:root {
  color-scheme: light;
  --bg: #f6f8fb;
  --surface: #ffffff;
  --surface-strong: #eef4ff;
  --ink: #172033;
  --muted: #5e6b80;
  --line: #dce3ee;
  --primary: #1867c9;
  --primary-strong: #0d4f9e;
  --accent: #12836f;
  --warning: #ad6200;
  --error: #b3261e;
  --shadow: 0 20px 60px rgba(24, 42, 70, 0.14);
  --radius: 8px;
  --header-height: 76px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Noto Sans SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.5;
  letter-spacing: 0;
}

button,
input {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

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

svg {
  display: block;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.8;
}

:focus-visible {
  outline: 3px solid rgba(24, 103, 201, 0.35);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  left: 16px;
  top: 16px;
  z-index: 20;
  transform: translateY(-140%);
  border-radius: var(--radius);
  background: var(--ink);
  color: #fff;
  padding: 10px 14px;
  transition: transform 160ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height);
  padding: 14px clamp(18px, 4vw, 56px);
  border-bottom: 1px solid rgba(220, 227, 238, 0.88);
  background: rgba(246, 248, 251, 0.94);
  backdrop-filter: blur(18px);
}

.brand,
.header-actions,
.desktop-nav,
.hero-actions,
.form-row,
.status-header,
.viewer-topbar,
.viewer-footer,
.session-title {
  display: flex;
  align-items: center;
}

.brand {
  gap: 10px;
  min-height: 44px;
  font-size: 1.05rem;
  font-weight: 750;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius);
  background: var(--ink);
  color: #fff;
}

.brand-mark svg {
  width: 22px;
  height: 22px;
}

.desktop-nav {
  gap: 6px;
  color: var(--muted);
  font-weight: 650;
}

.desktop-nav a {
  min-height: 44px;
  border-radius: var(--radius);
  padding: 10px 12px;
}

.desktop-nav a:hover {
  background: #eaf1fb;
  color: var(--ink);
}

.header-actions {
  gap: 10px;
}

.language-toggle {
  display: flex;
  min-height: 44px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.lang-option,
.login-link,
.primary-action,
.secondary-action,
.back-link,
.submit-button,
.icon-button {
  min-height: 44px;
  border: 0;
  border-radius: var(--radius);
  cursor: pointer;
}

.lang-option {
  min-width: 52px;
  background: transparent;
  color: var(--muted);
  font-weight: 750;
}

.lang-option.is-active {
  background: var(--ink);
  color: #fff;
}

.login-link,
.primary-action,
.submit-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: var(--primary);
  color: #fff;
  font-weight: 750;
  transition: background 180ms ease, transform 180ms ease;
}

.login-link {
  padding: 0 16px;
}

.login-link svg,
.primary-action svg,
.back-link svg {
  width: 20px;
  height: 20px;
}

.login-link:hover,
.primary-action:hover,
.submit-button:hover {
  background: var(--primary-strong);
}

.login-link:active,
.primary-action:active,
.submit-button:active {
  transform: translateY(1px);
}

.page {
  display: none;
}

.page.is-active {
  display: block;
}

.hero-shell {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(360px, 1.08fr);
  gap: clamp(28px, 5vw, 72px);
  align-items: center;
  min-height: calc(100dvh - var(--header-height));
  padding: clamp(42px, 6vw, 80px) clamp(18px, 4vw, 56px) 44px;
}

.hero-copy {
  max-width: 680px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary-strong);
  font-size: 0.84rem;
  font-weight: 800;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 20px;
  font-size: clamp(2.35rem, 7vw, 5.9rem);
  line-height: 1.03;
  font-weight: 820;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(1.8rem, 4vw, 3.4rem);
  line-height: 1.12;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.04rem;
}

.hero-text {
  max-width: 620px;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.28rem);
}

.hero-actions {
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  max-width: 620px;
  margin-top: 30px;
}

.hero-metrics span {
  min-height: 86px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.72);
  padding: 14px;
}

.hero-metrics strong,
.hero-metrics small {
  display: block;
}

.hero-metrics strong {
  margin-bottom: 4px;
  font-size: 1.36rem;
  line-height: 1.15;
}

.hero-metrics small {
  color: var(--muted);
  font-weight: 700;
}

.primary-action,
.secondary-action {
  padding: 0 18px;
}

.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  font-weight: 750;
}

.secondary-action:hover {
  border-color: #b8c7da;
  background: #f9fbfe;
}

.viewer-visual {
  overflow: hidden;
  border: 1px solid #c7d4e7;
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.viewer-topbar,
.viewer-footer {
  justify-content: space-between;
  gap: 12px;
  min-height: 48px;
  padding: 0 16px;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 700;
}

.viewer-time {
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.session-title {
  gap: 10px;
  min-width: 0;
}

.status-dot {
  display: inline-block;
  flex: 0 0 auto;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #159b7f;
  box-shadow: 0 0 0 5px rgba(21, 155, 127, 0.12);
}

.shared-screen {
  display: grid;
  grid-template-columns: 76px 1fr;
  min-height: 430px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: #eef4fb;
}

.mock-sidebar {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 22px 18px;
  background: #1d2b3f;
}

.mock-sidebar span {
  width: 34px;
  height: 34px;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.2);
}

.mock-content {
  position: relative;
  display: grid;
  grid-template-rows: 56px 130px 1fr;
  gap: 18px;
  padding: 22px;
}

.mock-toolbar,
.mock-grid,
.mock-chart {
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid #d7e0eb;
}

.mock-toolbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 14px;
}

.mock-toolbar span {
  height: 12px;
  border-radius: 999px;
  background: #c6d3e3;
}

.mock-toolbar span:nth-child(1) {
  width: 120px;
}

.mock-toolbar span:nth-child(2) {
  width: 74px;
}

.mock-toolbar span:nth-child(3) {
  width: 92px;
  margin-left: auto;
  background: rgba(18, 131, 111, 0.22);
}

.mock-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  padding: 14px;
}

.mock-grid span {
  border-radius: var(--radius);
  background: linear-gradient(180deg, #f6f9fd, #e4ebf5);
}

.mock-chart {
  display: flex;
  align-items: end;
  gap: 18px;
  padding: 26px;
}

.mock-chart span {
  flex: 1;
  min-height: 64px;
  border-radius: 6px 6px 0 0;
  background: linear-gradient(180deg, #1867c9, #12836f);
}

.session-card {
  position: absolute;
  right: 34px;
  bottom: 34px;
  width: min(260px, calc(100% - 68px));
  border: 1px solid rgba(24, 103, 201, 0.2);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 16px 36px rgba(23, 32, 51, 0.14);
  padding: 16px;
}

.session-card span,
.session-card strong,
.session-card small {
  display: block;
}

.session-card span {
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 800;
}

.session-card strong {
  margin: 4px 0;
  font-size: 1.08rem;
}

.session-card small {
  color: var(--accent);
  font-weight: 750;
}

.trust-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  margin: 0 clamp(18px, 4vw, 56px);
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--line);
}

.trust-strip span {
  min-height: 70px;
  display: grid;
  place-items: center;
  background: rgba(255, 255, 255, 0.76);
  color: var(--muted);
  padding: 14px;
  text-align: center;
  font-weight: 800;
}

.section-band {
  padding: clamp(54px, 7vw, 92px) clamp(18px, 4vw, 56px);
}

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

.section-heading p,
.split-layout p {
  color: var(--muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card,
.steps article,
.login-panel,
.status-panel,
.use-case-grid article,
.workspace-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.feature-card {
  padding: 24px;
}

.feature-card p,
.steps p {
  margin-bottom: 0;
  color: var(--muted);
}

.feature-icon {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  margin-bottom: 18px;
  border-radius: var(--radius);
  background: var(--surface-strong);
  color: var(--primary);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
}

.use-case-band {
  background: #f8fafc;
}

.use-case-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.use-case-grid article {
  min-height: 220px;
  padding: 24px;
}

.use-case-grid span {
  display: inline-flex;
  min-height: 30px;
  align-items: center;
  margin-bottom: 36px;
  border-radius: 999px;
  background: #eaf1fb;
  color: var(--primary-strong);
  padding: 0 10px;
  font-size: 0.78rem;
  font-weight: 850;
}

.use-case-grid p {
  color: var(--muted);
}

.security-band {
  background: #edf5f2;
}

.split-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 420px);
  gap: 36px;
  align-items: center;
}

.check-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding: 14px 16px 14px 42px;
  border: 1px solid rgba(18, 131, 111, 0.22);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.75);
  font-weight: 750;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 19px;
  width: 12px;
  height: 7px;
  border-bottom: 2px solid var(--accent);
  border-left: 2px solid var(--accent);
  transform: rotate(-45deg);
}

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

.steps article {
  min-height: 190px;
  padding: 24px;
}

.steps span {
  display: inline-block;
  margin-bottom: 24px;
  color: var(--warning);
  font-weight: 850;
}

.page-login {
  min-height: calc(100dvh - var(--header-height));
  padding: clamp(28px, 6vw, 64px) clamp(18px, 4vw, 56px);
}

.login-layout {
  display: grid;
  grid-template-columns: minmax(320px, 520px) minmax(280px, 1fr);
  gap: clamp(24px, 5vw, 72px);
  align-items: center;
  max-width: 1180px;
  margin: 0 auto;
}

.login-panel {
  padding: clamp(24px, 4vw, 40px);
  box-shadow: var(--shadow);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 26px;
  padding: 0 12px;
  background: #edf2f8;
  color: var(--ink);
  font-weight: 750;
}

.login-subtitle {
  margin-bottom: 28px;
  color: var(--muted);
}

.login-form {
  display: grid;
  gap: 18px;
}

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

.field label {
  color: var(--ink);
  font-weight: 750;
}

.field input {
  width: 100%;
  min-height: 50px;
  border: 1px solid #bfccda;
  border-radius: var(--radius);
  background: #fff;
  color: var(--ink);
  padding: 0 14px;
}

.field input:focus {
  border-color: var(--primary);
}

.password-control {
  position: relative;
}

.password-control input {
  padding-right: 58px;
}

.icon-button {
  position: absolute;
  right: 4px;
  top: 3px;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  background: transparent;
  color: var(--muted);
}

.icon-button:hover {
  background: #eef3f8;
  color: var(--ink);
}

.icon-button svg {
  width: 22px;
  height: 22px;
}

.form-row {
  justify-content: space-between;
  gap: 14px;
  color: var(--muted);
  font-size: 0.94rem;
}

.checkbox-row {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
}

.checkbox-row input {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
}

.form-row a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  color: var(--primary-strong);
  font-weight: 750;
}

.form-error {
  min-height: 24px;
  margin: 0;
  color: var(--error);
  font-weight: 700;
}

.submit-button {
  width: 100%;
  min-height: 52px;
  padding: 0 18px;
}

.button-spinner {
  display: none;
  width: 18px;
  height: 18px;
  border: 2px solid rgba(255, 255, 255, 0.42);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 800ms linear infinite;
}

.submit-button.is-loading .button-spinner {
  display: inline-block;
}

.submit-button.is-loading {
  cursor: wait;
}

.login-aside {
  min-height: 520px;
  display: grid;
  align-items: center;
}

.status-panel {
  overflow: hidden;
  min-height: 390px;
  padding: 24px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.86), rgba(255, 255, 255, 0.98)),
    repeating-linear-gradient(135deg, rgba(24, 103, 201, 0.08) 0 1px, transparent 1px 18px);
}

.status-header {
  gap: 12px;
  margin-bottom: 18px;
  font-weight: 800;
}

.workspace-card {
  margin-bottom: 24px;
  padding: 18px;
}

.workspace-card span,
.workspace-card strong,
.workspace-card small {
  display: block;
}

.workspace-card span {
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 800;
}

.workspace-card strong {
  margin-bottom: 6px;
}

.workspace-card small {
  color: var(--accent);
  font-weight: 750;
}

.status-lines {
  display: grid;
  gap: 14px;
  margin-bottom: 28px;
}

.status-lines span {
  height: 18px;
  border-radius: 999px;
  background: #dbe5f1;
}

.status-lines span:nth-child(1) {
  width: 72%;
}

.status-lines span:nth-child(2) {
  width: 88%;
}

.status-lines span:nth-child(3) {
  width: 58%;
}

.mini-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.mini-metrics span {
  min-height: 82px;
  border: 1px solid #d5dfeb;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.72);
  padding: 16px;
  color: var(--muted);
  font-weight: 750;
}

.audit-list {
  display: grid;
  gap: 10px;
  margin-top: 18px;
}

.audit-list span {
  position: relative;
  min-height: 42px;
  border: 1px solid rgba(18, 131, 111, 0.18);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.72);
  padding: 10px 12px 10px 36px;
  color: var(--muted);
  font-weight: 750;
}

.audit-list span::before {
  content: "";
  position: absolute;
  left: 14px;
  top: 17px;
  width: 10px;
  height: 6px;
  border-bottom: 2px solid var(--accent);
  border-left: 2px solid var(--accent);
  transform: rotate(-45deg);
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 900px) {
  .desktop-nav {
    display: none;
  }

  .hero-shell,
  .login-layout,
  .split-layout {
    grid-template-columns: 1fr;
  }

  .hero-shell {
    min-height: auto;
  }

  .viewer-visual {
    order: -1;
  }

  .feature-grid,
  .steps,
  .use-case-grid,
  .trust-strip {
    grid-template-columns: 1fr;
  }

  .login-aside {
    min-height: auto;
  }
}

@media (max-width: 620px) {
  .site-header {
    align-items: stretch;
    flex-wrap: wrap;
    gap: 10px;
  }

  .brand {
    flex: 1 0 180px;
  }

  .header-actions {
    width: 100%;
    justify-content: space-between;
  }

  .language-toggle,
  .login-link {
    flex: 1;
  }

  .login-link {
    min-width: 0;
  }

  .shared-screen {
    grid-template-columns: 48px 1fr;
    min-height: 320px;
  }

  .mock-sidebar {
    padding: 16px 10px;
  }

  .mock-sidebar span {
    width: 28px;
    height: 28px;
  }

  .mock-content {
    grid-template-rows: 48px 104px 1fr;
    gap: 12px;
    padding: 14px;
  }

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

  .mock-chart {
    gap: 10px;
    padding: 18px;
  }

  .session-card {
    right: 18px;
    bottom: 18px;
    width: min(230px, calc(100% - 36px));
  }

  .form-row,
  .viewer-footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero-metrics,
  .mini-metrics {
    grid-template-columns: 1fr;
  }
}