/* ── Variables ── */
:root {
  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --primary-light: #eef2ff;
  --danger: #dc2626;
  --danger-light: #fef2f2;
  --success: #16a34a;
  --success-light: #f0fdf4;
  --warning: #d97706;
  --bg: #f8fafc;
  --surface: #ffffff;
  --border: #e2e8f0;
  --text: #1e293b;
  --text-muted: #64748b;
  --radius: 6px;
  --radius-lg: 12px;
  --shadow: 0 1px 3px rgb(0 0 0 / 12%), 0 1px 2px rgb(0 0 0 / 8%);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 10%), 0 4px 6px -4px rgb(0 0 0 / 10%);
  --header-h: 56px;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: system-ui, -apple-system, sans-serif; background: var(--bg); color: var(--text); line-height: 1.5; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
input, textarea, select { font-family: inherit; }

/* ── Layout ── */
#app { min-height: 100vh; display: flex; flex-direction: column; }
.main-content { flex: 1; padding: 2rem; max-width: 1100px; margin: 0 auto; width: 100%; }

/* ── Header ── */
.app-header {
  height: var(--header-h); background: var(--primary); color: #fff;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 1.5rem; position: sticky; top: 0; z-index: 50;
}
.header-brand { display: flex; align-items: center; gap: 0.5rem; font-weight: 700; font-size: 1.1rem; }
.header-logo { font-size: 1.4rem; }
.header-nav { display: flex; align-items: center; gap: 1rem; }
.nav-link { opacity: 0.85; transition: opacity 0.15s; }
.nav-link:hover { opacity: 1; }

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; gap: 0.35rem;
  padding: 0.45rem 1rem; border: none; border-radius: var(--radius);
  font-size: 0.875rem; font-weight: 600; line-height: 1; transition: filter 0.15s;
}
.btn:hover { filter: brightness(0.92); }
.btn:disabled { opacity: 0.55; cursor: not-allowed; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-danger  { background: var(--danger);  color: #fff; }
.btn-outline { background: transparent; border: 1.5px solid rgba(255,255,255,0.6); color: #fff; }
.btn-ghost   { background: transparent; border: 1.5px solid var(--border); color: var(--text); }
.btn-sm      { padding: 0.3rem 0.7rem; font-size: 0.8rem; }
.btn-full    { width: 100%; justify-content: center; padding: 0.6rem; }

/* ── Forms ── */
.form-group { margin-bottom: 1.1rem; }
.form-label { display: block; font-size: 0.85rem; font-weight: 600; margin-bottom: 0.3rem; color: var(--text); }
.form-label.required::after { content: ' *'; color: var(--danger); }
.form-control {
  width: 100%; padding: 0.5rem 0.75rem; font-size: 0.9rem;
  border: 1.5px solid var(--border); border-radius: var(--radius);
  background: var(--surface); color: var(--text); transition: border-color 0.15s;
}
.form-control:focus { outline: none; border-color: var(--primary); }
.form-control[type="textarea"], textarea.form-control { min-height: 80px; resize: vertical; font-family: monospace; font-size: 0.82rem; }
.field-hint { font-size: 0.78rem; color: var(--text-muted); margin-top: 0.25rem; }
.field-type { font-size: 0.7rem; font-weight: 400; color: var(--text-muted); margin-left: 0.4rem; background: var(--bg); padding: 0.1rem 0.35rem; border-radius: 99px; }

/* ── Alerts ── */
.alert { padding: 0.65rem 0.9rem; border-radius: var(--radius); font-size: 0.875rem; margin-bottom: 1rem; }
.alert-error   { background: var(--danger-light);  color: var(--danger);  border: 1px solid #fecaca; }
.alert-success { background: var(--success-light); color: var(--success); border: 1px solid #bbf7d0; }
.hidden { display: none !important; }

/* ── Login Page ── */
.login-page { display: flex; align-items: center; justify-content: center; min-height: 100vh; background: var(--bg); }
.login-card { background: var(--surface); padding: 2.5rem; border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); width: 100%; max-width: 400px; }
.login-title { font-size: 1.5rem; font-weight: 700; margin-bottom: 0.25rem; color: var(--text); }
.login-subtitle { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 1.75rem; }

/* ── Page toolbar ── */
.page-toolbar { display: flex; align-items: center; gap: 1rem; margin-bottom: 1.5rem; }
.search-input { flex: 1; padding: 0.5rem 0.75rem; border: 1.5px solid var(--border); border-radius: var(--radius); font-size: 0.9rem; background: var(--surface); }
.search-input:focus { outline: none; border-color: var(--primary); }

/* ── Flows Grid ── */
.flows-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1rem; }
.flow-card {
  background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.25rem; display: flex; flex-direction: column; gap: 0.5rem;
  box-shadow: var(--shadow); transition: box-shadow 0.15s, border-color 0.15s;
}
.flow-card:hover { box-shadow: var(--shadow-lg); border-color: #c7d2fe; }
.flow-card-header { display: flex; flex-direction: column; gap: 0.2rem; }
.flow-card-name { font-weight: 700; font-size: 1rem; }
.flow-card-id { font-size: 0.75rem; color: var(--text-muted); font-family: monospace; }
.flow-card-desc { font-size: 0.85rem; color: var(--text-muted); flex: 1; }
.flow-card-actions { display: flex; gap: 0.5rem; margin-top: 0.5rem; }

/* ── Loading / Empty states ── */
.loading { text-align: center; padding: 3rem; color: var(--text-muted); }
.empty-state { text-align: center; padding: 3rem; color: var(--text-muted); font-size: 0.9rem; }



/* ── Flow Detail Page ── */
.flow-detail-header {
  display: flex; align-items: flex-start; justify-content: space-between;
  gap: 1rem; margin-bottom: 2rem; flex-wrap: wrap;
}
.flow-detail-meta h1 { font-size: 1.6rem; font-weight: 700; margin-bottom: 0.2rem; }
.flow-detail-meta p  { color: var(--text-muted); font-size: 0.9rem; }
.flow-detail-actions { display: flex; gap: 0.5rem; flex-shrink: 0; }
.back-link { display: inline-flex; align-items: center; gap: 0.3rem; color: var(--text-muted); font-size: 0.875rem; margin-bottom: 1rem; }
.back-link:hover { color: var(--primary); }

/* ── Chain Visualization ── */
.chain-container { display: flex; flex-direction: column; align-items: center; gap: 0; }
.chain-step { display: flex; flex-direction: column; align-items: center; width: 100%; max-width: 560px; }
.chain-connector { width: 2px; height: 24px; background: var(--border); flex-shrink: 0; }

/* ── Operation Node Block ── */
.op-block {
  width: 100%; background: var(--surface); border: 2px solid var(--border);
  border-radius: var(--radius-lg); padding: 0.9rem 1.1rem;
  cursor: pointer; transition: border-color 0.15s, box-shadow 0.15s;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
}
.op-block:hover { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-light); }
.op-block.selected { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-light); }
.op-block-left { display: flex; flex-direction: column; gap: 0.2rem; overflow: hidden; }
.op-key { font-family: monospace; font-size: 0.82rem; color: var(--text-muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.op-label { font-weight: 600; font-size: 0.9rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.op-badge {
  flex-shrink: 0; font-size: 0.7rem; font-weight: 700; padding: 0.2rem 0.55rem;
  border-radius: 99px; text-transform: uppercase; letter-spacing: 0.04em; color: #fff;
}
.badge-transform_data        { background: #3b82f6; }
.badge-check_data            { background: #f59e0b; }
.badge-for_each_item         { background: #8b5cf6; }
.badge-respond_with_success  { background: #22c55e; }
.badge-respond_with_error    { background: #ef4444; }
.badge-send_to_url           { background: #06b6d4; }
.badge-log_data              { background: #94a3b8; }
.badge-return_data_to_iterator   { background: #6366f1; }
.badge-return_error_to_iterator  { background: #f43f5e; }
.badge-start                 { background: #475569; }

/* ── Branches ── */
.branch-row { display: flex; gap: 0; width: 100%; justify-content: center; }
.branch-col { display: flex; flex-direction: column; align-items: center; flex: 1; min-width: 0; max-width: 300px; }
.branch-label {
  font-size: 0.75rem; font-weight: 700; padding: 0.2rem 0.7rem;
  border-radius: 99px; text-transform: uppercase; letter-spacing: 0.05em; white-space: nowrap;
}
.branch-label.success { background: var(--success-light); color: var(--success); }
.branch-label.failure { background: var(--danger-light);  color: var(--danger);  }
.branch-line { width: 2px; height: 16px; }
.branch-line.success { background: var(--success); }
.branch-line.failure { background: var(--danger); }
.branch-divider { width: 1px; background: var(--border); align-self: stretch; margin: 0 0.5rem; }
.iterator-wrap { width: 100%; border: 1.5px dashed var(--border); border-radius: var(--radius-lg); padding: 1rem; }
.iterator-label { font-size: 0.75rem; color: var(--text-muted); font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 0.75rem; text-align: center; }
.chain-add-row { display: flex; justify-content: center; margin-top: 1.5rem; }

/* ── Node Detail Modal ── */
.modal-overlay {
  position: fixed; inset: 0; background: rgb(0 0 0 / 45%);
  display: flex; align-items: center; justify-content: center; z-index: 200; padding: 1rem;
}
.modal {
  background: var(--surface); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg); width: 100%; max-width: 600px;
  max-height: 85vh; display: flex; flex-direction: column;
}
.modal-header {
  padding: 1.1rem 1.25rem; border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-shrink: 0;
}
.modal-title { font-weight: 700; font-size: 1rem; display: flex; align-items: center; gap: 0.5rem; }
.modal-close { background: none; border: none; font-size: 1.4rem; line-height: 1; color: var(--text-muted); padding: 0.25rem; border-radius: var(--radius); }
.modal-close:hover { background: var(--bg); }
.modal-body { padding: 1.25rem; overflow-y: auto; flex: 1; }
.modal-footer { padding: 1rem 1.25rem; border-top: 1px solid var(--border); display: flex; gap: 0.5rem; justify-content: flex-end; flex-shrink: 0; }
.node-detail-field { margin-bottom: 0.75rem; }
.node-field-name { font-size: 0.78rem; font-weight: 600; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 0.2rem; }
.node-field-value { font-size: 0.875rem; color: var(--text); word-break: break-all; }
.node-field-value.mono { font-family: monospace; background: var(--bg); padding: 0.3rem 0.5rem; border-radius: var(--radius); white-space: pre-wrap; font-size: 0.8rem; }
.modal-subtitle { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 1.25rem; }