/* =====================================================
   CSS VARIABLES
===================================================== */
:root {
  --primary: #0f2a44;
  --secondary: #1f5fa8;
  --background: #f4f6f9;
  --text: #111827;
  --white: #ffffff;

  --radius: 8px;
  --shadow: 0 6px 18px rgba(0,0,0,.08);
  --font: 'Inter', system-ui, sans-serif;
}

/* =====================================================
   RESET / BASE
===================================================== */
*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--background);
  color: var(--text);
  line-height: 1.65;
}

/* globální reset odkazu – přepisuje se kontextově */
a {
  color: inherit;
  text-decoration: none;
}

a:focus-visible {
  outline: 3px solid var(--secondary);
  outline-offset: 2px;
}

/* =====================================================
   LAYOUT
===================================================== */
.container {
  max-width: 1340px;
  margin: 0 auto;
  padding: 0 24px;
}

/* =====================================================
   HEADER
===================================================== */
.header {
  background: var(--white);
  box-shadow: var(--shadow);
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 0;
}

.logo img {
  height: 68px;
}

/* =====================================================
   SOCIAL LINK
===================================================== */
.social-link {
  display: flex;
  align-items: center;
  gap: 10px;
  background: #1877f2;
  color: var(--white);
  padding: 12px 18px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 14px;
}

.social-link i {
  font-size: 18px;
}

/* =====================================================
   NAVIGATION
===================================================== */
.main-nav {
  background: var(--primary);
  position: relative; /* Důležité pro absolutní pozicování mobilního menu */
  z-index: 50;
}

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

/* Tlačítko hamburgeru skryté na počítači */
.menu-toggle {
  display: none; 
  background: none;
  border: none;
  color: var(--white);
  font-size: 24px;
  padding: 16px 0;
  cursor: pointer;
}

.nav-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: row;
}

.nav-links li {
  position: relative;
}

.nav-links a {
  display: block;
  padding: 16px 18px;
  color: var(--white);
  font-weight: 500;
  transition: background 0.2s ease;
}

.nav-links a:hover,
.nav-links a:focus {
  background: rgba(255, 255, 255, 0.12);
}

/* ACTIVE PAGE */
.nav-links li > a[aria-current="page"] {
  background-color: var(--secondary);
  color: var(--white);
  border-radius: 6px;
}

/* SUBMENU */
.submenu {
  position: absolute;
  top: 100%;
  left: 0;
  background: var(--white);
  min-width: 220px;
  display: none;
  box-shadow: var(--shadow);
  z-index: 10;
  padding: 0;
  margin: 0;
  list-style: none;
}

.dropdown:hover .submenu {
  display: block;
}

.submenu a {
  color: var(--text);
  padding: 12px 18px;
}

.submenu a:hover,
.submenu a:focus {
  background: var(--background);
}

/* =====================================================
   PAGE HEADER
===================================================== */
.page-header {
  background: linear-gradient(135deg, var(--secondary), var(--primary));
  color: var(--white);
  padding: 48px 0;
}

.references-list {
  column-count: 2;
  column-gap: 40px;
}

.reference {
  break-inside: avoid;
}

/* =====================================================
   CONTENT GRID
===================================================== */
.content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 32px;
  margin: 48px auto;
}

.content,
.sidebar {
  background: var(--white);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.sidebar {
  align-self: start;
}

.sidebar h3 {
  margin-top: 0;
}

/* =====================================================
   CONTENT LINKS 
===================================================== */
.content a {
  color: var(--secondary);
  text-decoration: underline;
  font-weight: 500;
}

.content a:hover,
.content a:focus {
  color: var(--primary);
  text-decoration-thickness: 2px;
}

/* =====================================================
   SIDEBAR ICON LIST
===================================================== */
.icon-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.icon-list li + li {
  margin-top: 14px;
}

.icon-list li {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.icon-list a {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 500;
  line-height: 1.4;
  color: var(--secondary);
  text-decoration: none; /* Přepsání globálního podtržení v contentu pro sidebar */
}

.icon-list a:hover,
.icon-list a:focus {
  text-decoration: underline;
}

.icon-list i {
  width: 1.25rem;
  text-align: center;
  flex-shrink: 0;
  color: var(--secondary);
  font-size: 16px;
}

/* =====================================================
   MAP
===================================================== */
#map-ostrava {
  width: 100%;
  height: 320px;
  min-height: 280px;
  border-radius: 8px;
  border: 1px solid #ccc;
  background: #e5e5e5;
  overflow: hidden;
}

/* =====================================================
   FOOTER
===================================================== */
.footer {
  background: var(--primary);
  color: var(--white);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 28px 0;
}

.footer-social {
  width: 40px;
  height: 40px;
  border: 2px solid var(--white);
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 18px;
}

/* =====================================================
   RESPONSIVE
===================================================== */
@media (max-width: 900px) {

  .container {
    padding: 0 16px;
  }

  .header-inner {
    flex-direction: column;
    gap: 16px;
  }

  .content-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .references-list {
    column-count: 1;
  }

  .social-link span {
    display: none;
  }

  #map-ostrava {
    height: 240px;
  }

  /* --- MOBILNÍ MENU --- */
  .menu-toggle {
    display: block; /* Zobrazí ikonu hamburgeru */
    margin-left: auto;
  }

  .nav-links {
    display: none; /* Skryje menu ve výchozím stavu */
    flex-direction: column;
    width: 100%;
    position: absolute;
    top: 100%; /* Rozbalí se hned pod modrým pruhem */
    left: 0;
    background: var(--primary);
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
  }

  .nav-links.active {
    display: flex; /* Zobrazí menu po kliknutí na tlačítko */
  }

  .nav-links a {
    border-top: 1px solid rgba(255, 255, 255, 0.1); /* Jemný oddělovač položek */
  }

  /* Úprava podmenu pro mobily */
  .submenu {
    position: static; /* Zruší "vznášení" a zařadí podmenu přirozeně pod odkaz */
    box-shadow: none;
    background: rgba(0, 0, 0, 0.15); /* Mírně ztmaví pozadí, aby se odlišilo */
    width: 100%;
  }

  .submenu a {
    color: var(--white); /* Text v podmenu bude na mobilu bílý */
    padding-left: 32px; /* Odsazení, aby bylo poznat, že jde o podmenu */
  }

  /* Na mobilu zobrazíme podmenu hned po rozbalení hlavního menu */
  .dropdown .submenu {
    display: block; 
  }
}