:root {
  --bg: #0f1117;
  --surface: #1a1d27;
  --surface2: #22263a;
  --border: #2e3250;
  --accent: #4f8ef7;
  --accent2: #7c5cbf;
  --text: #e8eaf0;
  --text-muted: #8b90a8;
  --success: #3ecf8e;
  --error: #f87171;
  --radius: 12px;
  --shadow: 0 4px 24px rgba(0,0,0,0.4);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Layout ── */
.container { max-width: 900px; margin: 0 auto; padding: 0 24px; }

header {
  border-bottom: 1px solid var(--border);
  padding: 20px 0;
  background: var(--surface);
}

header .inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 16px;
}

header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

header .tagline {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-left: auto;
}

/* ── Form card ── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
}

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group.full { grid-column: 1 / -1; }

label {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

label .req { color: var(--accent); }

input, select, textarea {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-size: 0.95rem;
  padding: 10px 14px;
  transition: border-color 0.2s, box-shadow 0.2s;
  font-family: inherit;
  width: 100%;
}

input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(79,142,247,0.15);
}

select option { background: var(--surface2); }

.hint {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ── Button ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: opacity 0.2s, transform 0.1s;
}

.btn:active { transform: scale(0.98); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
  width: 100%;
  font-size: 1rem;
  padding: 14px;
}

.btn-primary:hover:not(:disabled) { opacity: 0.9; }

.btn-sm {
  padding: 6px 14px;
  font-size: 0.8rem;
  border-radius: 6px;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
}

.btn-sm:hover { border-color: var(--accent); color: var(--accent); }

/* ── Status ── */
#status {
  display: none;
  margin-top: 20px;
  padding: 16px 20px;
  border-radius: 8px;
  font-size: 0.9rem;
}

#status.loading {
  display: flex;
  align-items: center;
  gap: 12px;
  background: rgba(79,142,247,0.1);
  border: 1px solid rgba(79,142,247,0.3);
  color: var(--accent);
}

#status.error {
  display: block;
  background: rgba(248,113,113,0.1);
  border: 1px solid rgba(248,113,113,0.3);
  color: var(--error);
}

.spinner {
  width: 18px; height: 18px;
  border: 2px solid rgba(79,142,247,0.3);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  flex-shrink: 0;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* ── Steps ── */
.steps {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.step { padding: 2px 10px; border-radius: 12px; background: var(--surface2); }
.step.active { background: rgba(79,142,247,0.2); color: var(--accent); }
.step.done { background: rgba(62,207,142,0.15); color: var(--success); }

/* ── Result ── */
#result {
  display: none;
  margin-top: 24px;
}

.result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  flex-wrap: wrap;
  gap: 10px;
}

.result-actions { display: flex; gap: 8px; }

/* ── Brief content ── */
.brief-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px 40px;
  box-shadow: var(--shadow);
}

.brief-content h1 { font-size: 1.8rem; margin-bottom: 8px; color: var(--text); }
.brief-content h2 { font-size: 1.2rem; margin: 28px 0 10px; color: var(--accent); border-bottom: 1px solid var(--border); padding-bottom: 6px; }
.brief-content h3 { font-size: 1rem; margin: 18px 0 6px; color: var(--text); }
.brief-content p { margin-bottom: 12px; color: var(--text); }
.brief-content ul, .brief-content ol { margin: 8px 0 16px 20px; }
.brief-content li { margin-bottom: 6px; }
.brief-content strong { color: var(--text); }
.brief-content em { color: var(--text-muted); }
.brief-content hr { border: none; border-top: 1px solid var(--border); margin: 24px 0; }

.brief-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 0.9rem;
}

.brief-content th {
  background: var(--surface2);
  padding: 10px 14px;
  text-align: left;
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  border: 1px solid var(--border);
}

.brief-content td {
  padding: 10px 14px;
  border: 1px solid var(--border);
  vertical-align: top;
}

.brief-content tr:nth-child(even) td { background: rgba(255,255,255,0.02); }

/* ── Past briefs ── */
.briefs-section { margin-top: 40px; }
.briefs-section h2 { font-size: 1rem; font-weight: 600; color: var(--text-muted); margin-bottom: 16px; text-transform: uppercase; letter-spacing: 0.05em; }

.briefs-list { display: flex; flex-direction: column; gap: 10px; }

.brief-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: border-color 0.2s;
}

.brief-item:hover { border-color: var(--accent); }

.brief-item-info { display: flex; flex-direction: column; gap: 2px; }
.brief-item-title { font-weight: 600; }
.brief-item-meta { font-size: 0.8rem; color: var(--text-muted); }

/* ── Brief page ── */
.brief-page { padding: 40px 0; }
.back-link { display: inline-flex; align-items: center; gap: 6px; margin-bottom: 24px; color: var(--text-muted); font-size: 0.875rem; }
.back-link:hover { color: var(--accent); text-decoration: none; }

main { padding: 40px 0; }

/* ── .opt label helper ── */
.opt { color: var(--text-muted); font-weight: 400; }

/* ── Mode toggle ── */
.toggle-row {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.toggle-btn {
  padding: 7px 18px;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--surface2);
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}

.toggle-btn:hover { border-color: var(--accent); color: var(--accent); }

.toggle-btn.active {
  background: rgba(79,142,247,0.15);
  border-color: var(--accent);
  color: var(--accent);
}

/* ── Date range row ── */
.date-range-row {
  display: flex;
  align-items: flex-end;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 10px;
}

.date-range-arrow {
  color: var(--text-muted);
  padding-bottom: 10px;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.duration-display {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 0.95rem;
  color: var(--text-muted);
  min-width: 100px;
}

/* month-picker-wrap top margin */
#month-picker-wrap { margin-top: 10px; }

@media (max-width: 600px) {
  .form-grid { grid-template-columns: 1fr; }
  .brief-content { padding: 24px 20px; }
  header .tagline { display: none; }
  .date-range-row { flex-direction: column; }
  .date-range-arrow { display: none; }
}