.beihang-core {
  --ui-ink: #090a0c;
  --ui-paper: #f4f3ef;
  --ui-aluminum: #c9c8c3;
  --ui-muted: #6b6d72;
  --ui-safety: #f05a1a;
  --ui-line: rgba(9, 10, 12, 0.16);
  color: var(--ui-ink);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  line-height: 1.55;
}

.beihang-core *,
.beihang-core *::before,
.beihang-core *::after {
  box-sizing: border-box;
}

.beihang-core [hidden] {
  display: none !important;
}

.beihang-core a {
  color: inherit;
  text-decoration: none;
}

.beihang-core h1,
.beihang-core h2,
.beihang-core h3,
.beihang-core p {
  margin-top: 0;
}

.beihang-core h1 {
  max-width: 16ch;
  margin-bottom: 24px;
  font-size: clamp(2.6rem, 6vw, 5.6rem);
  font-weight: 650;
  letter-spacing: -0.055em;
  line-height: 0.98;
}

.beihang-core h2 {
  margin-bottom: 20px;
  font-size: clamp(1.55rem, 3vw, 2.1rem);
  font-weight: 650;
  letter-spacing: -0.025em;
  line-height: 1.12;
}

.beihang-core h3 {
  margin: 28px 0 14px;
  font-size: 1rem;
  font-weight: 700;
}

.beihang-container {
  width: min(1180px, calc(100% - 40px));
  margin-inline: auto;
}

.beihang-kicker {
  margin-bottom: 14px;
  color: var(--ui-safety);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  line-height: 1.4;
  text-transform: uppercase;
}

.beihang-page-intro {
  overflow: hidden;
  border-bottom: 1px solid var(--ui-line);
  background: var(--ui-paper);
  padding: 28px 0;
}

.beihang-page-intro__frame {
  display: grid;
  overflow: hidden;
  min-height: 512px;
  border: 1px solid var(--ui-line);
  background: #fff;
  grid-template-columns: minmax(0, 0.86fr) minmax(320px, 1.14fr);
}

.beihang-page-intro__copy-panel {
  position: relative;
  display: flex;
  min-width: 0;
  flex-direction: column;
  justify-content: space-between;
  overflow: hidden;
  border-right: 1px solid var(--ui-line);
  padding: clamp(28px, 4vw, 44px);
  background-color: #fff;
  background-image:
    linear-gradient(rgba(9, 10, 12, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(9, 10, 12, 0.055) 1px, transparent 1px);
  background-size: 72px 72px;
}

.beihang-page-intro__copy {
  max-width: 690px;
  margin-bottom: 30px;
  color: var(--ui-muted);
  font-size: 1.02rem;
  line-height: 1.85;
}

.beihang-page-intro__meta {
  display: flex;
  flex-wrap: wrap;
  border-top: 1px solid var(--ui-line);
  border-left: 1px solid var(--ui-line);
}

.beihang-page-intro__meta span {
  min-width: 150px;
  flex: 1 1 0;
  border-right: 1px solid var(--ui-line);
  border-bottom: 1px solid var(--ui-line);
  padding: 16px;
  font-size: 0.78rem;
  font-weight: 700;
}

.beihang-page-intro__meta b {
  display: block;
  margin-bottom: 4px;
  color: var(--ui-safety);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.66rem;
}

.beihang-page-intro__visual {
  position: relative;
  overflow: hidden;
  min-height: 304px;
  margin: 0;
  background: var(--ui-ink);
  color: #fff;
}

.beihang-page-intro__visual > img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 650ms cubic-bezier(0.16, 1, 0.3, 1);
}

.beihang-page-intro__visual:hover > img {
  transform: scale(1.018);
}

.beihang-photo-label,
.beihang-page-intro__visual figcaption {
  position: absolute;
  z-index: 2;
  right: 0;
  left: 0;
  border-color: rgba(255, 255, 255, 0.25);
  background: rgba(0, 0, 0, 0.65);
  color: #fff;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.64rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.beihang-photo-label {
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid rgba(255, 255, 255, 0.25);
  padding: 16px 20px;
}

.beihang-photo-label strong {
  color: var(--ui-safety);
}

.beihang-page-intro__visual figcaption {
  bottom: 0;
  margin: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.25);
  padding: 16px 20px;
  background: rgba(0, 0, 0, 0.75);
  line-height: 1.6;
}

.beihang-cart-page .beihang-page-intro,
.beihang-search-page .beihang-page-intro,
.beihang-received-page .beihang-page-intro {
  padding: clamp(64px, 8vw, 96px) 0;
}

.beihang-aluminum-section {
  background: var(--ui-aluminum);
  padding: clamp(60px, 8vw, 96px) 0;
}

.beihang-rfq-layout {
  display: grid;
  align-items: start;
  gap: 28px;
  grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
}

.beihang-panel,
.beihang-rfq-card {
  border: 1px solid var(--ui-line);
  background: #fff;
  box-shadow: 0 16px 38px rgba(9, 10, 12, 0.07);
}

.beihang-panel {
  padding: clamp(24px, 4vw, 32px);
}

.beihang-panel > p:not(.beihang-kicker),
.beihang-rfq-complete > p:not(.beihang-kicker) {
  color: var(--ui-muted);
  font-size: 0.9rem;
  line-height: 1.85;
}

.beihang-number-list {
  margin: 0;
  border-top: 1px solid var(--ui-line);
  padding: 0;
  list-style: none;
}

.beihang-number-list li {
  display: grid;
  border-bottom: 1px solid var(--ui-line);
  padding: 14px 0;
  color: var(--ui-muted);
  font-size: 0.84rem;
  grid-template-columns: 38px 1fr;
}

.beihang-number-list span,
.beihang-assurance-grid b,
.beihang-process__steps b {
  color: var(--ui-safety);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.68rem;
}

.beihang-note {
  margin: 22px 0 0;
  border-left: 2px solid var(--ui-safety);
  background: var(--ui-paper);
  padding: 14px 16px;
  color: var(--ui-muted);
  font-size: 0.76rem;
  line-height: 1.7;
}

.beihang-assurance-grid {
  display: grid;
  border-top: 1px solid var(--ui-line);
  border-left: 1px solid var(--ui-line);
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.beihang-assurance-grid span {
  display: grid;
  min-height: 58px;
  align-items: center;
  border-right: 1px solid var(--ui-line);
  border-bottom: 1px solid var(--ui-line);
  padding: 10px 12px;
  font-size: 0.72rem;
  font-weight: 650;
  grid-template-columns: 24px 1fr;
}

.beihang-rfq-progress {
  display: grid;
  margin: 0;
  border-bottom: 1px solid var(--ui-line);
  padding: 0;
  list-style: none;
  grid-template-columns: repeat(3, 1fr);
}

.beihang-rfq-progress li {
  min-width: 0;
  border-right: 1px solid var(--ui-line);
  background: #fff;
  padding: 17px 18px;
}

.beihang-rfq-progress li:last-child {
  border-right: 0;
}

.beihang-rfq-progress li[aria-current='step'] {
  background: var(--ui-ink);
  color: #fff;
}

.beihang-rfq-progress span {
  display: block;
  margin-bottom: 4px;
  color: var(--ui-muted);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.62rem;
}

.beihang-rfq-progress .is-complete span {
  color: var(--ui-safety);
}

.beihang-rfq-progress li[aria-current='step'] span {
  color: rgba(255, 255, 255, 0.7);
}

.beihang-rfq-progress strong {
  display: block;
  overflow: hidden;
  font-size: 0.78rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.beihang-rfq-form,
.beihang-rfq-complete {
  padding: clamp(22px, 4vw, 30px);
}

.beihang-rfq-step:focus {
  outline: none;
}

.beihang-family-grid {
  display: grid;
  gap: 8px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.beihang-family-grid button {
  min-height: 96px;
  border: 1px solid var(--ui-line);
  border-radius: 0;
  background: #fff;
  color: var(--ui-ink);
  padding: 15px;
  text-align: left;
  transition: border-color 150ms ease, background-color 150ms ease;
}

.beihang-family-grid button:hover,
.beihang-family-grid button:focus-visible,
.beihang-family-grid button[aria-pressed='true'] {
  border-color: var(--ui-safety);
  background: var(--ui-paper);
  outline: none;
}

.beihang-family-grid strong,
.beihang-family-grid span {
  display: block;
}

.beihang-family-grid strong {
  margin-bottom: 8px;
  font-size: 0.83rem;
}

.beihang-family-grid span {
  color: var(--ui-muted);
  font-size: 0.7rem;
  line-height: 1.55;
}

.beihang-mode-list {
  display: grid;
  gap: 8px;
  margin: 24px 0 0;
  border: 0;
  padding: 0;
}

.beihang-mode-list legend {
  margin-bottom: 10px;
  font-size: 0.82rem;
  font-weight: 700;
}

.beihang-mode-list label {
  display: grid;
  cursor: pointer;
  border: 1px solid var(--ui-line);
  padding: 12px 14px;
  grid-template-columns: 20px 1fr;
}

.beihang-mode-list input {
  margin-top: 4px;
  accent-color: var(--ui-safety);
}

.beihang-mode-list strong,
.beihang-mode-list small {
  display: block;
}

.beihang-mode-list strong {
  font-size: 0.8rem;
}

.beihang-mode-list small {
  margin-top: 3px;
  color: var(--ui-muted);
  font-size: 0.68rem;
}

.beihang-field-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.beihang-field {
  display: grid;
  gap: 7px;
  min-width: 0;
  color: var(--ui-ink);
  font-size: 0.78rem;
  font-weight: 650;
}

.beihang-field--wide {
  grid-column: 1 / -1;
}

.beihang-field input:not([type='file']),
.beihang-field textarea,
.beihang-search-form input {
  width: 100%;
  min-height: 48px;
  border: 1px solid rgba(9, 10, 12, 0.2);
  border-radius: 0;
  background: #fff;
  color: var(--ui-ink);
  padding: 11px 14px;
  font: inherit;
  font-size: 0.82rem;
  font-weight: 400;
  outline: none;
  transition: border-color 150ms ease, box-shadow 150ms ease;
}

.beihang-field textarea {
  resize: vertical;
}

.beihang-field input:focus,
.beihang-field textarea:focus,
.beihang-search-form input:focus {
  border-color: var(--ui-safety);
  box-shadow: 0 0 0 1px var(--ui-safety);
}

.beihang-rfq-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: 26px;
  border-top: 1px solid var(--ui-line);
  padding-top: 20px;
}

.beihang-button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--ui-ink);
  border-radius: 0;
  background: var(--ui-ink);
  color: #fff !important;
  cursor: pointer;
  padding: 11px 20px;
  font-size: 0.8rem;
  font-weight: 700;
  line-height: 1.2;
  text-align: center;
  transition: border-color 150ms ease, background-color 150ms ease, color 150ms ease;
}

.beihang-button:hover,
.beihang-button:focus-visible {
  border-color: var(--ui-safety);
  background: var(--ui-safety);
  outline: none;
}

.beihang-button--secondary {
  border-color: rgba(9, 10, 12, 0.2);
  background: #fff;
  color: var(--ui-ink) !important;
}

.beihang-button--secondary:hover,
.beihang-button--secondary:focus-visible {
  border-color: var(--ui-safety);
  background: #fff;
  color: var(--ui-safety) !important;
}

.beihang-button--wide {
  width: 100%;
}

.beihang-button:disabled {
  cursor: wait;
  opacity: 0.58;
}

.beihang-feedback {
  margin: 18px 0 0;
  border-left: 2px solid;
  padding: 13px 15px;
  font-size: 0.8rem;
}

.beihang-feedback--error {
  border-color: #b42318;
  background: #fff2f0;
  color: #8a1c13;
}

.beihang-feedback--success {
  border-color: var(--ui-safety);
  background: var(--ui-paper);
  color: var(--ui-ink);
}

.beihang-stack-actions {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

.beihang-upload-form {
  min-width: 0;
}

.beihang-upload-picker {
  margin-top: 18px;
}

.beihang-upload-picker input[type='file'] {
  min-height: 52px;
  border: 1px solid rgba(9, 10, 12, 0.2);
  background: #fff;
  padding: 10px;
  font-size: 0.76rem;
}

.beihang-upload-picker input[type='file']::file-selector-button {
  margin-right: 14px;
  border: 0;
  background: var(--ui-ink);
  color: #fff;
  padding: 9px 13px;
  font-weight: 700;
}

.beihang-file-list {
  margin: 10px 0 18px;
  border: 1px solid var(--ui-line);
  background: var(--ui-paper);
  padding: 12px 14px;
  color: var(--ui-muted);
  font-size: 0.72rem;
}

.beihang-file-list__title {
  margin-bottom: 8px;
  color: var(--ui-ink);
  font-weight: 700;
}

.beihang-file-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-top: 1px solid var(--ui-line);
  background: #fff;
  padding: 9px;
}

.beihang-file-row span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.beihang-file-row button,
.beihang-cart-line__remove,
.beihang-cart-clear {
  border: 0;
  background: transparent;
  color: var(--ui-muted);
  cursor: pointer;
  font-size: 0.72rem;
  font-weight: 700;
}

.beihang-process {
  margin-bottom: 24px;
}

.beihang-process__steps {
  display: grid;
  margin-top: 18px;
  border-top: 1px solid var(--ui-line);
  border-left: 1px solid var(--ui-line);
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.beihang-process__steps span {
  display: grid;
  min-height: 76px;
  align-content: center;
  border-right: 1px solid var(--ui-line);
  border-bottom: 1px solid var(--ui-line);
  background: var(--ui-paper);
  padding: 14px;
  font-size: 0.76rem;
  font-weight: 700;
}

.beihang-process__steps b {
  display: block;
  margin-bottom: 5px;
}

.beihang-cart-layout {
  display: grid;
  align-items: start;
  gap: 24px;
  grid-template-columns: minmax(0, 1fr) 352px;
}

.beihang-cart-lines {
  display: grid;
  gap: 14px;
}

.beihang-cart-line {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  border: 1px solid var(--ui-line);
  background: #fff;
  padding: 20px;
}

.beihang-cart-line__title {
  font-size: 1.05rem;
  font-weight: 700;
}

.beihang-cart-line p {
  margin: 8px 0;
  color: var(--ui-muted);
  font-size: 0.78rem;
}

.beihang-cart-quantity {
  display: grid;
  align-items: center;
  grid-template-columns: repeat(3, 40px);
}

.beihang-cart-quantity button,
.beihang-cart-quantity span {
  display: grid;
  width: 40px;
  height: 40px;
  place-items: center;
  border: 1px solid var(--ui-line);
  background: #fff;
  color: var(--ui-ink);
}

.beihang-cart-quantity button {
  cursor: pointer;
}

.beihang-cart-summary {
  position: sticky;
  top: 110px;
}

.beihang-cart-count {
  margin-bottom: 8px;
  color: var(--ui-ink) !important;
  font-size: 2rem !important;
  font-weight: 700;
}

.beihang-cart-summary form {
  display: grid;
  gap: 11px;
  margin-top: 20px;
}

.beihang-cart-summary > .beihang-button {
  margin-top: 12px;
}

.beihang-cart-clear {
  display: block;
  width: 100%;
  margin-top: 12px;
  padding: 10px;
}

.beihang-cart-empty h2,
.beihang-search-empty h2 {
  margin-bottom: 10px;
}

.beihang-cart-empty .beihang-button,
.beihang-search-empty .beihang-button {
  margin-top: 12px;
}

.beihang-search-form {
  border: 1px solid var(--ui-line);
  background: #fff;
  padding: 22px;
}

.beihang-search-form > label {
  display: block;
  margin-bottom: 9px;
  font-size: 0.8rem;
  font-weight: 700;
}

.beihang-search-form > div {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
}

.beihang-search-form input {
  border-right: 0;
}

.beihang-search-count {
  margin: 22px 0;
  color: var(--ui-muted);
  font-size: 0.85rem;
}

.beihang-search-results {
  display: grid;
  gap: 14px;
}

.beihang-cisco-results {
  margin-bottom: 32px;
}

.beihang-search-section-title {
  border-bottom: 1px solid var(--ui-line);
  padding: 14px 0;
}

.beihang-search-section-title h2 {
  margin-bottom: 0;
  font-size: 1.25rem;
}

.beihang-cisco-row {
  display: grid;
  align-items: center;
  gap: 18px;
  border-right: 1px solid var(--ui-line);
  border-bottom: 1px solid var(--ui-line);
  border-left: 1px solid var(--ui-line);
  background: #fff;
  padding: 18px 20px;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr) auto;
}

.beihang-cisco-row strong,
.beihang-cisco-row span,
.beihang-cisco-row small {
  display: block;
}

.beihang-cisco-row strong {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.85rem;
}

.beihang-cisco-row span {
  color: var(--ui-muted);
  font-size: 0.8rem;
}

.beihang-cisco-row small {
  margin-top: 4px;
  color: var(--ui-safety);
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.beihang-cisco-row > div:last-child {
  display: flex;
  gap: 8px;
}

.beihang-cisco-row .beihang-button {
  min-height: 40px;
  padding: 8px 13px;
  font-size: 0.7rem;
}

.beihang-product-card {
  display: grid;
  gap: 20px;
  border: 1px solid var(--ui-line);
  background: #fff;
  padding: 20px;
  grid-template-columns: 150px minmax(0, 1fr);
}

.beihang-product-card img {
  width: 150px;
  height: 130px;
  object-fit: contain;
}

.beihang-product-card h2 {
  margin-bottom: 10px;
  font-size: 1.2rem;
}

.beihang-product-card p:not(.beihang-kicker) {
  margin-bottom: 8px;
  color: var(--ui-muted);
  font-size: 0.78rem;
}

.beihang-product-card__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.beihang-search-empty {
  margin-top: 20px;
}

.beihang-received-card {
  max-width: 760px;
  margin-inline: auto;
  text-align: center;
}

.beihang-received-card h2 {
  overflow-wrap: anywhere;
}

.beihang-received-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 26px;
}

@media (max-width: 900px) {
  .beihang-page-intro__frame,
  .beihang-rfq-layout,
  .beihang-cart-layout {
    grid-template-columns: 1fr;
  }

  .beihang-page-intro__copy-panel {
    border-right: 0;
    border-bottom: 1px solid var(--ui-line);
  }

  .beihang-cisco-row {
    grid-template-columns: 1fr;
  }

  .beihang-page-intro__visual {
    min-height: 320px;
  }

  .beihang-cart-summary {
    position: static;
  }

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

@media (max-width: 620px) {
  .beihang-container {
    width: min(100% - 24px, 1180px);
  }

  .beihang-aluminum-section {
    padding: 52px 0;
  }

  .beihang-page-intro {
    padding: 20px 0;
  }

  .beihang-core h1 {
    font-size: 2.55rem;
  }

  .beihang-page-intro__visual {
    min-height: 270px;
  }

  .beihang-family-grid,
  .beihang-field-grid,
  .beihang-assurance-grid,
  .beihang-process__steps {
    grid-template-columns: 1fr;
  }

  .beihang-rfq-progress li {
    padding: 13px 9px;
  }

  .beihang-rfq-progress strong {
    font-size: 0.66rem;
  }

  .beihang-cart-line {
    display: grid;
  }

  .beihang-product-card {
    grid-template-columns: 1fr;
  }

  .beihang-product-card img {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .beihang-core *,
  .beihang-core *::before,
  .beihang-core *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}