.oo-header,
.oo-section,
.oo-footer {
  box-sizing: border-box;
  width: 100%;
  font-family: "proxima-nova", Arial, sans-serif;
}

.oo-header *,
.oo-section *,
.oo-footer * {
  box-sizing: border-box;
}

.oo-header {
  position: relative;
  z-index: 5;
  padding: 20px 24px;
  background: #fff;
}

.oo-header__inner {
  width: 100%;
  max-width: 1320px;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.oo-header__logo {
  display: block;
  flex: 0 1 auto;
  line-height: 0;
}

.oo-header__logo img {
  display: block;
  width: 270px;
  max-width: 100%;
  height: auto;
}

.oo-header__nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
}

.oo-header__nav a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 11px 18px;
  border-radius: 4px;
  background: #f6f6f6;
  color: #35465d;
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  transition: color 180ms ease, background-color 180ms ease, transform 180ms ease;
}

.oo-header__nav a:hover,
.oo-header__nav a:focus-visible {
  transform: translateY(-1px);
  background: #00a8fe;
  color: #fff;
}

.oo-section {
  padding: 76px 24px;
  color: #35465d;
}

.oo-section__inner {
  width: 100%;
  max-width: 1180px;
  margin-inline: auto;
}

.oo-section__heading {
  margin: 0 0 28px;
}

.oo-section__heading--center {
  text-align: center;
}

.oo-section__heading h1,
.oo-section__heading h2,
.oo-section__heading h3,
.oo-section__heading h4,
.oo-section__heading div {
  margin: 0;
  color: #343434;
  font-family: "proxima-nova", Arial, sans-serif;
  font-size: clamp(30px, 3vw, 45px);
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: -0.02em;
}

.oo-section__accent {
  display: block;
  width: 58px;
  height: 3px;
  margin-top: 18px;
  background: #00a8fe;
}

.oo-section__heading--center .oo-section__accent {
  margin-inline: auto;
}

.oo-course-use {
  background: #f6f6f6;
}

.oo-course-use__intro {
  max-width: 860px;
  margin: 0 auto 42px;
  color: #35465d;
  font-size: 18px;
  line-height: 1.62;
  text-align: center;
}

.oo-course-use__intro p {
  margin: 0;
}

.oo-course-use__grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.oo-guidance-card {
  position: relative;
  min-width: 0;
  padding: 30px 28px;
  border-radius: 8px;
  background: #fff;
  color: #35465d;
  box-shadow: 0 14px 36px rgba(53, 70, 93, 0.08);
}

.oo-guidance-card__mark {
  display: block;
  width: 14px;
  height: 14px;
  margin-bottom: 20px;
  border-radius: 50%;
  background: #ffcd5c;
}

.oo-guidance-card__text {
  font-size: 17px;
  font-weight: 500;
  line-height: 1.48;
}

.oo-competencies {
  background: #fff;
}

.oo-development {
  background: #f6f6f6;
}

.oo-reading-grid {
  --oo-heading-column: 38%;
  display: grid;
  grid-template-columns: minmax(0, var(--oo-heading-column)) minmax(0, 1fr);
  align-items: start;
  gap: 70px;
}

.oo-prose {
  min-width: 0;
  color: #35465d;
  font-size: 17px;
  line-height: 1.65;
}

.oo-prose p {
  margin: 0 0 20px;
}

.oo-prose p:last-child {
  margin-bottom: 0;
}

.oo-prose a {
  color: #007dbe;
  overflow-wrap: anywhere;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 180ms ease;
}

.oo-prose a:hover,
.oo-prose a:focus-visible {
  color: #ef705d;
}

.oo-development__image {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  margin-top: 24px;
  border-radius: 8px;
}

.oo-footer {
  padding: 58px 24px 28px;
  background: #35465d;
  color: #fff;
}

.oo-footer__inner {
  width: 100%;
  max-width: 1180px;
  margin-inline: auto;
}

.oo-footer__resources {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 13px 36px;
}

.oo-footer a {
  color: #fff;
  font-size: 16px;
  line-height: 1.42;
  overflow-wrap: anywhere;
  text-decoration: none;
  transition: color 180ms ease;
}

.oo-footer a:hover,
.oo-footer a:focus-visible {
  color: #00ceff;
}

.oo-footer__legal {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  margin-top: 38px;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.22);
}

.oo-footer__copyright {
  margin: 24px 0 0;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.22);
  color: #d9f2ff;
  font-size: 14px;
  line-height: 1.4;
}

@media (max-width: 1024px) {
  .oo-section {
    padding: 58px 24px;
  }

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

  .oo-reading-grid {
    gap: 42px;
  }
}

@media (max-width: 767px) {
  .oo-header {
    padding: 16px 18px;
  }

  .oo-header--stack-mobile .oo-header__inner {
    flex-direction: column;
    align-items: stretch;
    gap: 18px;
  }

  .oo-header--stack-mobile .oo-header__logo {
    align-self: center;
  }

  .oo-header__logo img {
    width: 190px;
  }

  .oo-header__nav {
    justify-content: center;
  }

  .oo-header--stack-mobile .oo-header__nav a {
    flex: 1 1 auto;
  }

  .oo-section {
    padding: 44px 18px;
  }

  .oo-section__heading h1,
  .oo-section__heading h2,
  .oo-section__heading h3,
  .oo-section__heading h4,
  .oo-section__heading div {
    font-size: clamp(28px, 9vw, 38px);
  }

  .oo-course-use__intro {
    margin-bottom: 30px;
    font-size: 17px;
    text-align: left;
  }

  .oo-course-use__grid,
  .oo-reading-grid,
  .oo-footer__resources {
    grid-template-columns: minmax(0, 1fr);
  }

  .oo-reading-grid {
    gap: 10px;
  }

  .oo-guidance-card {
    padding: 26px 24px;
  }

  .oo-prose {
    font-size: 16px;
  }

  .oo-development__image {
    margin-bottom: 24px;
  }

  .oo-footer {
    padding: 42px 18px 24px;
  }
}

@media (max-width: 420px) {
  .oo-header__nav {
    gap: 8px;
  }

  .oo-header__nav a {
    min-height: 40px;
    padding: 10px 13px;
    font-size: 14px;
  }
}