;
  margin-bottom: 10px;
}

.t-empty {
  font-size: 13px;
  color: #777;
}

.ad {
  margin: 28px 0;
  text-align: center;
}

/* ===== フッター ===== */
.site-footer {
  margin-top: 40px;
  border: 1px solid #eee;
  background: #fff;
  border-radius: 10px;
}

.footer-inner {
  padding: 24px 20px;
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 18px;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 12px;
  color: #666;
  text-decoration: none;
}

.footer-links a:hover {
  color: #2196f3;
}

.footer-copy {
  font-size: 11px;
  color: #999;
}

/* ===== 関連ツール ===== */
.related-tools {
  margin-top: 40px;
}

.related-tools h2 {
  font-size: 16px;
  margin-bottom: 12px;
}

.related-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.related-list a {
  font-size: 13px;
  padding: 8px 12px;
  background: #fff;
  border: 1px solid #eee;
  border-radius: 8px;
  text-decoration: none;
  color: #333;
}

.related-list a:hover {
  border-color: #2196f3;
  color: #2196f3;
}