body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #2e2e2e 0%, #1a1a1a 100%);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    color: white; 
    transition: background 0.3s, color 0.3s;
}

body[data-theme="light"] {
    background: linear-gradient(135deg, #f3f4f6 0%, #e5e7eb 100%);
    color: #1f2937; 
}

body[data-theme="light"] .header-bg,
body[data-theme="light"] .main-content-bg,
body[data-theme="light"] footer {
    background: linear-gradient(135deg, #ffffff 0%, #f3f4f6 100%);
}

body[data-theme="light"] .header-bg .text-white,
body[data-theme="light"] .header-bg a.text-white,
body[data-theme="light"] footer .text-white,
body[data-theme="light"] main h1.text-white,
body[data-theme="light"] main p.text-white {
    color: #1f2937;
}

body[data-theme="light"] .text-green-accent {
    color: #16a34a; 
}

body[data-theme="light"] .main-content-bg h2,
body[data-theme="light"] .main-content-bg textarea {
    color: #1f2937;
}

.header-bg {
    background: linear-gradient(135deg, #2e2e2e 0%, #374151 100%);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
}

.main-content-bg {
    background: linear-gradient(135deg, #d1d5db 0%, #e5e7eb 100%);
    transition: transform 0.3s, background 0.3s;
}

.main-content-bg:hover {
    transform: translateY(-4px);
}

.btn-blue {
    background-color: #3b82f6;
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 9999px;
    font-weight: 500;
    transition: transform 0.2s, background-color 0.2s, box-shadow 0.2s;
}

.btn-blue:hover {
    background-color: #2563eb;
    transform: scale(1.05);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

.btn-blue.active {
    background-color: #1d4ed8;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    transform: scale(1);
}

.btn-blue.opacity-70 {
    opacity: 0.7;
}

.text-green-accent {
    color: #4ade80;
}

.text-shadow {
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

textarea {
    resize: none;
    transition: border-color 0.3s, box-shadow 0.3s;
}

textarea:focus {
    box-shadow: 0 0 8px rgba(59, 130, 246, 0.5);
}

#alphabet-modal:not(.hidden) {
    opacity: 1;
    transform: scale(1);
}

#alphabet-modal.hidden {
    opacity: 0;
    transform: scale(0.95);
}

#alphabet-modal > div {
    transform: scale(1);
}

#alphabet-modal.hidden > div {
    transform: scale(0.9);
}

.morse-highlight {
    background-color: rgba(74, 222, 128, 0.4); 
    border-radius: 2px;
    padding: 0 1px;
    transition: background-color 0.1s ease-in-out; 
}

#copy-message {
    position: absolute;
    top: -24px; 
    left: 50%;
    transform: translateX(-50%);
    background-color: #374151; 
    color: white;
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem; 
    border-radius: 0.25rem; 
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
    pointer-events: none; 
    white-space: nowrap;
    z-index: 10; 
}


@media (max-width: 639px) {
    .header-bg {
        flex-direction: column;
        align-items: center;
    }
    .header-bg nav ul {
        margin-top: 1rem;
    }
    .main-content-bg {
        padding: 1rem;
    }
    .main-content-bg > div {
        padding: 0.5rem;
    }
    .btn-blue {
        padding: 0.6rem 1.2rem;
    }

}