:root {
  --ink: #14213d;
  --muted: #627089;
  --line: #dbe4f0;
  --bg: #f6f9fe;
  --card: #ffffff;
  --blue: #315cf6;
  --cyan: #2fb7d8;
  --violet: #7657f5;
  --shadow: 0 20px 60px rgba(37, 65, 110, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: radial-gradient(circle at top left, rgba(49, 92, 246, 0.12), transparent 32%), var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.75;
}

a {
  color: inherit;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

.container {
  width: min(1160px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(246, 249, 254, 0.82);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(219, 228, 240, 0.78);
}

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

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 0;
  font-weight: 800;
  text-decoration: none;
  letter-spacing: 0.02em;
}

.brand img {
  border-radius: 14px;
  box-shadow: 0 8px 20px rgba(49, 92, 246, 0.18);
}

.site-nav,
.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.site-nav a,
.site-footer a {
  color: var(--muted);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 999px;
}

.site-nav a:hover,
.site-footer a:hover {
  color: var(--blue);
  background: rgba(49, 92, 246, 0.08);
}

.hero {
  padding: 78px 0 54px;
}

.hero-grid,
.split,
.content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
  gap: 42px;
  align-items: center;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--blue);
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 13px;
}

h1,
h2,
h3 {
  line-height: 1.2;
}

h1 {
  margin: 0;
  font-size: clamp(38px, 7vw, 74px);
  letter-spacing: -0.06em;
}

h2 {
  margin: 0 0 12px;
  font-size: clamp(28px, 4vw, 44px);
  letter-spacing: -0.04em;
}

h3 {
  margin: 0 0 10px;
  font-size: 20px;
}

.hero-text {
  max-width: 700px;
  color: var(--muted);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 16px;
  font-weight: 800;
  text-decoration: none;
  border: 1px solid var(--line);
}

.btn.primary {
  color: #fff;
  background: linear-gradient(135deg, var(--blue), var(--violet));
  border-color: transparent;
  box-shadow: 0 14px 30px rgba(49, 92, 246, 0.25);
}

.btn.ghost {
  background: rgba(255, 255, 255, 0.72);
}

.hero-panel {
  position: relative;
  padding: 14px;
  background: linear-gradient(145deg, rgba(255,255,255,0.78), rgba(224,235,255,0.78));
  border: 1px solid rgba(255,255,255,0.8);
  border-radius: 32px;
  box-shadow: var(--shadow);
}

.hero-panel img {
  border-radius: 24px;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.panel-card {
  margin: -44px 18px 8px;
  position: relative;
  padding: 18px;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid rgba(219, 228, 240, 0.9);
  border-radius: 22px;
  box-shadow: 0 16px 36px rgba(20, 33, 61, 0.12);
}

.panel-card p,
.section-head p,
.info-card p,
.article-row p,
.steps p,
.site-footer p,
.article-body p,
.article-body li,
.tagline {
  color: var(--muted);
}

.section {
  padding: 66px 0;
}

.section.soft {
  background: linear-gradient(135deg, rgba(255,255,255,0.7), rgba(230,238,255,0.74));
  border-block: 1px solid rgba(219, 228, 240, 0.8);
}

.section-head {
  max-width: 760px;
  margin-bottom: 28px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.info-card,
.steps article,
.article-row,
.toc-card,
.tag-chip,
.article-body,
.side-card {
  background: rgba(255,255,255,0.86);
  border: 1px solid rgba(219, 228, 240, 0.92);
  border-radius: 24px;
  box-shadow: 0 12px 34px rgba(20, 33, 61, 0.06);
}

.info-card {
  min-height: 188px;
  padding: 22px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.info-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 18px 42px rgba(20, 33, 61, 0.12);
}

.info-card a,
.article-row a,
.toc-card a,
.tag-chip {
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
}

.info-card a:hover,
.article-row a:hover,
.toc-card a:hover {
  color: var(--blue);
}

.steps {
  display: grid;
  gap: 16px;
}

.steps article {
  padding: 22px;
}

.article-list,
.toc-list {
  display: grid;
  gap: 18px;
}

.article-row {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 22px;
  padding: 16px;
  align-items: center;
}

.article-row img {
  border-radius: 18px;
  aspect-ratio: 11 / 7;
  object-fit: cover;
}

.article-row span,
.meta {
  color: #7c8aa1;
  font-size: 14px;
}

.site-footer {
  padding: 34px 0;
  border-top: 1px solid rgba(219, 228, 240, 0.9);
  background: rgba(255,255,255,0.72);
}

.page-hero {
  padding: 58px 0 32px;
}

.toc-card {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 22px;
  padding: 18px;
}

.toc-card img {
  border-radius: 20px;
  aspect-ratio: 12 / 8;
  object-fit: cover;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 12px;
}

.tag-chip {
  display: inline-flex;
  padding: 7px 12px;
  border-radius: 999px;
  font-size: 13px;
}

.article-shell {
  padding: 44px 0 72px;
}

.content-grid {
  align-items: start;
  grid-template-columns: minmax(0, 760px) minmax(260px, 1fr);
}

.article-body {
  padding: clamp(24px, 5vw, 44px);
}

.article-body h1 {
  font-size: clamp(32px, 5vw, 54px);
}

.article-body h2 {
  margin-top: 38px;
  font-size: 28px;
}

.article-body h3 {
  margin-top: 26px;
}

.article-body img {
  margin: 24px 0;
  border-radius: 24px;
  box-shadow: 0 16px 40px rgba(20, 33, 61, 0.12);
}

.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 22px 0;
  overflow: hidden;
  border-radius: 16px;
}

.article-body th,
.article-body td {
  padding: 12px 14px;
  border: 1px solid var(--line);
  text-align: left;
}

.article-body th {
  background: #edf3ff;
}

.side-card {
  padding: 22px;
  position: sticky;
  top: 86px;
}

.video-frame {
  padding: 18px;
  margin: 24px 0;
  border-radius: 24px;
  background: #0f172a;
  color: #fff;
}

.video-screen {
  display: grid;
  min-height: 260px;
  place-items: center;
  text-align: center;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(49, 92, 246, 0.8), rgba(47, 183, 216, 0.78)), url("https://tse-mm.bing.com/th?q=DeepSeek+Windows+install+video");
  background-size: cover;
  background-position: center;
}

.video-screen span {
  display: inline-flex;
  width: 72px;
  height: 72px;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(255,255,255,0.92);
  color: var(--blue);
  font-size: 32px;
  margin-bottom: 12px;
}

@media (max-width: 980px) {
  .hero-grid,
  .split,
  .content-grid {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 680px) {
  .container {
    width: min(100% - 24px, 1160px);
  }

  .nav-wrap,
  .footer-grid {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-nav a {
    padding-left: 0;
  }

  .hero {
    padding-top: 46px;
  }

  .card-grid,
  .article-row,
  .toc-card {
    grid-template-columns: 1fr;
  }

  .info-card {
    min-height: auto;
  }
}

.legacy-home {
  margin: 0;
  background: #fff;
  font-family: Arial, sans-serif;
}

.legacy-home header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px;
  position: relative;
  z-index: 2;
}

.legacy-home .logo {
  height: 24px;
}

.legacy-home .text-logo,
.legacy-home .footer-text-logo {
  color: #1e293b;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.legacy-home nav a {
  margin-left: 15px;
  text-decoration: none;
  color: #333;
}

.legacy-home nav .tips-link {
  color: #4d6bfe;
  font-weight: 700;
}

.legacy-home .banner {
  background: linear-gradient(to bottom right, #f0f8ff, #add8e6);
  text-align: center;
  background-repeat: no-repeat;
  background-size: cover;
  background-image: url(banner-background.webp);
  margin-top: -60px;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 158px 50px;
}

.legacy-home .update-notice {
  margin-bottom: 40px;
  color: #94a3b8;
  font-size: 14px;
}

.legacy-home .main-title {
  font-size: 48px;
  color: #007bff;
  margin-bottom: 20px;
  letter-spacing: normal;
}

.legacy-home .main-title svg {
  height: 60px;
}

.legacy-home .slogan {
  font-size: 30px;
  color: #475569;
  margin-bottom: 30px;
  font-weight: bold;
}

.legacy-home .button-container {
  display: flex;
  justify-content: center;
  gap: 30px;
}

.legacy-home .start-chat-button,
.legacy-home .get-app-button {
  text-decoration: none;
  background-color: #fff;
  border: 1px solid #f9f9f9;
  border-radius: 20px;
  padding: 20px 30px;
  text-align: left;
  display: inline-block;
  transition: background-color 0.3s ease;
  box-shadow: 0 0 0 1px #f1f5f9, 0 2px 4px rgba(0, 0, 0, .05), 0 12px 24px rgba(0, 0, 0, .05);
  width: 280px;
}

.legacy-home .start-chat-button:hover,
.legacy-home .get-app-button:hover {
  background-color: #e9ecef;
}

.legacy-home .button-content h3 {
  color: #4d6bfe;
  margin-bottom: 10px;
}

.legacy-home .button-content p {
  color: #64748b;
  font-size: 15px;
}

.legacy-home footer {
  background-color: #f8f9fa;
  padding: 40px 20px;
  text-align: center;
}

.legacy-home .footer-logo-container {
  margin-bottom: 20px;
}

.legacy-home .footer-logo-container .social-icons {
  display: flex;
}

.legacy-home .footer-logo {
  height: 24px;
  margin-bottom: 20px;
}

.legacy-home .social-icons a {
  margin-right: 10px;
  display: contents;
  color: #94a3b8;
}

.legacy-home .social-icons svg,
.legacy-home .social-icons img {
  height: 20px;
}

.legacy-home .footer-links {
  justify-content: center;
  margin-bottom: 20px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 30px;
  max-width: 1200px;
  margin: auto;
}

.legacy-home .link-column {
  text-align: left;
}

.legacy-home .link-column h4 {
  color: #333;
  margin-bottom: 10px;
  font-size: 16px;
}

.legacy-home .link-column a {
  display: block;
  margin-bottom: 15px;
  text-decoration: none;
  color: #666;
  font-size: 14px;
  transition: color 0.3s ease;
}

.legacy-home .link-column a:hover {
  color: #007bff;
}

.legacy-home .copyright {
  color: #666;
  font-size: 14px;
}

.legacy-home #auth-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

.legacy-home #auth-dialog {
  background: #fff;
  border-radius: 20px;
  padding: 40px;
  text-align: center;
  max-width: 400px;
  width: 90%;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.legacy-home .auth-lock-icon {
  margin-bottom: 20px;
}

.legacy-home #auth-title {
  font-size: 24px;
  color: #1e293b;
  margin-bottom: 10px;
}

.legacy-home #auth-desc {
  color: #64748b;
  font-size: 14px;
  margin-bottom: 30px;
  line-height: 1.6;
}

.legacy-home .auth-btn-group {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.legacy-home .auth-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 14px 20px;
  border-radius: 12px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  font-size: 16px;
}

.legacy-home .auth-btn-whatsapp {
  background-color: #25D366;
  color: #fff;
}

.legacy-home .auth-btn-whatsapp:hover {
  background-color: #1ebe5a;
}

.legacy-home .auth-btn__icon {
  display: flex;
  align-items: center;
}

.legacy-home .auth-note {
  margin-top: 20px;
  font-size: 12px;
  color: #94a3b8;
}

@media (max-width: 680px) {
  .legacy-home header {
    align-items: flex-start;
    gap: 12px;
    flex-direction: column;
  }

  .legacy-home nav a {
    margin: 0 12px 0 0;
  }

  .legacy-home .banner {
    margin-top: -20px;
    padding: 100px 18px 80px;
  }

  .legacy-home .button-container {
    flex-direction: column;
  }
}