:root {
  --ms-blue: #0078d4;
  --ms-blue-dark: #005a9e;
  --ms-blue-light: #e8f4fc;
  --ms-green: #107c10;
  --text: #1b1b1b;
  --text-muted: #5c5c5c;
  --border: #e5e5e5;
  --bg: #f3f6f9;
  --white: #ffffff;
  --shadow: 0 8px 28px rgba(0, 60, 120, 0.08);
  --radius: 12px;
  --max: 1120px;
  --font: "Segoe UI", "Microsoft YaHei UI", "Microsoft YaHei", "PingFang SC", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  padding-bottom: 88px;
}

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

a {
  color: var(--ms-blue);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: min(100% - 32px, var(--max));
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 1.05rem;
  text-decoration: none;
}

.logo:hover {
  text-decoration: none;
  color: var(--ms-blue);
}

.logo-mark {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  object-fit: cover;
  display: block;
  flex-shrink: 0;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  align-items: center;
}

.nav a {
  color: var(--text-muted);
  font-size: 0.95rem;
  text-decoration: none;
}

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

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--white);
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  flex-shrink: 0;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.site-header.nav-open .nav-toggle span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-header.nav-open .nav-toggle span:nth-child(2) {
  opacity: 0;
}

.site-header.nav-open .nav-toggle span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  border-radius: 999px;
  padding: 12px 22px;
  font: inherit;
  font-weight: 650;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--ms-blue);
  color: #fff;
  box-shadow: 0 6px 18px rgba(0, 120, 212, 0.28);
}

.btn-primary:hover {
  background: var(--ms-blue-dark);
  color: #fff;
}

.btn-secondary {
  background: var(--white);
  color: var(--ms-blue);
  border: 1px solid #cce4f7;
}

.btn-secondary:hover {
  background: var(--ms-blue-light);
  color: var(--ms-blue-dark);
}

.btn-lg {
  padding: 14px 28px;
  font-size: 1.05rem;
}

/* Hero */
.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(ellipse 80% 60% at 90% 10%, rgba(0, 164, 239, 0.18), transparent 55%),
    radial-gradient(ellipse 60% 50% at 0% 100%, rgba(0, 120, 212, 0.12), transparent 50%),
    linear-gradient(180deg, #ffffff 0%, #eef5fb 100%);
  border-bottom: 1px solid var(--border);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
  padding: 56px 0 64px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--ms-blue-light);
  color: var(--ms-blue-dark);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.hero h1 {
  margin: 0 0 14px;
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.hero-lead {
  margin: 0 0 22px;
  color: var(--text-muted);
  font-size: 1.08rem;
  max-width: 36em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 22px;
}

.trust-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  padding: 0;
  margin: 0;
  list-style: none;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.trust-list li::before {
  content: "✓";
  color: var(--ms-green);
  font-weight: 700;
  margin-right: 6px;
}

.hero-visual {
  border-radius: 18px;
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 255, 255, 0.8);
  background: #fff;
}

.hero-visual img {
  width: 100%;
  aspect-ratio: 16 / 11;
  object-fit: cover;
}

/* Sections */
.section {
  padding: 64px 0;
}

.section-alt {
  background: var(--white);
  border-block: 1px solid var(--border);
}

.section-head {
  max-width: 720px;
  margin-bottom: 36px;
}

.section-head h2 {
  margin: 0 0 10px;
  font-size: clamp(1.45rem, 2.5vw, 1.85rem);
  letter-spacing: -0.02em;
}

.section-head p {
  margin: 0;
  color: var(--text-muted);
}

.grid-3,
.grid-2 {
  display: grid;
  gap: 20px;
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

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

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.02);
}

.section-alt .card {
  background: var(--bg);
}

.card h3 {
  margin: 0 0 8px;
  font-size: 1.1rem;
}

.card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.card-icon {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: var(--ms-blue-light);
  color: var(--ms-blue);
  font-weight: 800;
  margin-bottom: 14px;
}

.feature-media {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: #fff;
}

.feature-media img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
}

.feature-row.reverse .feature-copy {
  order: 2;
}

.feature-row.reverse .feature-media {
  order: 1;
}

.feature-copy h3 {
  margin: 0 0 10px;
  font-size: 1.35rem;
}

.feature-copy p {
  margin: 0 0 14px;
  color: var(--text-muted);
}

.feature-copy ul {
  margin: 0;
  padding-left: 1.15em;
  color: var(--text-muted);
}

.feature-copy li + li {
  margin-top: 6px;
}

/* Steps */
.steps {
  display: grid;
  gap: 16px;
  counter-reset: step;
}

.step {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 16px;
  align-items: start;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.step-num {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--ms-blue);
  color: #fff;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 1.1rem;
}

.step h3 {
  margin: 4px 0 6px;
  font-size: 1.05rem;
}

.step p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Visual guide steps (activate tutorial) */
.guide-steps {
  display: grid;
  gap: 28px;
}

.guide-step {
  display: grid;
  gap: 18px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow);
}

.guide-step-copy {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 16px;
  align-items: start;
}

.guide-step-copy h3 {
  margin: 4px 0 8px;
  font-size: 1.15rem;
}

.guide-step-copy p {
  margin: 0 0 12px;
  color: var(--text-muted);
}

.tip-list {
  margin: 0;
  padding-left: 1.15em;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.tip-list li + li {
  margin-top: 6px;
}

.guide-shot {
  margin: 0;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #0b0b0b;
}

.guide-shot img {
  width: 100%;
  aspect-ratio: auto;
  object-fit: contain;
  background: #111;
}

.guide-shot figcaption {
  padding: 10px 14px;
  font-size: 0.88rem;
  color: var(--text-muted);
  background: var(--white);
  border-top: 1px solid var(--border);
}

.kbd {
  display: inline-block;
  padding: 1px 7px;
  border-radius: 6px;
  background: #f0f0f0;
  border: 1px solid #ddd;
  font-size: 0.88em;
  font-family: Consolas, "Courier New", monospace;
}

/* Table */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--white);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

th,
td {
  text-align: left;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  background: var(--ms-blue-light);
  color: var(--ms-blue-dark);
  font-weight: 650;
}

tr:last-child td {
  border-bottom: none;
}

/* FAQ */
.faq details {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 18px;
  margin-bottom: 10px;
}

.faq summary {
  cursor: pointer;
  font-weight: 650;
  list-style: none;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "+";
  float: right;
  color: var(--ms-blue);
  font-weight: 700;
}

.faq details[open] summary::after {
  content: "–";
}

.faq details p {
  margin: 12px 0 4px;
  color: var(--text-muted);
}

/* CTA band */
.cta-band {
  background: linear-gradient(135deg, #0078d4, #005a9e 60%, #004578);
  color: #fff;
  border-radius: 18px;
  padding: 36px 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 12px 32px rgba(0, 90, 158, 0.28);
}

.cta-band h2 {
  margin: 0 0 8px;
  font-size: 1.45rem;
}

.cta-band p {
  margin: 0;
  opacity: 0.92;
  max-width: 40em;
}

.cta-band .btn-primary {
  background: #fff;
  color: var(--ms-blue-dark);
  box-shadow: none;
}

.cta-band .btn-primary:hover {
  background: #f3f8fc;
}

.notice {
  margin-top: 18px;
  padding: 14px 16px;
  border-radius: 10px;
  background: #fff8e8;
  border: 1px solid #f0dfa0;
  color: #6b5600;
  font-size: 0.92rem;
}

.breadcrumb {
  padding: 18px 0 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}

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

.page-hero {
  padding: 28px 0 8px;
}

.page-hero h1 {
  margin: 0 0 10px;
  font-size: clamp(1.6rem, 3vw, 2.1rem);
}

.page-hero p {
  margin: 0;
  color: var(--text-muted);
  max-width: 48em;
}

/* Footer */
.site-footer {
  background: #0f1c2e;
  color: #c9d4e0;
  padding: 48px 0 28px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 28px;
  margin-bottom: 28px;
}

.site-footer h3 {
  margin: 0 0 12px;
  color: #fff;
  font-size: 1rem;
}

.site-footer a {
  color: #c9d4e0;
}

.site-footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-footer li + li {
  margin-top: 8px;
}

.footer-brand {
  font-weight: 700;
  color: #fff;
  font-size: 1.1rem;
  margin-bottom: 10px;
}

.footer-note {
  font-size: 0.88rem;
  line-height: 1.6;
  opacity: 0.85;
  margin: 0 0 10px;
}

.footer-contact {
  margin: 14px 0 0;
  font-size: 0.9rem;
}

.footer-contact a {
  color: #9ec9f5;
  text-decoration: none;
  word-break: break-all;
}

.footer-contact a:hover {
  color: #fff;
  text-decoration: underline;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 18px;
  font-size: 0.85rem;
  opacity: 0.75;
}

/* Floating download bar */
.float-download {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 200;
  transform: translateY(110%);
  transition: transform 0.28s ease, opacity 0.28s ease;
  opacity: 0;
  pointer-events: none;
}

.float-download.show {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.float-inner {
  margin: 0 auto 12px;
  width: min(100% - 24px, 720px);
  background: rgba(15, 28, 46, 0.94);
  backdrop-filter: blur(10px);
  color: #fff;
  border-radius: 16px;
  padding: 12px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.28);
}

.float-inner strong {
  display: block;
  font-size: 0.95rem;
}

.float-inner span {
  font-size: 0.8rem;
  opacity: 0.78;
}

.float-inner .btn {
  padding: 10px 18px;
  white-space: nowrap;
}

/* Cover gallery */
.cover-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.cover-grid figure {
  margin: 0;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.cover-grid img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
}

.cover-grid figcaption {
  padding: 10px 12px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

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

.disclaimer .card h2 {
  margin: 0 0 10px;
  font-size: 1.15rem;
}

.disclaimer .card p {
  margin: 0 0 10px;
  color: var(--text-muted);
}

.disclaimer .card p:last-child {
  margin-bottom: 0;
}

.disclaimer-meta {
  margin-top: 12px !important;
  font-size: 0.88rem;
  opacity: 0.8;
}

.footer-bottom a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 2px;
}

@media (max-width: 960px) {
  .hero-grid,
  .feature-row,
  .feature-row.reverse,
  .footer-grid,
  .grid-3 {
    grid-template-columns: 1fr;
  }

  .feature-row.reverse .feature-copy,
  .feature-row.reverse .feature-media {
    order: initial;
  }

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

  .header-inner {
    flex-wrap: wrap;
    position: relative;
  }

  .nav-toggle {
    display: flex;
    margin-left: auto;
  }

  .header-cta {
    display: none;
  }

  .nav {
    display: none;
    width: 100%;
    order: 5;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 0 12px;
    border-top: 1px solid var(--border);
  }

  .site-header.nav-open .nav {
    display: flex;
  }

  .nav a {
    padding: 12px 4px;
    border-bottom: 1px solid var(--border);
    font-size: 1rem;
  }

  .nav a:last-child {
    border-bottom: none;
    color: #fff;
    background: var(--ms-blue);
    border-radius: 10px;
    margin-top: 10px;
    padding: 12px 16px;
    text-align: center;
    font-weight: 650;
  }

  .nav a:last-child:hover,
  .nav a:last-child.active {
    color: #fff;
    background: var(--ms-blue-dark);
  }

  .guide-step {
    padding: 16px;
  }
}

@media (max-width: 640px) {
  .grid-2,
  .cover-grid {
    grid-template-columns: 1fr;
  }

  .float-inner {
    flex-direction: column;
    align-items: stretch;
    text-align: center;
  }

  .cta-band {
    text-align: center;
    justify-content: center;
  }
}