:root {
  --bg: #f6f7fb;
  --panel: #ffffff;
  --border: #e1e4eb;
  --text: #1f2430;
  --muted: #6b7280;
  --accent: #3f51b5;
  --accent-fg: #ffffff;
  --status-not-started: #9ca3af;
  --status-in-progress: #2563eb;
  --status-blocked: #dc2626;
  --status-done: #16a34a;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
}

.header {
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.header h1 { margin: 0; font-size: 18px; }
.header .meta { display: flex; align-items: center; gap: 12px; color: var(--muted); }
.header button {
  background: var(--accent);
  color: var(--accent-fg);
  border: 0;
  padding: 6px 14px;
  border-radius: 6px;
  cursor: pointer;
}
.header button:hover { opacity: 0.9; }

.summary {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  padding: 16px 24px;
}
.stat-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
}
.stat-label { color: var(--muted); font-size: 12px; }
.stat-value { font-size: 24px; font-weight: 600; margin-top: 4px; }
.stat-progress { border-left: 3px solid var(--status-in-progress); }
.stat-blocked { border-left: 3px solid var(--status-blocked); }
.stat-done { border-left: 3px solid var(--status-done); }
.stat-pending { border-left: 3px solid var(--status-not-started); }

.tabs {
  display: flex;
  gap: 4px;
  padding: 0 24px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}
.tab {
  background: transparent;
  border: 0;
  padding: 12px 20px;
  cursor: pointer;
  color: var(--muted);
  border-bottom: 2px solid transparent;
  font-size: 14px;
}
.tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  font-weight: 600;
}

.task-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 12px;
  padding: 20px 24px 40px;
}

.task-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.task-card h3 { margin: 0; font-size: 15px; }
.task-card .desc { color: var(--muted); font-size: 12px; line-height: 1.5; }
.task-card .row { display: flex; justify-content: space-between; font-size: 12px; color: var(--muted); }
.task-card .row strong { color: var(--text); font-weight: 500; }
.task-card .actions { display: flex; justify-content: flex-end; }
.task-card button {
  background: transparent;
  border: 1px solid var(--border);
  padding: 4px 12px;
  border-radius: 6px;
  cursor: pointer;
  color: var(--text);
}
.task-card button:hover { background: var(--bg); }

.status-pill {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 11px;
  color: white;
  font-weight: 500;
}
.status-not_started { background: var(--status-not-started); }
.status-in_progress { background: var(--status-in-progress); }
.status-blocked { background: var(--status-blocked); }
.status-done { background: var(--status-done); }

.notes {
  background: var(--bg);
  padding: 6px 8px;
  border-radius: 4px;
  font-size: 12px;
  white-space: pre-wrap;
  color: var(--text);
}

.edit-dialog {
  border: 0;
  border-radius: 10px;
  padding: 24px;
  width: min(480px, 92vw);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.18);
}
.edit-dialog::backdrop { background: rgba(0, 0, 0, 0.4); }
.edit-dialog h2 { margin: 0 0 12px; font-size: 16px; }
.edit-dialog label {
  display: block;
  margin: 10px 0;
  font-size: 12px;
  color: var(--muted);
}
.edit-dialog input,
.edit-dialog select,
.edit-dialog textarea {
  width: 100%;
  margin-top: 4px;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  font-family: inherit;
  color: var(--text);
}
.dialog-buttons {
  margin-top: 16px;
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}
.dialog-buttons button {
  padding: 8px 16px;
  border-radius: 6px;
  border: 1px solid var(--border);
  cursor: pointer;
  background: var(--panel);
}
#edit-save { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
.error { color: var(--status-blocked); font-size: 12px; margin-top: 8px; }