html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  background: #ffffff;
  color: #1d1d1f;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

* {
  box-sizing: border-box;
}

.si-container {
  width: 100%;
  max-width: 1440px;
  margin: 0 auto;
  padding-left: 44px;
  padding-right: 44px;
}

.si-header {
  width: 100%;
  background: #fbfbfd;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.si-header-top {
  background: #f5f5f7;
}

.si-header-divider {
  width: 100%;
  height: 1px;
  background: #dcdcdf;
}

.si-header-inner {
  min-height: 78px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

/* Logo */
.si-logo {
  display: flex;
  flex-direction: column;
  justify-content: center;
  text-decoration: none;
  color: #1d1d1f;
  flex-shrink: 0;
  line-height: 1;
}

.si-logo-title {
  font-size: 21px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: #111111;
  line-height: 1;
}

.si-logo-subtitle {
  margin-top: 7px;
  font-size: 10px;
  font-weight: 600;
  line-height: 1.2;
  color: #00488F;
  letter-spacing: -0.01em;
  opacity: 0.92;
}

/* Nav */
.si-nav {
  flex: 1;
  display: flex;
  justify-content: center;
  min-width: 0;
}

.si-nav-list {
  display: flex;
  align-items: center;
  gap: 38px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.si-nav-list li {
  margin: 0;
  padding: 0;
}

.si-nav-list a {
  text-decoration: none;
  color: #1d1d1f;
  font-size: 13px;
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.01em;
  transition: color 0.2s ease;
  white-space: nowrap;
}

.si-nav-list a:hover {
  color: #00488F;
}

/* Right side */
.si-auth {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-shrink: 0;
}

.si-login {
  text-decoration: none;
  color: #00488F;
  font-size: 13px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.01em;
  transition: color 0.2s ease;
  white-space: nowrap;
}

.si-login:hover {
  color: #00376c;
}

.si-register {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 18px;
  border-radius: 999px;
  background: #00488F;
  color: #ffffff;
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.01em;
  white-space: nowrap;
  transition: background 0.2s ease;
}

.si-register:hover {
  background: #003d79;
}

/* Desktop narrow */
@media (max-width: 1200px) {
  .si-container {
    padding-left: 28px;
    padding-right: 28px;
  }

  .si-nav-list {
    gap: 26px;
  }

  .si-logo-title {
    font-size: 23px;
  }
}

/* Tablet */
@media (max-width: 900px) {
  .si-header-inner {
    min-height: auto;
    padding-top: 14px;
    padding-bottom: 14px;
    flex-wrap: wrap;
    gap: 14px;
  }

  .si-logo {
    width: auto;
    max-width: 100%;
  }

  .si-logo-title {
    font-size: 22px;
  }

  .si-logo-subtitle {
    font-size: 9px;
    margin-top: 5px;
  }

  .si-auth {
    margin-left: auto;
    gap: 12px;
  }

  .si-login,
  .si-register {
    font-size: 12px;
  }

  .si-register {
    min-height: 36px;
    padding: 0 14px;
  }

  .si-nav {
    order: 3;
    width: 100%;
    justify-content: flex-start;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .si-nav::-webkit-scrollbar {
    display: none;
  }

  .si-nav-list {
    gap: 20px;
    flex-wrap: nowrap;
    min-width: max-content;
    padding-bottom: 2px;
  }
}

/* Mobile */
@media (max-width: 640px) {
  .si-container {
    padding-left: 16px;
    padding-right: 16px;
  }

  .si-header-inner {
    display: grid;
    grid-template-columns: 1fr auto;
    grid-template-areas:
      "logo auth"
      "nav nav";
    align-items: center;
    gap: 14px 12px;
    padding-top: 14px;
    padding-bottom: 12px;
  }

  .si-logo {
    grid-area: logo;
    min-width: 0;
  }

  .si-logo-title {
    font-size: 20px;
    line-height: 0.95;
  }

  .si-logo-subtitle {
    font-size: 8.5px;
    margin-top: 5px;
    line-height: 1.15;
  }

  .si-auth {
    grid-area: auth;
    margin-left: 0;
    justify-content: flex-end;
    gap: 10px;
  }

  .si-login {
    font-size: 11px;
  }

  .si-register {
    min-height: 34px;
    padding: 0 13px;
    font-size: 11px;
  }

  .si-nav {
    grid-area: nav;
    width: 100%;
    justify-content: flex-start;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .si-nav-list {
    gap: 18px;
    padding-bottom: 2px;
  }

  .si-nav-list a {
    font-size: 12px;
  }
}

/* Small mobile */
@media (max-width: 420px) {
  .si-header-inner {
    gap: 12px 10px;
  }

  .si-logo-title {
    font-size: 18px;
  }

  .si-logo-subtitle {
    font-size: 8px;
  }

  .si-auth {
    gap: 8px;
  }

  .si-login {
    font-size: 10.5px;
  }

  .si-register {
    min-height: 32px;
    padding: 0 11px;
    font-size: 10.5px;
  }

  .si-nav-list {
    gap: 16px;
  }

  .si-nav-list a {
    font-size: 11.5px;
  }
}