.rk-header {
  --rk-header-text-strong: #eef6fb;
  --rk-header-text-soft: rgba(226, 239, 246, 0.78);
  --rk-header-text-muted: rgba(226, 239, 246, 0.55);
  --rk-header-winter-deep: #9cc5da;
  --rk-header-ink: #0b1d2a;
  --rk-header-snow: rgba(10, 24, 36, 0.95);
  --rk-header-shadow: 0 18px 40px rgba(5, 10, 15, 0.55);
  position: sticky;
  top: 0;
  z-index: 1000;
  overflow: visible;
  padding-top: env(safe-area-inset-top);
  background: linear-gradient(90deg, rgba(12, 28, 42, 0.98) 0%, rgba(18, 38, 54, 0.96) 50%, rgba(12, 28, 42, 0.98) 100%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 12px 34px rgba(4, 8, 12, 0.6);
}

.rk-header::before,
.rk-header::after {
  content: none;
}

body.rk-nav-open {
  overflow: hidden;
}

.rk-snowfield {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 120vh;
  pointer-events: none;
  overflow: hidden;
  z-index: 1100;
}

.rk-snowflake {
  position: absolute;
  top: -24px;
  color: rgba(255, 255, 255, 0.92);
  opacity: 0;
  text-shadow: 0 0 10px rgba(255, 255, 255, 0.6);
  animation-name: rk-snowflake-fall;
  animation-timing-function: linear;
  animation-fill-mode: forwards;
  will-change: transform, opacity;
}

.rk-header .rk-top-bar,
.rk-header .rk-main-bar {
  position: relative;
  z-index: 1;
}

.rk-top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 6px 20px 4px;
  font-size: 0.62rem;
  text-transform: uppercase;
  letter-spacing: 0.28em;
  color: var(--rk-header-text-muted);
}

.rk-utility-links {
  display: flex;
  align-items: center;
  gap: 16px;
}

.rk-utility-links a {
  transition: color 0.2s ease;
}

.rk-utility-links a:hover {
  color: var(--rk-header-winter-deep);
}

.rk-search {
  display: flex;
  align-items: center;
  gap: 6px;
}

.rk-search input {
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  padding: 4px 12px;
  font-size: 0.7rem;
  width: min(240px, 42vw);
  background: rgba(255, 255, 255, 0.92);
  color: var(--rk-header-ink);
}

.rk-search button {
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 4px 10px;
  font-size: 0.64rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  background: rgba(226, 239, 246, 0.18);
  color: var(--rk-header-text-strong);
  cursor: pointer;
  transition: transform 0.2s ease, background 0.2s ease;
}

.rk-search button:hover {
  background: rgba(226, 239, 246, 0.28);
  transform: translateY(-1px);
}

.rk-nav-search {
  display: none;
}

.rk-nav-utility {
  display: none;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
}

.rk-nav-utility a {
  font-size: 0.62rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--rk-header-text-muted);
}

.rk-nav-utility a:hover {
  color: var(--rk-header-text-strong);
}

.rk-main-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 20px 12px;
}

.rk-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: "CalSans", "Rubik", sans-serif;
  color: var(--rk-header-text-strong);
}

.rk-logo img {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  box-shadow: 0 8px 16px rgba(35, 56, 70, 0.15);
}

.rk-logo span {
  font-size: 1.4rem;
  letter-spacing: 0.02em;
}

.rk-nav-toggle {
  display: none;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 999px;
  align-items: center;
  justify-content: center;
  padding: 6px 14px;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--rk-header-text-strong);
  cursor: pointer;
  line-height: 1;
  text-align: center;
}

.rk-nav {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-left: 6px;
}

.rk-nav a,
.rk-nav summary {
  display: inline-flex;
  align-items: center;
  font-size: 0.72rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--rk-header-text-soft);
  cursor: pointer;
  transition: color 0.2s ease;
  white-space: nowrap;
}

.rk-nav > a,
.rk-nav > details {
  flex: 0 0 auto;
}

.rk-nav-item {
  position: relative;
  padding-right: 18px;
}

.rk-nav-item::after {
  content: "|";
  position: absolute;
  right: 6px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--rk-header-text-muted);
  font-size: 0.8rem;
}

.rk-nav-item-last::after {
  content: "";
}

.rk-nav a:hover,
.rk-nav summary:hover {
  color: var(--rk-header-text-strong);
}

.rk-nav > a.is-active,
.rk-nav > details > summary.is-active {
  color: var(--rk-header-text-strong);
  text-decoration: underline;
  text-decoration-color: var(--rk-header-winter-deep);
  text-decoration-thickness: 2px;
  text-underline-offset: 6px;
}

.rk-nav details {
  position: relative;
}

.rk-nav summary {
  list-style: none;
}

.rk-nav summary::-webkit-details-marker {
  display: none;
}

.rk-dropdown {
  position: absolute;
  top: calc(100% + 14px);
  left: 0;
  min-width: 220px;
  background: var(--rk-header-snow);
  border-radius: 16px;
  padding: 12px;
  box-shadow: var(--rk-header-shadow);
  opacity: 0;
  transform: translateY(-6px);
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 2000;
}

.rk-dropdown a {
  display: grid;
  grid-template-columns: 36px 1fr;
  grid-template-rows: auto auto;
  column-gap: 12px;
  row-gap: 2px;
  align-items: center;
  padding: 10px 12px;
  border-radius: 10px;
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  background: rgba(18, 38, 54, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 10px 22px rgba(4, 8, 12, 0.5);
}

.rk-dropdown img {
  grid-row: 1 / span 2;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  padding: 0;
  background: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 6px 12px rgba(4, 8, 12, 0.4);
  object-fit: cover;
}

.rk-dropdown-item span {
  line-height: 1.2;
}

.rk-dropdown-title {
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--rk-header-text-strong);
}

.rk-dropdown-desc {
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  text-transform: none;
  color: var(--rk-header-text-muted);
}

.rk-dropdown a:hover {
  background: rgba(255, 255, 255, 0.1);
}

.rk-dropdown a.is-active {
  background: rgba(156, 197, 218, 0.2);
  border-color: rgba(156, 197, 218, 0.6);
  color: var(--rk-header-text-strong);
  text-decoration: none;
}

.rk-dropdown a.is-active .rk-dropdown-desc {
  color: rgba(226, 239, 246, 0.78);
}

.rk-nav details[open] .rk-dropdown {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

@media (hover: hover) {
  .rk-nav details:hover .rk-dropdown {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
  }
}

.rk-cta {
  padding: 8px 16px;
  border-radius: 999px;
  background: rgba(156, 197, 218, 0.28);
  color: var(--rk-header-text-strong);
  letter-spacing: 0.2em;
  transition: transform 0.2s ease, background 0.2s ease;
  white-space: nowrap;
}

.rk-cta:hover {
  background: rgba(156, 197, 218, 0.45);
  transform: translateY(-1px);
}

.rk-header.is-scrolled .rk-top-bar {
  padding-top: 4px;
  padding-bottom: 2px;
}

.rk-header.is-scrolled .rk-main-bar {
  padding-bottom: 8px;
}

.rk-header.is-scrolled .rk-logo img {
  width: 46px;
  height: 46px;
}

.rk-landing .rk-top-bar {
  display: none;
}

.rk-landing .rk-nav,
.rk-landing .rk-nav-toggle {
  display: none;
}

.rk-landing .rk-main-bar {
  padding: 10px 20px;
}

@keyframes rk-snowflake-fall {
  0% {
    transform: translate3d(var(--drift, 0px), 0, 0);
    opacity: 0;
  }
  10% {
    opacity: 1;
  }
  100% {
    transform: translate3d(var(--drift, 0px), 220%, 0);
    opacity: 0;
  }
}

@media (max-width: 1200px) {
  .rk-main-bar {
    gap: 6px;
  }

  .rk-logo {
    gap: 8px;
  }

  .rk-logo img {
    width: 48px;
    height: 48px;
  }

  .rk-logo span {
    font-size: 1.25rem;
  }

  .rk-nav {
    gap: 12px;
    margin-left: 4px;
  }

  .rk-nav a,
  .rk-nav summary {
    font-size: 0.68rem;
    letter-spacing: 0.18em;
  }

  .rk-nav-item {
    padding-right: 12px;
  }

  .rk-nav-item::after {
    right: 4px;
  }

  .rk-cta {
    padding: 7px 12px;
    font-size: 0.66rem;
    letter-spacing: 0.18em;
  }
}

@media (max-width: 1080px) {
  .rk-nav {
    gap: 10px;
  }

  .rk-nav a,
  .rk-nav summary {
    font-size: 0.64rem;
    letter-spacing: 0.14em;
  }

  .rk-nav-item {
    padding-right: 0;
  }

  .rk-nav-item::after {
    content: none;
  }

  .rk-cta {
    padding: 6px 10px;
    font-size: 0.62rem;
    letter-spacing: 0.14em;
  }
}

@media (max-width: 900px) {
  .rk-top-bar {
    display: none;
  }

  .rk-search {
    width: 100%;
    justify-content: center;
  }

  .rk-main-bar {
    flex-wrap: wrap;
  }

  .rk-nav-toggle {
    display: inline-flex;
    margin-left: auto;
    min-height: 44px;
    padding: 10px 16px;
  }

  .rk-nav {
    display: none;
    flex-direction: column;
    align-items: center;
    width: 100%;
    background: rgba(7, 18, 26, 0.94);
    border-radius: 0 0 20px 20px;
    padding: 12px 20px 24px;
    box-shadow: var(--rk-header-shadow);
    position: fixed;
    left: 0;
    right: 0;
    top: var(--rk-header-height, 72px);
    height: calc(100dvh - var(--rk-header-height, 72px));
    margin: 0;
    gap: 12px;
    overflow-y: auto;
    overscroll-behavior: contain;
    -webkit-overflow-scrolling: touch;
    backdrop-filter: blur(16px) saturate(120%);
    -webkit-backdrop-filter: blur(16px) saturate(120%);
    padding-bottom: calc(18px + env(safe-area-inset-bottom));
  }

  .rk-nav.is-open {
    display: flex;
  }

  .rk-nav details,
  .rk-nav a {
    width: 100%;
  }

  .rk-nav > a,
  .rk-nav > details {
    padding: 0;
    order: 2;
  }

  .rk-nav a,
  .rk-nav summary {
    font-size: 0.72rem;
    letter-spacing: 0.12em;
  }

  .rk-nav > a,
  .rk-nav > details > summary {
    display: flex;
    align-items: center;
    min-height: 44px;
    padding: 6px 0;
    justify-content: center;
    text-align: center;
  }

  .rk-nav summary {
    position: relative;
    padding-left: 26px;
    padding-right: 26px;
  }

  .rk-nav summary::after {
    content: "";
    position: absolute;
    right: 12px;
    top: 50%;
    width: 7px;
    height: 7px;
    border-right: 2px solid rgba(226, 239, 246, 0.6);
    border-bottom: 2px solid rgba(226, 239, 246, 0.6);
    transform: translateY(-50%) rotate(45deg);
    transition: transform 0.2s ease, border-color 0.2s ease;
  }

  .rk-nav details[open] > summary::after {
    transform: translateY(-50%) rotate(-135deg);
    border-color: rgba(226, 239, 246, 0.85);
  }

  .rk-nav-item {
    padding-right: 0;
  }

  .rk-nav-item-last {
    display: none;
  }

  .rk-nav-item::after {
    content: none;
  }

  .rk-dropdown {
    position: static;
    opacity: 1;
    transform: none;
    pointer-events: auto;
    box-shadow: none;
    background: transparent;
    padding: 6px 0 0;
    width: min(100%, 420px);
    margin: 0 auto;
  }

  .rk-dropdown a {
    min-height: 44px;
    grid-template-columns: 28px 1fr;
    column-gap: 10px;
    row-gap: 2px;
    padding: 8px 0;
    background: transparent;
    border: none;
    box-shadow: none;
    letter-spacing: 0.12em;
  }

  .rk-dropdown img {
    width: 28px;
    height: 28px;
    border-radius: 8px;
    box-shadow: none;
  }

  .rk-dropdown-title {
    font-size: 0.68rem;
    letter-spacing: 0.14em;
  }

  .rk-dropdown-desc {
    font-size: 0.6rem;
    letter-spacing: 0.06em;
  }

  .rk-nav-search {
    display: flex;
    width: 100%;
    max-width: 420px;
    margin-top: 0;
    margin-bottom: 6px;
    gap: 8px;
    order: 0;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
  }

  .rk-nav-search input {
    width: auto;
    flex: 1 1 200px;
    min-width: 160px;
    font-size: 0.78rem;
    padding: 8px 12px;
    min-height: 38px;
  }

  .rk-nav-search button {
    width: auto;
    padding: 8px 14px;
    font-size: 0.58rem;
    letter-spacing: 0.14em;
    flex: 0 0 auto;
    min-height: 38px;
  }

  .rk-nav-utility {
    display: flex;
    width: 100%;
    gap: 0;
    margin-top: 8px;
    order: 4;
    justify-content: center;
    flex-wrap: nowrap;
  }

  .rk-nav-utility a {
    min-height: 36px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 4px 8px;
    font-size: 0.56rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--rk-header-text-muted);
  }

  .rk-nav-utility a + a {
    margin-left: 10px;
    padding-left: 14px;
    border-left: 1px solid rgba(226, 239, 246, 0.2);
  }

  .rk-cta {
    align-self: stretch;
    text-align: center;
    order: 3;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    letter-spacing: 0.16em;
  }
}

@media (max-width: 720px) {
  .rk-top-bar {
    padding: 8px 16px 6px;
    gap: 8px;
    font-size: 0.58rem;
    letter-spacing: 0.18em;
  }

  .rk-utility-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
  }

  .rk-search {
    flex-wrap: wrap;
    gap: 8px;
  }

  .rk-search input {
    width: min(100%, 280px);
  }

  .rk-nav-search {
    max-width: 360px;
  }

  .rk-nav-search input {
    min-width: 140px;
  }

  .rk-main-bar {
    padding: 8px 16px 12px;
  }

  .rk-logo img {
    width: 44px;
    height: 44px;
  }

  .rk-logo span {
    font-size: 1.15rem;
  }
}