/* ==========================================================================
   Layout: header, navigace, footer
   ========================================================================== */

/* ---- Header ---- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding-block: var(--space-sm);
  background: transparent;
  transition: background var(--duration-base) var(--ease-standard),
    box-shadow var(--duration-base) var(--ease-standard),
    padding-block var(--duration-base) var(--ease-standard);
}

.header.is-scrolled {
  background: var(--color-white);
  box-shadow: var(--shadow-header);
  padding-block: 0.625rem;
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.header__logo {
  display: flex;
  align-items: center;
}

.header__logo img {
  height: 34px;
  width: auto;
  transition: filter var(--duration-fast) var(--ease-standard);
  /* Přes hero fotku je logo bílé (invertované); jakmile header zbělá při scrollu, vrátí se do tmavé verze. */
  filter: brightness(0) invert(1);
}

.header.is-scrolled .header__logo img {
  filter: none;
}

.header__nav {
  display: none;
}

@media (min-width: 900px) {
  .header__nav {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
  }

  .header__nav-list {
    display: flex;
    gap: var(--space-md);
  }

  .header__nav-link {
    font-size: var(--text-small);
    font-weight: 500;
    text-decoration: none;
    color: var(--color-white);
    position: relative;
    padding-block: 0.35rem;
    transition: color var(--duration-fast) var(--ease-standard);
  }

  .header.is-scrolled .header__nav-link {
    color: var(--color-navy);
  }

  .header__nav-link::after {
    content: "";
    position: absolute;
    left: 0;
    right: 100%;
    bottom: 0;
    height: 2px;
    background: var(--color-yellow);
    transition: right var(--duration-fast) var(--ease-standard);
  }

  .header__nav-link:hover::after,
  .header__nav-link.is-active::after {
    right: 0;
  }
}

.header__cta {
  display: none;
}

@media (min-width: 900px) {
  .header__cta {
    display: inline-flex;
  }
}

.header__burger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--color-white);
  background: none;
  padding: 0;
  transition: border-color var(--duration-fast) var(--ease-standard);
}

.header.is-scrolled .header__burger {
  border-color: var(--color-navy);
}

@media (min-width: 900px) {
  .header__burger {
    display: none;
  }
}

.header__burger-bars {
  position: relative;
  width: 20px;
  height: 14px;
}

.header__burger-bars span {
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-white);
  transition: transform var(--duration-fast) var(--ease-standard),
    opacity var(--duration-fast) var(--ease-standard),
    background var(--duration-fast) var(--ease-standard);
}

.header.is-scrolled .header__burger-bars span {
  background: var(--color-navy);
}

/* Mobilní overlay je navy bez ohledu na scroll, logo i burger proto zůstanou bílé */
.header.is-nav-open .header__logo img {
  filter: brightness(0) invert(1);
}

.header.is-nav-open .header__burger {
  border-color: var(--color-white);
}

.header.is-nav-open .header__burger-bars span {
  background: var(--color-white);
}

.header__burger-bars span:nth-child(1) {
  top: 0;
}

.header__burger-bars span:nth-child(2) {
  top: 6px;
}

.header__burger-bars span:nth-child(3) {
  top: 12px;
}

.header__burger[aria-expanded="true"] .header__burger-bars span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.header__burger[aria-expanded="true"] .header__burger-bars span:nth-child(2) {
  opacity: 0;
}

.header__burger[aria-expanded="true"] .header__burger-bars span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* ---- Mobile overlay ---- */
.mobile-nav {
  position: fixed;
  inset: 0;
  z-index: 90;
  background: var(--color-navy);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: var(--space-lg);
  padding: var(--container-pad);
  transform: translateY(-100%);
  transition: transform var(--duration-base) var(--ease-standard);
}

.mobile-nav.is-open {
  transform: translateY(0);
}

.mobile-nav__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.mobile-nav__link {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  color: var(--color-white);
  text-decoration: none;
}

.mobile-nav__cta {
  margin-top: var(--space-sm);
}

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

/* ---- Footer ---- */
.footer {
  background-color: var(--color-navy);
  background-image: repeating-linear-gradient(
    100deg,
    rgba(255, 255, 255, 0.035) 0 1px,
    transparent 1px 3px
  );
  color: var(--color-white);
  padding-block: var(--space-2xl) var(--space-lg);
}

.footer__grid {
  display: grid;
  gap: var(--space-lg);
  grid-template-columns: 1fr;
}

@media (min-width: 700px) {
  .footer__grid {
    grid-template-columns: 1.3fr 1fr 1fr;
  }
}

.footer__logo img {
  height: 30px;
  width: auto;
  filter: brightness(0) invert(1);
}

.footer__ico {
  margin-top: var(--space-sm);
  font-size: var(--text-small);
  color: var(--color-grey-light);
}

.footer__heading {
  font-family: var(--font-heading);
  font-size: var(--text-small);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-grey-light);
  margin-bottom: var(--space-sm);
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer__list a {
  color: var(--color-white);
  text-decoration: none;
  font-size: var(--text-small);
}

.footer__list a:hover {
  color: var(--color-yellow);
}

.footer__bottom {
  margin-top: var(--space-xl);
  padding-top: var(--space-md);
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  justify-content: space-between;
  font-size: var(--text-small);
  color: var(--color-grey-light);
}

.footer__credit {
  font-size: 0.75rem;
  color: var(--color-grey-light);
  opacity: 0.7;
}

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

.footer__credit a:hover {
  color: var(--color-yellow);
}