*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #f9fafb;
  --surface: #ffffff;
  --border: #e5e7eb;
  --text: #111827;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --danger: #dc2626;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,.08);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

/* ── layout ── */
.view { display: none; }
.view.active { display: block; }

.container {
  max-width: 640px;
  margin: 0 auto;
  padding: 1.5rem 1rem;
}

/* ── auth views ── */
.auth-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 2rem;
  margin-top: 4rem;
}
.auth-card h1 { font-size: 1.5rem; margin-bottom: 0.5rem; }
.auth-card p  { color: var(--muted); margin-bottom: 1.5rem; font-size: 0.9rem; }

/* ── main app ── */
header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}
header h1 { font-size: 1.4rem; flex: 1; }

/* ── forms ── */
input[type="text"],
input[type="email"] {
  width: 100%;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 1rem;
  background: var(--surface);
  color: var(--text);
  outline: none;
  transition: border-color 0.15s;
}
input:focus { border-color: var(--accent); }

select {
  padding: 0.55rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.9rem;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}

button {
  padding: 0.55rem 1rem;
  border: none;
  border-radius: var(--radius);
  font-size: 0.9rem;
  cursor: pointer;
  font-weight: 500;
  transition: background 0.15s, opacity 0.15s;
}
button:disabled { opacity: 0.5; cursor: default; }

.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover:not(:disabled) { background: var(--accent-hover); }

.btn-ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover:not(:disabled) { background: var(--border); color: var(--text); }

.btn-danger {
  background: transparent;
  color: var(--danger);
  border: 1px solid transparent;
  padding: 0.2rem 0.4rem;
  font-size: 0.8rem;
}
.btn-danger:hover { background: #fef2f2; }

/* ── add-item form ── */
#add-item-form {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}
#add-item-form input { flex: 1; min-width: 140px; }

/* ── sections ── */
#sections-container { display: flex; flex-direction: column; gap: 0.5rem; }

details {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

summary {
  padding: 0.7rem 1rem;
  font-weight: 600;
  cursor: pointer;
  user-select: none;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
summary::-webkit-details-marker { display: none; }
summary::before {
  content: "▶";
  font-size: 0.65rem;
  color: var(--muted);
  transition: transform 0.15s;
  display: inline-block;
  width: 1em;
}
details[open] summary::before { transform: rotate(90deg); }

.section-count {
  margin-left: auto;
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--muted);
  background: var(--bg);
  padding: 0.1rem 0.45rem;
  border-radius: 999px;
  border: 1px solid var(--border);
}

/* ── items ── */
.item-list { padding: 0 0 0.25rem; }

.item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.55rem 1rem;
  border-top: 1px solid var(--border);
  transition: opacity 0.4s, text-decoration 0.1s;
}
.item input[type="checkbox"] { flex-shrink: 0; width: 1.1rem; height: 1.1rem; cursor: pointer; accent-color: var(--accent); }
.item-text { flex: 1; font-size: 0.95rem; }

.item.checked .item-text {
  text-decoration: line-through;
  color: var(--muted);
}
.item.fading { opacity: 0; }

/* classifying placeholder */
.classifying-label {
  font-size: 0.75rem;
  color: var(--muted);
  font-style: italic;
  margin-left: auto;
}

/* ── modal / dialog ── */
dialog {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 8px 32px rgba(0,0,0,.15);
  padding: 1.5rem;
  min-width: 320px;
  max-width: 90vw;
}
dialog::backdrop { background: rgba(0,0,0,0.35); }
dialog h2 { margin-bottom: 1rem; font-size: 1.1rem; }
dialog .dialog-actions { display: flex; gap: 0.5rem; justify-content: flex-end; margin-top: 1rem; }

.section-list-items { list-style: none; margin-bottom: 1rem; max-height: 200px; overflow-y: auto; }
.section-list-items li {
  padding: 0.35rem 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.9rem;
  color: var(--text);
}
.section-list-items li:last-child { border-bottom: none; }

.add-section-row { display: flex; gap: 0.5rem; margin-top: 0.5rem; }
.add-section-row input { flex: 1; }

.error-msg {
  color: var(--danger);
  font-size: 0.85rem;
  margin-top: 0.4rem;
}

/* ── responsive ── */
@media (max-width: 480px) {
  header { gap: 0.5rem; }
  button { padding: 0.5rem 0.7rem; font-size: 0.85rem; }
}