:root {
  color-scheme: light;
  --ink: #172331;
  --ink-2: #324256;
  --muted: #647386;
  --line: #d9e2e8;
  --paper: #ffffff;
  --mist: #f4f8fa;
  --blue: #236996;
  --blue-dark: #174d72;
  --cyan: #4bbceb;
  --green: #25765d;
  --amber: #b56b17;
  --rose: #a64b5f;
  --shadow: 0 20px 50px rgba(28, 45, 60, 0.12);
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: #fbfcfd;
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px max(22px, calc((100vw - var(--max)) / 2));
  background: rgba(251, 252, 253, 0.9);
  border-bottom: 1px solid rgba(217, 226, 232, 0.84);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 190px;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 15px;
  line-height: 1.15;
}

.brand small {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.25;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--ink-2);
  font-size: 14px;
  font-weight: 650;
}

.site-nav a {
  border-radius: 6px;
  padding: 8px 11px;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  background: #edf4f7;
  outline: none;
}

.section-band {
  border-bottom: 1px solid var(--line);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 520px);
  align-items: center;
  gap: 44px;
  min-height: calc(100vh - 70px);
  padding: 58px max(22px, calc((100vw - var(--max)) / 2)) 54px;
  background:
    linear-gradient(115deg, rgba(75, 188, 235, 0.14), rgba(37, 118, 93, 0) 42%),
    linear-gradient(180deg, #fbfcfd 0%, #f4f8fa 100%);
}

.quiet-line {
  margin: 0 0 16px;
  color: var(--green);
  font-size: 14px;
  font-weight: 800;
}

.hero h1 {
  margin: 0;
  max-width: 660px;
  font-size: clamp(54px, 8vw, 108px);
  line-height: 0.92;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 650px;
  margin: 26px 0 0;
  color: var(--ink-2);
  font-size: clamp(18px, 2.2vw, 23px);
  line-height: 1.65;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  border-radius: 7px;
  padding: 0 18px;
  font-size: 14px;
  font-weight: 800;
  line-height: 1;
  transition:
    transform 160ms ease,
    background 160ms ease,
    border-color 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button:focus-visible {
  outline: 3px solid rgba(75, 188, 235, 0.38);
  outline-offset: 3px;
}

.button-primary {
  background: var(--blue-dark);
  color: #fff;
  box-shadow: 0 12px 26px rgba(23, 77, 114, 0.22);
}

.button-primary:hover {
  background: #0f3c5a;
}

.button-secondary {
  background: #fff;
  border-color: var(--line);
  color: var(--ink);
}

.hero-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  max-width: 690px;
  margin: 34px 0 0;
}

.hero-facts div {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  padding: 14px;
}

.hero-facts dt,
.meta-label {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
}

.hero-facts dd {
  margin: 4px 0 0;
  overflow-wrap: normal;
  color: var(--ink);
  font-size: 12px;
  font-weight: 800;
  line-height: 1.35;
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.hero-visual {
  align-self: end;
  justify-self: center;
  width: min(100%, 500px);
}

.hero-visual img {
  filter: drop-shadow(0 28px 44px rgba(26, 44, 60, 0.16));
}

.download-strip {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 430px);
  gap: 34px;
  align-items: center;
  padding: 46px max(22px, calc((100vw - var(--max)) / 2));
  background: #fff;
  border-bottom: 1px solid var(--line);
}

.download-strip h2,
.section-heading h2,
.privacy-section h2,
.admin-heading h1 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(30px, 4.4vw, 54px);
  line-height: 1.05;
  letter-spacing: 0;
}

.download-strip p,
.section-heading p,
.privacy-section p,
.admin-heading p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.download-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  border: 1px solid var(--line);
  border-left: 6px solid var(--cyan);
  border-radius: 8px;
  padding: 18px;
  background: var(--mist);
}

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

.download-card strong {
  margin-top: 4px;
  font-size: 18px;
}

.download-card small {
  max-width: 260px;
  margin-top: 5px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.45;
}

.studio-section,
.app-section,
.privacy-section,
.log-section,
.faq-section {
  padding: 78px max(22px, calc((100vw - var(--max)) / 2));
}

.studio-section {
  background: #f6faf7;
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(220px, 420px) minmax(0, 1fr);
  gap: 40px;
  align-items: end;
  margin-bottom: 42px;
}

.section-heading.narrow {
  display: block;
  max-width: 760px;
}

.studio-grid,
.feature-grid,
.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.studio-grid article,
.feature-card,
.steps article {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 24px;
}

.studio-grid article {
  min-height: 230px;
}

.number {
  color: var(--amber);
  font-size: 13px;
  font-weight: 900;
}

.studio-grid h3,
.feature-card h3,
.steps h3,
.timeline h3 {
  margin: 14px 0 8px;
  color: var(--ink);
  font-size: 20px;
  line-height: 1.25;
}

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

.app-section {
  background: #fbfcfd;
}

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

.feature-card {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  column-gap: 18px;
  align-items: start;
}

.feature-icon {
  grid-row: span 2;
  display: inline-flex;
  width: 74px;
  height: 74px;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: #eef6fa;
  color: var(--blue-dark);
  font-size: 13px;
  font-weight: 900;
}

.feature-card:nth-child(2) .feature-icon,
.feature-card:nth-child(5) .feature-icon {
  background: #eef8f1;
  color: var(--green);
}

.feature-card:nth-child(3) .feature-icon,
.feature-card:nth-child(6) .feature-icon {
  background: #fff4df;
  color: var(--amber);
}

.feature-card h3 {
  margin-top: 0;
}

.privacy-section {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 0.75fr);
  gap: 38px;
  align-items: start;
  background: #182638;
  color: #fff;
}

.privacy-section h2,
.privacy-section p {
  color: #fff;
}

.privacy-section p {
  color: #cbd6df;
}

.principle-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.principle-list li {
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.06);
  padding: 15px 16px;
  color: #edf4f7;
  font-weight: 750;
}

.log-section {
  background: #fff;
}

.timeline {
  display: grid;
  gap: 14px;
  max-width: 860px;
}

.timeline article {
  border-left: 4px solid var(--blue);
  padding: 4px 0 20px 24px;
}

.timeline time {
  color: var(--rose);
  font-size: 13px;
  font-weight: 850;
}

.timeline h3 {
  margin-top: 6px;
}

.faq-section {
  background: #f8fafb;
}

.steps article span {
  display: inline-flex;
  width: 34px;
  height: 34px;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--blue-dark);
  color: #fff;
  font-weight: 900;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  padding: 24px max(22px, calc((100vw - var(--max)) / 2));
  background: #101821;
  color: #dbe6ed;
  font-size: 14px;
}

.site-footer a {
  color: #9de1ff;
  font-weight: 800;
}

.admin-body {
  min-height: 100vh;
  background:
    linear-gradient(135deg, rgba(75, 188, 235, 0.2), transparent 36%),
    linear-gradient(180deg, #f8fbfd 0%, #eef5f8 100%);
}

.admin-shell {
  width: min(960px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 34px 0 60px;
}

.back-link {
  display: inline-flex;
  margin-bottom: 18px;
  color: var(--blue-dark);
  font-weight: 850;
}

.admin-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 28px;
  box-shadow: var(--shadow);
}

.admin-heading {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.admin-heading h1 {
  font-size: clamp(32px, 6vw, 52px);
}

.admin-status {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 24px;
}

.admin-status div {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--mist);
  padding: 16px;
}

.admin-status span,
.upload-form label {
  display: block;
  color: var(--muted);
  font-size: 13px;
  font-weight: 850;
}

.admin-status strong {
  display: block;
  margin-top: 5px;
  overflow-wrap: anywhere;
  color: var(--ink);
  font-size: 16px;
}

.upload-form {
  display: grid;
  gap: 16px;
}

.upload-form input,
.upload-form textarea {
  width: 100%;
  margin-top: 7px;
  border: 1px solid #cfdbe3;
  border-radius: 7px;
  background: #fff;
  color: var(--ink);
  font: inherit;
  font-size: 15px;
  padding: 12px 13px;
}

.upload-form input:focus,
.upload-form textarea:focus {
  border-color: var(--cyan);
  outline: 3px solid rgba(75, 188, 235, 0.25);
}

.upload-form button {
  justify-self: start;
}

.form-message {
  min-height: 26px;
  margin: 0;
  color: var(--muted);
  font-weight: 750;
}

.form-message.is-error {
  color: #b03445;
}

.form-message.is-success {
  color: var(--green);
}

@media (max-width: 900px) {
  .site-header {
    position: static;
    align-items: flex-start;
    flex-direction: column;
  }

  .site-nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .hero,
  .download-strip,
  .section-heading,
  .privacy-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
    padding-top: 42px;
  }

  .hero-visual {
    width: min(100%, 420px);
  }

  .hero-facts,
  .studio-grid,
  .steps,
  .admin-status {
    grid-template-columns: 1fr;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 620px) {
  body {
    font-size: 15px;
  }

  .hero h1 {
    font-size: 54px;
  }

  .hero-facts,
  .download-card,
  .feature-card,
  .admin-heading {
    display: block;
  }

  .download-card .button {
    width: 100%;
    margin-top: 16px;
  }

  .feature-icon {
    margin-bottom: 16px;
  }

  .studio-section,
  .app-section,
  .privacy-section,
  .log-section,
  .faq-section {
    padding-top: 54px;
    padding-bottom: 54px;
  }

  .admin-panel {
    padding: 20px;
  }
}