:root {
  --ser-bg: #F4F5F7;
  --ser-surface: #FFFFFF;
  --ser-surface-strong: #EAECEF;
  --ser-ink: #1B1C1D;
  --ser-muted: #5B6168;
  --ser-line: rgba(27, 28, 29, 0.12);
  --ser-accent: #E81C24;
  --ser-accent-soft: rgba(232, 28, 36, 0.08);
  --ser-alert: #F04438;
  --ser-danger: #E81C24;
  --ser-danger-soft: rgba(232, 28, 36, 0.12);
  --ser-info-soft: rgba(27, 28, 29, 0.08);
  --ser-shadow: 0 4px 12px rgba(27, 28, 29, 0.08);
  --ser-radius: 8px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ser-ink);
  background: var(--ser-bg);
}

a {
  color: inherit;
}

.ser-app {
  max-width: 1440px;
  margin: 0 auto;
  padding: 28px;
}

.ser-banner {
  margin-bottom: 18px;
  padding: 14px 18px;
  border: 1px solid rgba(180, 83, 9, 0.22);
  border-radius: var(--ser-radius);
  background: var(--ser-surface);
  color: #7c3d12;
}

.ser-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(320px, 0.9fr);
  gap: 20px;
  margin-bottom: 22px;
}

.ser-hero-card,
.ser-card {
  background: var(--ser-surface);
  border: 1px solid var(--ser-line);
  border-radius: var(--ser-radius);
  box-shadow: var(--ser-shadow);
  backdrop-filter: blur(10px);
}

.ser-hero-card {
  padding: 26px;
  position: relative;
  overflow: hidden;
}

.ser-kicker {
  margin: 0 0 10px;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.76rem;
  color: var(--ser-accent);
  font-weight: 700;
}

.ser-title {
  margin: 0;
  
  font-size: clamp(2rem, 3vw, 3.35rem);
  line-height: 1.02;
}

.ser-intro {
  margin: 16px 0 0;
  max-width: 62ch;
  color: var(--ser-muted);
  line-height: 1.65;
}

.ser-chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.ser-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--ser-radius);
  background: var(--ser-surface);
  border: 1px solid var(--ser-line);
  font-size: 0.87rem;
}

.ser-hero-panel {
  display: grid;
  gap: 14px;
}

.ser-meta-stack {
  display: grid;
  gap: 12px;
}

.ser-meta {
  padding: 18px;
  border-radius: var(--ser-radius);
  background: var(--ser-surface);
  border: 1px solid var(--ser-line);
}

.ser-meta-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ser-muted);
}

.ser-meta-value {
  margin-top: 8px;
  font-size: 1.3rem;
  font-weight: 700;
}

.ser-layout {
  display: grid;
  grid-template-columns: minmax(320px, 380px) minmax(0, 1fr);
  gap: 22px;
}

.ser-side,
.ser-main {
  display: grid;
  gap: 22px;
}

.ser-card {
  padding: 24px;
}

.ser-card h2,
.ser-card h3 {
  margin-top: 0;
}

.ser-card-heading {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 18px;
}

.ser-card-heading p {
  margin: 6px 0 0;
  color: var(--ser-muted);
}

.ser-status {
  min-height: 24px;
}

.ser-status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--ser-radius);
  font-size: 0.86rem;
  font-weight: 600;
}

.ser-status-success {
  background: rgba(15, 118, 110, 0.12);
  color: #0f5f59;
}

.ser-status-error {
  background: rgba(185, 28, 28, 0.12);
  color: #8f1d1d;
}

.ser-status-info {
  background: rgba(15, 118, 110, 0.1);
  color: #0f5f59;
}

.ser-form {
  display: grid;
  gap: 16px;
}

.ser-field {
  display: grid;
  gap: 8px;
}

.ser-field label,
.ser-checkbox strong {
  font-size: 0.95rem;
  font-weight: 700;
}

.ser-field small,
.ser-checkbox span,
.ser-help,
.ser-preview-note,
.ser-empty {
  color: var(--ser-muted);
  line-height: 1.5;
}

.ser-input,
.ser-select {
  width: 100%;
  min-height: 46px;
  padding: 11px 14px;
  border-radius: var(--ser-radius);
  border: 1px solid rgba(62, 44, 24, 0.18);
  background: var(--ser-surface);
  color: var(--ser-ink);
  font: inherit;
}

.ser-checkbox {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  align-items: flex-start;
  padding: 14px;
  border: 1px solid var(--ser-line);
  border-radius: var(--ser-radius);
  background: var(--ser-surface);
}

.ser-checkbox input {
  inline-size: 18px;
  block-size: 18px;
  margin-top: 2px;
}

.ser-actions,
.ser-button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.ser-button {
  appearance: none;
  border: 1px solid transparent;
  border-radius: var(--ser-radius);
  padding: 11px 16px;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease, background-color 160ms ease;
}

.ser-button:hover {
  transform: translateY(-1px);
}

.ser-button:focus-visible,
.ser-input:focus-visible,
.ser-select:focus-visible,
.ser-checkbox input:focus-visible {
  outline: 2px solid var(--ser-accent);
  outline-offset: 2px;
}

.ser-button-primary {
  color: #FFFFFF;
  background: var(--ser-ink);
  box-shadow: 0 4px 6px rgba(27, 28, 29, 0.1);
}

.ser-button-secondary {
  color: var(--ser-ink);
  background: var(--ser-surface);
  border-color: var(--ser-line);
}

.ser-button-danger {
  color: #8f1d1d;
  background: var(--ser-danger-soft);
}

.ser-summary-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.ser-stat {
  padding: 18px;
  border-radius: var(--ser-radius);
  border: 1px solid var(--ser-line);
  background: var(--ser-surface);
}

.ser-stat-label {
  display: block;
  color: var(--ser-muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.ser-stat strong {
  display: block;
  margin-top: 10px;
  font-size: 2rem;
  line-height: 1;
}

.ser-preview-shell {
  min-height: 420px;
  padding: 14px;
  border-radius: var(--ser-radius);
  border: 1px dashed rgba(62, 44, 24, 0.22);
  background: var(--ser-surface);
}

.ser-preview-stage {
  min-height: 380px;
}

.ser-preview-toolbar {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  margin-bottom: 14px;
}

.ser-preview-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--ser-radius);
  background: var(--ser-surface);
  border: 1px solid var(--ser-line);
  font-size: 0.84rem;
  color: var(--ser-muted);
}

.ser-demo-preview {
  display: grid;
  gap: 18px;
}

.ser-demo-hero,
.ser-demo-card,
.ser-demo-footer {
  border: 1px solid var(--ser-line);
  border-radius: var(--ser-radius);
  background: var(--ser-surface);
}

.ser-demo-hero {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  padding: 20px;
  background: var(--ser-surface);
}

.ser-demo-kicker,
.ser-demo-card-label {
  margin: 0 0 8px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.74rem;
  color: var(--ser-muted);
  font-weight: 700;
}

.ser-demo-title {
  margin: 0;
  font-size: 1.7rem;
  
}

.ser-demo-copy,
.ser-demo-note,
.ser-demo-card p {
  margin: 10px 0 0;
  color: var(--ser-muted);
  line-height: 1.55;
}

.ser-demo-price {
  flex: 0 0 auto;
  padding: 12px 16px;
  border-radius: var(--ser-radius);
  background: var(--ser-surface);
  border: 1px solid var(--ser-line);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--ser-accent);
}

.ser-demo-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.ser-demo-card,
.ser-demo-footer {
  padding: 18px;
}

.ser-demo-card strong {
  display: block;
  font-size: 1.05rem;
}

.ser-demo-card .ser-button {
  margin-top: 14px;
}

.ser-demo-footer {
  display: grid;
  gap: 12px;
}

.ser-table-wrap {
  overflow-x: auto;
}

.ser-table {
  width: 100%;
  border-collapse: collapse;
}

.ser-table th,
.ser-table td {
  padding: 12px 10px;
  border-bottom: 1px solid rgba(62, 44, 24, 0.1);
  text-align: left;
  vertical-align: top;
}

.ser-table th {
  color: var(--ser-muted);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.ser-badge {
  display: inline-flex;
  align-items: center;
  border-radius: var(--ser-radius);
  padding: 6px 10px;
  font-size: 0.78rem;
  font-weight: 700;
}

.ser-badge-info {
  background: var(--ser-info-soft);
  color: #0f5f59;
}

.ser-badge-warning {
  background: rgba(180, 83, 9, 0.14);
  color: #8f4a0d;
}

.ser-badge-critical {
  background: var(--ser-danger-soft);
  color: #8f1d1d;
}

.ser-footnote {
  margin-top: 16px;
  color: var(--ser-muted);
  font-size: 0.9rem;
}

@media (max-width: 1100px) {
  .ser-hero,
  .ser-layout {
    grid-template-columns: 1fr;
  }

  .ser-summary-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .ser-demo-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .ser-app {
    padding: 16px;
  }

  .ser-card,
  .ser-hero-card {
    padding: 18px;
    border-radius: var(--ser-radius);
  }

  .ser-summary-grid {
    grid-template-columns: 1fr;
  }

  .ser-preview-toolbar,
  .ser-card-heading,
  .ser-demo-hero {
    flex-direction: column;
    align-items: stretch;
  }
}

/* ─── Mode Banner ─── */
.ser-mode-banner {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
  padding: 12px 18px;
  border-radius: var(--ser-radius);
  font-size: 0.9rem;
  font-weight: 600;
}

.ser-mode-banner-neutral {
  background: var(--ser-info-soft);
  color: var(--ser-muted);
  border: 1px solid var(--ser-line);
}

.ser-mode-banner-live {
  background: rgba(15, 118, 110, 0.1);
  color: #0f5f59;
  border: 1px solid rgba(15, 118, 110, 0.25);
}

.ser-mode-banner-demo {
  background: rgba(180, 83, 9, 0.1);
  color: #8f4a0d;
  border: 1px solid rgba(180, 83, 9, 0.25);
}

.ser-mode-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.ser-mode-banner-neutral .ser-mode-dot {
  background: var(--ser-muted);
}

.ser-mode-banner-live .ser-mode-dot {
  background: #0f766e;
  box-shadow: 0 0 6px rgba(15, 118, 110, 0.45);
  animation: ser-pulse 2s ease-in-out infinite;
}

.ser-mode-banner-demo .ser-mode-dot {
  background: #b45309;
}

@keyframes ser-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.ser-button-link {
  appearance: none;
  background: none;
  border: none;
  padding: 0;
  margin-left: auto;
  font: inherit;
  font-size: 0.86rem;
  font-weight: 700;
  color: inherit;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.ser-button-link:hover {
  opacity: 0.7;
}

/* ─── Data Source Badge ─── */
.ser-data-badge {
  display: inline-flex;
  align-items: center;
  vertical-align: middle;
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 0.65rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-left: 8px;
}

.ser-data-badge-live {
  background: rgba(15, 118, 110, 0.14);
  color: #0f5f59;
}

.ser-data-badge-demo {
  background: rgba(180, 83, 9, 0.14);
  color: #8f4a0d;
}

/* ─── Onboarding Guide ─── */
.ser-onboarding {
  margin-bottom: 18px;
}

.ser-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-bottom: 18px;
}

.ser-step {
  display: flex;
  gap: 14px;
  padding: 18px;
  border-radius: var(--ser-radius);
  border: 1px solid var(--ser-line);
  background: var(--ser-surface);
}

.ser-step-number {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--ser-ink);
  color: #FFFFFF;
  font-size: 1rem;
  font-weight: 800;
}

.ser-step strong {
  display: block;
  margin-bottom: 6px;
}

.ser-step p {
  margin: 0;
  color: var(--ser-muted);
  line-height: 1.5;
  font-size: 0.9rem;
}

.ser-onboarding-tips {
  padding: 14px 18px;
  border-radius: var(--ser-radius);
  background: var(--ser-info-soft);
  display: grid;
  gap: 4px;
}

.ser-onboarding-tips p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--ser-muted);
  line-height: 1.5;
}

.ser-button-sm {
  padding: 7px 12px;
  font-size: 0.84rem;
}

/* ─── Session History ─── */
#session-history-card {
  margin-bottom: 18px;
}

.ser-history-list {
  display: grid;
  gap: 12px;
}

.ser-history-entry {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 14px;
  align-items: center;
  padding: 16px;
  border-radius: var(--ser-radius);
  border: 1px solid var(--ser-line);
  background: var(--ser-surface);
}

.ser-history-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  font-size: 0.88rem;
}

.ser-history-date {
  font-weight: 700;
}

.ser-history-mode {
  display: inline-flex;
  padding: 2px 7px;
  border-radius: 4px;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.ser-history-mode-live {
  background: rgba(15, 118, 110, 0.14);
  color: #0f5f59;
}

.ser-history-mode-demo {
  background: rgba(180, 83, 9, 0.14);
  color: #8f4a0d;
}

.ser-history-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 6px;
  font-size: 0.84rem;
  color: var(--ser-muted);
}

.ser-history-stats strong {
  color: var(--ser-ink);
}

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

/* ─── Empty State ─── */
.ser-empty-state {
  text-align: center;
  padding: 28px 18px;
  color: var(--ser-muted);
}

.ser-empty-state-icon {
  font-size: 2rem;
  margin: 0 0 6px;
}

.ser-empty-state p {
  margin: 4px 0;
  line-height: 1.5;
}

.ser-empty-state strong {
  color: var(--ser-ink);
}

@media (max-width: 1100px) {
  .ser-steps {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .ser-steps {
    grid-template-columns: 1fr;
  }

  .ser-history-entry {
    grid-template-columns: 1fr;
  }
}