/* ==========================================================================
   theme.css - barvy, pisma a zakladni vzhled.
   Design tokens, typography and page basics. Morsky, klidny, detsky citelny.
   (c) 2026 Richard Lipka <lipka@fav.zcu.cz> - MIT license
   ========================================================================== */

:root {
  /* moře / sea */
  --deep-900: #062535;
  --deep-800: #0b3549;
  --deep-700: #124a63;
  --sea-600: #0f6d8c;
  --sea-500: #1f8fa8;
  --sea-400: #3fb0c4;
  --aqua-300: #7fd3e0;
  --aqua-200: #b7e8f1;
  --foam-100: #e4f6fa;
  --foam-50: #f2fbfd;

  /* pevnina a doplňky / land and accents */
  --paper: #ffffff;
  --sand: #f8eed6;
  --sun: #f2a93b;
  --coral: #e8695c;
  --coral-dark: #c2483d;
  --kelp: #2f9e6f;
  --kelp-dark: #1e7551;

  --ink: #0b2a3a;
  --muted: #5c7d8e;
  --line: rgba(11, 42, 58, 0.13);
  --line-soft: rgba(11, 42, 58, 0.07);

  --radius: 20px;
  --radius-sm: 12px;
  --radius-pill: 999px;

  --shadow-sm: 0 2px 6px rgba(6, 37, 53, 0.07);
  --shadow: 0 10px 26px rgba(6, 37, 53, 0.1);
  --shadow-lg: 0 18px 44px rgba(6, 37, 53, 0.16);

  --font: "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  --font-size: 17px;

  --gap: 18px;
  --gap-lg: 26px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: var(--font-size);
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  color: var(--ink);
  line-height: 1.5;
  background:
    radial-gradient(1200px 620px at 15% -12%, #ffffff 0%, rgba(255, 255, 255, 0) 60%),
    linear-gradient(180deg, var(--foam-50) 0%, var(--foam-100) 42%, #d3ecf4 100%);
  background-attachment: fixed;
}

body.is-loading {
  opacity: 0;
}

body {
  transition: opacity 0.25s ease;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  line-height: 1.25;
  color: var(--deep-800);
  font-weight: 700;
}

h1 {
  font-size: 1.45rem;
  letter-spacing: -0.01em;
}
h2 {
  font-size: 1.35rem;
}
h3 {
  font-size: 1.08rem;
}
h4 {
  font-size: 0.95rem;
}

p {
  margin: 0 0 0.6em;
}
p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--sea-600);
}

.muted {
  color: var(--muted);
}

.hint {
  margin: 6px 0 0;
  font-size: 0.82rem;
  line-height: 1.45;
  color: var(--muted);
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

:focus-visible {
  outline: 3px solid var(--sea-400);
  outline-offset: 2px;
  border-radius: 6px;
}

::selection {
  background: var(--aqua-200);
}

/* jemné vlnky u paty stránky / a soft wave at the page foot */
.app-footer {
  position: relative;
  margin-top: var(--gap-lg);
  padding: 34px 26px 30px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--deep-700);
  background: linear-gradient(180deg, rgba(31, 143, 168, 0.09), rgba(15, 109, 140, 0.18));
  border-top: 2px solid rgba(31, 143, 168, 0.22);
}

.app-footer p {
  max-width: 760px;
  margin: 0 auto 6px;
}

.footer-credit {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid rgba(11, 42, 58, 0.12);
  font-size: 0.8rem;
  color: var(--muted);
}

.footer-credit a {
  color: var(--sea-600);
  text-decoration: none;
  font-weight: 600;
}

.footer-credit a:hover {
  text-decoration: underline;
}

/* Logo fakulty je v bile variante, tak dostane tmavy podklad - upravovat
   barvy samotne znacky se nema. / The faculty logo is the white variant, so it
   gets a dark chip; recolouring the mark itself would not be right. */
.footer-affiliation {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-top: 12px;
  font-size: 0.74rem;
  color: var(--muted);
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  padding: 6px 9px;
  border-radius: 8px;
  background: var(--deep-800);
  line-height: 0;
}

.footer-logo img {
  display: block;
  width: auto;
  height: 26px;
}

.footer-logo:hover {
  background: var(--deep-700);
}