:root {
  --accent: #2a5bff;
  --accent-hover: #1e4acc;
  --fg: #1a1a1a;
  --fg-muted: #5a5a5a;
  --bg: #f7f7f5;
  --card-bg: #ffffff;
  --border: #e4e4e2;
  --row-alt: #fafafa;
  --font-sans: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic UI", "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body { font-family: var(--font-sans); background: var(--bg); color: var(--fg); line-height: 1.7; min-height: 100vh; }

.app-header {
  display: flex; align-items: center; gap: 14px;
  padding: 12px 16px; background: var(--card-bg); border-bottom: 1px solid var(--border);
}
.app-header h1 { font-size: 1rem; margin: 0; font-weight: 500; color: var(--fg-muted); }
.app-header .back { color: var(--fg); text-decoration: none; font-size: .9rem; }
.app-header .back:hover { color: var(--accent); }

.app-wrapper { max-width: 720px; margin: 0 auto; padding: 28px 20px 60px; }
.lede { margin: 0 0 24px; color: var(--fg-muted); font-size: .95rem; }

.form-card {
  background: var(--card-bg); border: 1px solid var(--border); border-radius: 14px;
  padding: 24px; box-shadow: 0 1px 3px rgba(0,0,0,.04); margin-bottom: 30px;
}

.date-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.field span { display: block; font-size: .85rem; color: var(--fg-muted); margin-bottom: 4px; }
.field input {
  width: 100%; padding: 10px 12px; border: 1px solid var(--border);
  border-radius: 8px; font-size: 1rem; font-family: inherit; background: #fff; color: var(--fg);
}
.field input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(42,91,255,.15); }

.format-select {
  display: flex; gap: 12px; align-items: center;
  border: 1px solid var(--border); border-radius: 10px; padding: 12px;
  margin: 16px 0 14px; flex-wrap: wrap;
}
.format-select legend { font-size: .85rem; color: var(--fg-muted); padding: 0 6px; }
.format-select label { display: flex; align-items: center; gap: 6px; cursor: pointer; font-size: .95rem; }
.format-select input { accent-color: var(--accent); }

.button-row { display: flex; gap: 10px; flex-wrap: wrap; }
button {
  padding: 11px 24px; border: none; border-radius: 10px; font-size: .95rem;
  font-weight: 600; font-family: inherit; cursor: pointer; transition: background-color .2s;
  background: var(--accent); color: #fff;
}
button:hover { background: var(--accent-hover); }
button.ghost { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
button.ghost:hover { background: var(--accent); color: #fff; }

#result h2 { font-size: 1.1rem; margin: 0 0 12px; }
#display-area { background: var(--card-bg); border: 1px solid var(--border); border-radius: 10px; padding: 16px; min-height: 80px; }

table { width: 100%; border-collapse: collapse; font-size: .95rem; }
th, td { padding: 10px 12px; text-align: left; border-bottom: 1px solid var(--border); }
th { background: #fafafa; color: var(--fg-muted); font-weight: 600; }
tr:nth-child(even) td { background: var(--row-alt); }

.data-display {
  white-space: pre-wrap; word-break: break-word;
  margin: 0; font-family: "SF Mono", "Menlo", "Consolas", monospace;
  font-size: .9rem; background: #fafafa; padding: 12px; border-radius: 6px;
}

.empty-msg { color: var(--fg-muted); font-size: .9rem; text-align: center; margin: 20px 0; }
.empty-msg.hidden { display: none; }

.wp-content {
  margin: 40px 0 0; color: var(--fg-muted); line-height: 1.9;
}
.wp-content h2 {
  font-size: 1.1rem; color: var(--fg); margin: 24px 0 10px;
  padding-top: 16px; border-top: 1px solid var(--border);
}
.wp-content p { margin: 0 0 12px; }
.wp-content .note { font-size: .85rem; opacity: .8; }

@media (max-width: 520px) {
  .app-wrapper { padding: 20px 14px 40px; }
  .form-card { padding: 18px; }
  .date-row { grid-template-columns: 1fr; }
}