.header {
    background-color: var(--imc-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: var(--spacer-md) 0;
}

/* panele przyklejane (np. CalcSlider w .mainSide) muszą zatrzymywać się pod headerem */
.mainSide.sticky-top {
    top: calc(var(--header-height) + var(--spacer-sm));
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacer-xs);
    margin: 0;
    width: 100%;
    max-width: none;
}

.logo-container img {
    max-height: 48px;
    width: auto;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    margin: 0;
    padding: 0;
}

.nav-controls {
    display: flex;
    align-items: center;
    margin: 0;
    padding: 0;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacer-md);
    justify-content: flex-end;
    width: 100%;
    margin: 0;
    padding: 0;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-item a, .nav-item button {
    color: var(--imc-black);
    text-decoration: none;
    font-weight: 600;
    font-size: var(--font-size-sm);
    transition: color 0.3s ease, outline 0.3s ease;
    padding: var(--spacer-xs);
    background: none;
    border: none;
    cursor: pointer;
}

.nav-item a:hover, .nav-item a.current, .nav-item button:hover {
    color: var(--imc-green-dark);
}

.nav-item a:focus, .nav-item button:focus {
    outline: 2px solid var(--imc-green-dark);
    outline-offset: 2px;
    border-radius: 4px;
}

.dropdown {
    position: relative;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--imc-white);
    box-shadow: var(--shadow-md);
    padding: var(--spacer-sm);
    border-radius: var(--imc-radius);
    list-style: none;
    min-width: 200px;
    z-index: 1001;
}

.dropdown:hover .dropdown-menu, .dropdown-toggle[aria-expanded="true"] + .dropdown-menu {
    display: block;
}

.dropdown-menu li a {
    display: block;
    padding: var(--spacer-xs);
    font-size: var(--font-size-xs);
    color: var(--imc-black);
}

.dropdown-menu li a:hover, .dropdown-menu li a:focus {
    color: var(--imc-green-dark);
    outline: 2px solid var(--imc-green-dark);
    outline-offset: 2px;
    border-radius: 4px;
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    padding: var(--spacer-xs);
    margin: 0;
    position: relative;
}

.mobile-toggle:focus {
    outline: 2px solid var(--imc-green-dark);
    outline-offset: 2px;
    border-radius: 4px;
}

.mobile-toggle-icon {
    display: block;
    width: 24px;
    height: 3px;
    background-color: var(--imc-orange);
    position: relative;
    border-radius: 2px;
    box-shadow: 0 0 2px rgba(0, 0, 0, 0.5);
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.mobile-toggle-icon::before,
.mobile-toggle-icon::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 3px;
    background-color: var(--imc-orange);
    left: 0;
    border-radius: 2px;
    box-shadow: 0 0 2px rgba(0, 0, 0, 0.5);
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.mobile-toggle-icon::before {
    top: -8px;
}

.mobile-toggle-icon::after {
    top: 8px;
}

.mobile-toggle[aria-expanded="true"] .mobile-toggle-icon {
    transform: rotate(45deg);
}

.mobile-toggle[aria-expanded="true"] .mobile-toggle-icon::before {
    transform: translateY(8px) rotate(-90deg);
}

.mobile-toggle[aria-expanded="true"] .mobile-toggle-icon::after {
    opacity: 0;
}

.tts-button {
    position: fixed;
    bottom: var(--spacer-md);
    right: var(--spacer-md);
    background-color: var(--imc-white);
    border: 2px solid var(--imc-orange);
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    padding: var(--spacer-sm);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    transition: background-color 0.3s ease, transform 0.3s ease;
}

.tts-button:hover, .tts-button:focus {
    background-color: var(--imc-orange);
    transform: scale(1.1);
}

.tts-button[aria-label="Zatrzymaj odczyt tekstu"] {
    background-color: var(--imc-orange);
}

.tts-button[aria-label="Zatrzymaj odczyt tekstu"] .tts-icon::after {
    content: '■';
    position: absolute;
    top: 0;
    left: 0;
    width: 24px;
    height: 24px;
    line-height: 24px;
    text-align: center;
    color: var(--imc-white);
    font-size: 16px;
}

.tts-icon {
    display: block;
    width: 24px;
    height: 24px;
    line-height: 24px;
    text-align: center;
    color: var(--imc-orange);
    font-size: 20px;
    transition: color 0.3s ease;
}

.tts-button:hover .tts-icon, .tts-button:focus .tts-icon {
    color: var(--imc-white);
}

.tts-disable {
    position: absolute;
    top: -10px;
    right: -10px;
    width: 16px;
    height: 16px;
    background-color: var(--imc-black);
    color: var(--imc-white);
    border-radius: 50%;
    font-size: 12px;
    line-height: 16px;
    text-align: center;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.tts-disable:hover, .tts-disable:focus {
    background-color: var(--imc-green-dark);
}

.tts-button[aria-hidden="true"] {
    display: none;
}