/* Bingo Tech — www.bingoai.ai (layout aligned with www.bingoai.cn) */

:root {
  --container-width: 1000px;
  --color-primary: #041128;
  --color-text: #333;
  --color-muted: #4f4f4f;
  --color-border: rgba(0, 0, 0, 0.1);
  --color-divider: rgba(0, 0, 0, 0.3);
  --font-sans: "PingFang SC", "Helvetica Neue", Helvetica, "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  color: var(--color-text);
  line-height: 1.6;
  background: #fff;
}

a {
  color: inherit;
  text-decoration: none;
}

a:hover {
  color: var(--color-primary);
}

.container {
  width: 100%;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: 20px;
}

/* ========== Header (aligned with bingoai.cn) ========== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: 20px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--color-primary);
  font-weight: 600;
  font-size: 18px;
}

.logo:hover {
  color: var(--color-primary);
}

.logo img {
  width: 32px;
  height: 32px;
  border-radius: 6px;
}

.nav {
  display: flex;
  gap: 32px;
}

.nav a {
  color: var(--color-muted);
  font-weight: 500;
  font-size: 15px;
}

.nav a:hover,
.nav a.active {
  color: var(--color-text);
}

.nav a.active {
  font-weight: 600;
}

.menu-btn {
  display: none;
  flex-direction: column;
  gap: 6px;
  background: none;
  border: none;
  color: var(--color-text);
  cursor: pointer;
  padding: 8px;
}

.menu-btn span {
  width: 24px;
  height: 2px;
  background: currentColor;
  border-radius: 1px;
}

@media (max-width: 768px) {
  .nav {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: 20px;
    gap: 16px;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.25s, opacity 0.25s, visibility 0.25s;
  }

  .nav.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .menu-btn {
    display: flex;
  }
}

/* ========== Banner — same structure as bingoai.cn .bg-color-box ========== */
@media screen and (min-width: 769px) {
  .bg-color-box {
    width: 100%;
    height: 620px;
    padding-top: 80px;
    padding-bottom: 30px;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(180deg, #f8f9fc 0%, #fff 100%);
  }

  .bg-color-box .banner-title-box {
    width: var(--container-width);
    max-width: 100%;
    height: calc(100% - 56px);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-inline: 20px;
  }

  .bg-color-box .banner-title-box .banner-title {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
  }

  .bg-color-box .banner-title-box .banner-title .banner-title-weight {
    font-family: var(--font-sans);
    font-weight: 500;
    font-size: 50px;
    margin: 0 0 16px;
    color: var(--color-primary);
    line-height: 1.2;
    letter-spacing: -0.02em;
  }

  .bg-color-box .banner-title-box .banner-title .banner-title-item {
    font-family: var(--font-sans);
    font-weight: 300;
    font-size: 28px;
    color: var(--color-text);
    margin: 0;
  }

  .bg-color-box .banner-nav {
    height: 56px;
    width: var(--container-width);
    max-width: calc(100% - 40px);
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .bg-color-box .banner-nav .item-box {
    width: 175px;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
  }

  .bg-color-box .banner-nav .item-box .item-title {
    color: var(--color-text);
    font-weight: 500;
    font-size: 23px;
    margin-bottom: 3px;
  }

.bg-color-box .banner-nav .item-box .item-desc {
  color: var(--color-muted);
  font-size: 15px;
}

.bg-color-box .banner-nav .item-line {
  width: 1px;
  height: 60%;
  background: var(--color-divider);
}

.bg-color-box .banner-nav a.item-box {
  color: inherit;
  text-decoration: none;
  cursor: pointer;
}

.bg-color-box .banner-nav a.item-box:hover .item-title {
  color: var(--color-primary);
}

.banner-visual {
    max-width: 420px;
  }

  .banner-visual img {
    width: 100%;
    height: auto;
    display: block;
  }
}

@media screen and (max-width: 768px) {
  .bg-color-box {
    padding-top: 64px;
    height: 104.65vw;
    min-height: 380px;
    padding-bottom: 4.65vw;
    box-sizing: border-box;
    background: linear-gradient(180deg, #f8f9fc 0%, #fff 100%);
  }

  .bg-color-box,
  .bg-color-box .banner-title-box {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
  }

  .bg-color-box .banner-title-box {
    height: calc(100% - 9.3vw);
    padding: 0 5vw;
  }

  .bg-color-box .banner-title-box .banner-title {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 6.98vw;
    text-align: center;
  }

  .bg-color-box .banner-title-box .banner-title .banner-title-weight {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 5.58vw;
    margin-bottom: 3.72vw;
    color: #000;
  }

  .bg-color-box .banner-title-box .banner-title .banner-title-item {
    font-family: var(--font-sans);
    font-weight: 300;
    font-size: 3.72vw;
    color: #000;
  }

  .bg-color-box .banner-nav {
    height: 9.3vw;
    min-height: 48px;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 0;
  }

  .bg-color-box .banner-nav .item-box {
    width: 25.35vw;
    min-width: 100px;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
  }

  .bg-color-box .banner-nav .item-box .item-title {
    color: var(--color-text);
    font-weight: 500;
    font-size: 3.72vw;
    margin-bottom: 0.7vw;
  }

  .bg-color-box .banner-nav .item-box .item-desc {
    color: var(--color-muted);
    font-size: 2.33vw;
  }

  .bg-color-box .banner-nav .item-line {
    width: 1px;
    height: 60%;
    background: var(--color-divider);
  }

  .banner-visual {
    display: none;
  }
}

/* ========== Sections (content system as bingoai.cn) ========== */
.section {
  padding: 80px 0;
  border-top: 1px solid var(--color-border);
}

.section-title {
  font-size: 28px;
  font-weight: 600;
  margin: 0 0 12px;
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

.section-desc {
  color: var(--color-muted);
  margin: 0 0 48px;
  max-width: 560px;
  font-size: 16px;
}

/* Page hero (inner pages) */
.page-hero {
  padding: 120px 0 60px;
  background: linear-gradient(180deg, #f8f9fc 0%, #fff 100%);
  border-bottom: 1px solid var(--color-border);
}

.page-title {
  font-size: 36px;
  font-weight: 600;
  margin: 0 0 12px;
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

.page-desc {
  color: var(--color-muted);
  margin: 0 0 24px;
  font-size: 18px;
  max-width: 560px;
}

.sub-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 16px;
}

.sub-nav a {
  color: var(--color-primary);
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 8px;
  background: rgba(4, 17, 40, 0.06);
}

.sub-nav a:hover {
  background: rgba(4, 17, 40, 0.12);
}

.breadcrumb {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 16px;
}

.breadcrumb a {
  color: var(--color-primary);
}

.breadcrumb .sep {
  margin: 0 8px;
}

.content-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.content-block.reverse {
  direction: rtl;
}

.content-block.reverse > * {
  direction: ltr;
}

.content-media img {
  width: 100%;
  height: auto;
  border-radius: 12px;
  border: 1px solid var(--color-border);
}

.content-text .section-title {
  margin-top: 0;
}

.content-list {
  margin: 16px 0;
  padding-left: 24px;
  color: var(--color-muted);
}

.content-list li {
  margin-bottom: 8px;
}

.link-arrow {
  color: var(--color-primary);
  font-weight: 500;
}

.link-arrow:hover {
  text-decoration: underline;
}

.related-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.card-link {
  display: block;
  color: inherit;
  text-decoration: none;
}

.card-link .link-arrow {
  display: inline-block;
  margin-top: 12px;
  font-size: 14px;
}

.card-link:hover {
  border-color: rgba(4, 17, 40, 0.2);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

.product-item .link-arrow {
  display: inline-block;
  margin: 12px 24px 24px;
  font-size: 14px;
}

.download-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.download-item {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 24px;
  align-items: start;
  padding: 24px;
  background: #f8f9fc;
  border: 1px solid var(--color-border);
  border-radius: 12px;
}

.download-icon {
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #fff;
  border-radius: 8px;
  border: 1px solid var(--color-border);
}

.download-icon img {
  width: 48px;
  height: 48px;
  object-fit: contain;
}

.download-info h3 {
  margin: 0 0 8px;
  font-size: 20px;
  color: var(--color-primary);
}

.download-info p {
  margin: 0 0 16px;
  color: var(--color-muted);
  font-size: 15px;
}

@media (max-width: 768px) {
  .page-hero {
    padding: 100px 0 40px;
  }

  .page-title {
    font-size: 28px;
  }

  .content-block,
  .content-block.reverse {
    grid-template-columns: 1fr;
    direction: ltr;
  }

  .download-item {
    grid-template-columns: 1fr;
  }
}

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.card {
  background: #f8f9fc;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 32px;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.card:hover {
  border-color: rgba(4, 17, 40, 0.2);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

.card-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

.card-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.card h3 {
  font-size: 20px;
  font-weight: 600;
  margin: 0 0 8px;
  color: var(--color-primary);
}

.card p {
  color: var(--color-muted);
  margin: 0;
  font-size: 15px;
  line-height: 1.6;
}

/* Products */
.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 32px;
}

.product-item {
  background: #f8f9fc;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  overflow: hidden;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.product-item:hover {
  border-color: rgba(4, 17, 40, 0.2);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

.product-img {
  aspect-ratio: 16/10;
  background: #eef0f5;
  overflow: hidden;
}

.product-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.product-item h3 {
  font-size: 20px;
  font-weight: 600;
  margin: 20px 24px 0;
  color: var(--color-primary);
}

.product-item p {
  color: var(--color-muted);
  margin: 8px 24px 24px;
  font-size: 15px;
}

/* About */
.about-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.about-content .section-title {
  margin-bottom: 16px;
}

.about-content p {
  color: var(--color-muted);
  margin: 0 0 16px;
  font-size: 16px;
}

.about-image {
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.about-image img {
  width: 100%;
  height: auto;
  display: block;
}

@media (max-width: 768px) {
  .about-inner {
    grid-template-columns: 1fr;
  }

  .about-image {
    order: -1;
  }

  .section {
    padding: 50px 0;
  }
}

/* Contact */
.contact-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.contact-info p {
  margin: 0 0 20px;
  color: var(--color-muted);
  font-size: 16px;
}

.contact-info a {
  color: var(--color-primary);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 400px;
}

.contact-form label {
  font-weight: 600;
  font-size: 14px;
  color: var(--color-text);
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 16px;
  font-family: inherit;
  font-size: 16px;
  background: #f8f9fc;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  color: var(--color-text);
  transition: border-color 0.2s;
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--color-primary);
}

.contact-form textarea {
  resize: vertical;
  min-height: 120px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-family: inherit;
  font-size: 16px;
  font-weight: 600;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.btn-primary:hover {
  background: #0a1f3d;
  border-color: #0a1f3d;
  color: #fff;
}

@media (max-width: 768px) {
  .contact-row {
    grid-template-columns: 1fr;
  }

  .contact-form {
    max-width: none;
  }
}

/* ========== Footer (aligned with bingoai.cn content system) ========== */
.footer {
  border-top: 1px solid var(--color-border);
  padding: 40px 0;
  background: #f8f9fc;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.footer-brand .logo-text {
  font-weight: 600;
  font-size: 18px;
  color: var(--color-primary);
}

.footer-brand p {
  margin: 4px 0 0;
  font-size: 14px;
  color: var(--color-muted);
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--color-muted);
  font-size: 15px;
}

.footer-links a:hover {
  color: var(--color-text);
}

.footer-copy {
  width: 100%;
  margin: 0;
  font-size: 14px;
  color: var(--color-muted);
  text-align: center;
}

@media (min-width: 769px) {
  .footer-copy {
    width: auto;
    text-align: right;
  }
}