:root {
  --intro-navy: #12233f;
  --intro-blue: #155eef;
  --intro-blue-dark: #124fd1;
  --intro-bg: #f4f6f8;
  --intro-panel: #ffffff;
  --intro-text: #17243a;
  --intro-muted: #607087;
  --intro-line: #dce4ec;
  --intro-soft-blue: #edf4ff;
  --intro-warning-bg: #fff4f1;
  --intro-warning-line: #f0b9ad;
  --intro-warning-text: #7f2e25;
  --intro-shadow: 0 18px 44px rgba(19, 42, 72, .12);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--intro-bg);
  color: var(--intro-text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
  margin: 0;
}

a { color: inherit; }

.intro-shell {
  margin: 24px auto;
  max-width: 1160px;
  width: min(1160px, calc(100% - 32px));
}

.intro-safetybar {
  align-items: center;
  background: var(--intro-navy);
  border-radius: 14px 14px 0 0;
  color: #fff;
  display: flex;
  gap: 18px;
  justify-content: space-between;
  min-height: 64px;
  padding: 10px 20px;
}

.intro-safetybar strong,
.intro-safetybar small { display: block; }
.intro-safetybar strong { font-size: 15px; }
.intro-safetybar small { color: #c9d7e8; font-size: 13px; }

.intro-actions { display: flex; flex: 0 0 auto; gap: 10px; }

.intro-action,
.button {
  align-items: center;
  background: var(--intro-blue);
  border: 1px solid var(--intro-blue);
  border-radius: 9px;
  color: #fff;
  display: inline-flex;
  font-weight: 780;
  justify-content: center;
  min-height: 38px;
  padding: 7px 12px;
  text-decoration: none;
}

.intro-action--secondary {
  background: #fff;
  border-color: #dce4ec;
  color: var(--intro-navy);
}

.intro-action:hover,
.button:hover { background: var(--intro-blue-dark); }
.intro-action--secondary:hover { background: #edf3f9; }

.intro-action:focus-visible,
.button:focus-visible,
.back-link:focus-visible {
  outline: 3px solid #8ab4ff;
  outline-offset: 3px;
}

.intro-canvas {
  background: var(--intro-bg);
  border: 1px solid var(--intro-line);
  border-radius: 0 0 14px 14px;
  box-shadow: var(--intro-shadow);
  overflow: hidden;
}

.intro-window-bar {
  align-items: center;
  background: #e8edf2;
  border-bottom: 1px solid #d5dde6;
  display: flex;
  gap: 7px;
  min-height: 38px;
  padding: 8px 14px;
}

.intro-window-bar span {
  background: #a4b0be;
  border-radius: 50%;
  height: 10px;
  width: 10px;
}

.intro-window-bar p {
  color: #64748b;
  font-size: 12px;
  margin: 0 0 0 8px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.intro-content {
  background: var(--intro-panel);
  padding: clamp(24px, 5vw, 50px);
}

.back-link {
  color: #244d81;
  display: inline-flex;
  font-size: 14px;
  font-weight: 750;
  margin-bottom: 28px;
  text-decoration: none;
}

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

.kicker {
  color: #155eef;
  font-size: 13px;
  font-weight: 850;
  letter-spacing: .08em;
  margin: 0 0 7px;
  text-transform: uppercase;
}

h1, h2 { color: var(--intro-text); }

h1 {
  font-size: clamp(30px, 4vw, 46px);
  letter-spacing: -.035em;
  line-height: 1.1;
  margin: 0 0 14px;
  max-width: 760px;
}

h2 { font-size: 21px; line-height: 1.25; margin: 0 0 10px; }

.lead { color: var(--intro-muted); font-size: 18px; margin: 0; max-width: 760px; }

.notice {
  background: var(--intro-warning-bg);
  border: 1px solid var(--intro-warning-line);
  border-radius: 11px;
  color: var(--intro-warning-text);
  margin: 26px 0;
  padding: 15px 16px;
}

.content-grid {
  display: grid;
  gap: 28px;
  grid-template-columns: minmax(0, 1.35fr) minmax(270px, .65fr);
}

p { margin: 0 0 14px; }
ul { margin: 0; padding-left: 21px; }
li { margin-bottom: 9px; }

.tip-card,
.preview {
  border: 1px solid var(--intro-line);
  border-radius: 12px;
  padding: 20px;
}

.tip-card { background: var(--intro-soft-blue); align-self: start; }
.preview { background: #f8fbff; margin-top: 22px; }

.preview-media { margin: 22px 0 0; }
.preview-media img { border: 1px solid var(--intro-line); border-radius: 12px; display: block; height: auto; max-width: 100%; }
.button { margin-top: 8px; min-height: 43px; padding: 10px 16px; }

@media (max-width: 760px) {
  .intro-shell { margin: 0; width: 100%; }
  .intro-safetybar { align-items: stretch; border-radius: 0; flex-direction: column; gap: 11px; padding: 13px 16px; }
  .intro-actions { width: 100%; }
  .intro-action { flex: 1 1 0; text-align: center; }
  .intro-canvas { border-left: 0; border-radius: 0; border-right: 0; box-shadow: none; }
  .intro-content { padding: 24px 18px 32px; }
  .content-grid { grid-template-columns: 1fr; }
}