/*=============== GOOGLE FONTS ===============*/
@import url("https://fonts.googleapis.com/css2?family=Montserrat+Alternates:wght@400;600;700&display=swap");

/*=============== VARIABLES CSS ===============*/
:root {
  /*========== Colors ==========*/
  --first-color: hsl(225, 95%, 56%);
  --black-color: hsl(225, 12%, 12%);
  --white-color: hsl(0, 0%, 100%);
  --text-color: #00000087;
  --body-color: hsl(225, 100%, 99%);
  --glass-color: rgba(255, 255, 255, 0.1);

  /*========== Font and typography ==========*/
  --body-font: "Montserrat Alternates", sans-serif;
  --biggest-font-size: 2.5rem;
  --tiny-font-size: .625rem;

  /*========== Font weight ==========*/
  --font-regular: 400;
  --font-semi-bold: 600;
  --font-bold: 700;

  /*========== z index ==========*/
  --z-tooltip: 10;
  --z-fixed: 100;
}

/*=============== BASE ===============*/
* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--body-font);
  background-color: var(--body-color);
}

ul {
  list-style: none;
}

a {
  text-decoration: none;
}

/*=============== POSUNUTÝ WRAPPER (Centrování) ===============*/
.nav-floating-wrapper {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 12px;
  /* Mezera mezi bublinou a barem */
  z-index: var(--z-fixed);
  width: max-content;
  /* Zabrání roztažení na celou šířku */
}

/*=============== BUBILNA ZPĚT ===============*/
.back-bubble {
  width: 54px;
  height: 54px;
  background-color: var(--glass-color);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-color);
  font-size: 1.5rem;
  box-shadow: 0 2px 16px hsla(228, 95%, 4%, 0.1);
  transition: color .4s, transform .4s;
  padding: 0;
  outline: none;
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.back-bubble:hover {
  color: var(--black-color);
  transform: scale(1.05);
}

.back-bubble--disabled {
  opacity: 0.2;
  cursor: default;
  pointer-events: none;
}

/*=============== NAVBAR ===============*/
.nav {
  /* DŮLEŽITÉ: Není zde position fixed ani width 88% */
  background-color: var(--glass-color);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 2px 16px hsla(228, 95%, 4%, 0.1);
  padding: 1rem 1.75rem;
  border-radius: 4rem;
  border: 1px solid rgba(255, 255, 255, 0.3);
  width: 280px;
  /* Šířka pro mobily */
}

.nav__list {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav__link {
  color: var(--text-color);
  font-size: 1.5rem;
  transition: color .4s;
  display: flex;
}

.nav__link:hover {
  color: var(--black-color);
}

.active-link {
  color: var(--black-color);
}

/*=============== RESPONSIVE ===============*/
@media screen and (min-width: 450px) {
  .nav {
    width: 350px;
    /* Šířka pro větší mobily/tablety */
  }
}

@media screen and (min-width: 1150px) {
  :root {
    --biggest-font-size: 3.5rem;
  }
}

/*=============== REUSABLE CLASSES ===============*/
.container {
  max-width: 1120px;
  margin-inline: 1.5rem;
  margin-inline: auto;
}

.section {
  height: 100vh;
  padding-block: 2.5rem;
}

.section h1 {
  font-size: var(--biggest-font-size);
  color: var(--black-color);
  text-align: center;
}