:root {
    --navbar-bg: #f5c400;
    --navbar-hover: #d9a800;

    --text-color: #1a1a1a;

    --main-margin: clamp(12px, 4vw, 80px);

    --navbar-height: 70px;

    --transition-speed: 0.25s;
}

html, body {
  height: 100%;
  margin: 0;
}

body {
    background-color: var(--body-bg);
    color: var(--text-color);

    font-family: Arial, Helvetica, sans-serif;

    display: flex;
    flex-direction: column;
    min-height: 100vh;

}

.main {
    flex: 1;

    display: flex;
    flex-direction: column;
    align-items: flex-start;

    min-height: 100vh;
    margin-left: 3%;
    margin-right: 3%;
}

.main #main-content {
    margin-left: var(--main-margin);
    margin-right: var(--main-margin);

    color: var(--content-text);

    padding-top: 25px;
    padding-bottom: 25px;
}

h1 {
    text-align: center;

    margin-top: 10px;

    font-size: clamp(2rem, 4vw, 3rem);
}

.navbar {
    background-color: var(--navbar-bg);

    border-bottom: 2px solid rgba(0, 0, 0, 0.15);

    position: sticky;
    top: 0;

    z-index: 1000;
}

.navbar ul {
    list-style: none;

    margin: 0;
    padding: 0 var(--main-margin);

    display: flex;

    justify-content: space-between;
    align-items: center;

    min-height: var(--navbar-height);
}

.navbar .nav-brand {
    font-size: 1.3rem;
    font-weight: bold;
}

.navbar .nav-links {
    display: flex;

    gap: 8px;
}

.navbar li {
    display: flex;
    align-items: center;
}

.navbar a {
    color: var(--text-color);

    text-decoration: none;

    padding: 12px 16px;

    border-radius: 8px;

    font-weight: 600;

    transition:
        background-color var(--transition-speed) ease,
        transform var(--transition-speed) ease,
        opacity var(--transition-speed) ease;
}

.navbar a:hover {
    background-color: var(--navbar-hover);

    transform: translateY(-1px);
}

footer {
    padding: 40px 20px;

    margin-top: auto;

    border-top: 3px solid;

    transition:
        background 0.3s ease,
        color 0.3s ease;

    background: var(--footer-bg);

    color: var(--footer-color);

    border-top-color: var(--footer-border-color);
}

.footer-content {
    max-width: 1200px;

    margin: 0 auto;

    display: flex;

    justify-content: space-between;

    gap: 40px;

    flex-wrap: wrap;
}

.footer-brand h2 {
    font-size: 1.8rem;

    margin-bottom: 10px;

    color: var(--footer-brand-color-h2);
}

.footer-brand p {
    line-height: 1.5;

    max-width: 300px;

    color: var(--footer-brand-color-p);
}

.footer-contact p {
    margin-bottom: 8px;

    font-weight: bold;

    color: var(--footer-contact-color);
}

.callnumlink {
    text-decoration: none;

    font-size: 1.1rem;

    transition: opacity 0.2s ease;

    color: var(--footer-numberlink);
}

.callnumlink:hover {
    opacity: 0.7;
}

#header {
  position: sticky;
  top: 0;
  z-index: 1000;
}

#theme-toggle {
  position: fixed;
  bottom: 20px;
  right: 20px;

  width: 44px;
  height: 44px;

  z-index: 9999;

  cursor: pointer;

  background: var(--navbar-bg);
  border-radius: 50%;
  padding: 6px;

  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.25);

  transition: transform 0.15s ease, opacity 0.15s ease;
}

#theme-toggle:hover {
  transform: scale(1.08);
}

#theme-toggle:active {
  transform: scale(0.92);
}

.theme-toggle:hover {
  transform: scale(1.1);
  opacity: 0.85;
}