* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f5f5f5 0%, #e8e8e8 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 40px 20px;
    color: #323130;
}

h1 {
    font-size: 32px;
    font-weight: 600;
    color: #323130;
    margin-bottom: 40px;
    text-align: center;
    letter-spacing: -0.5px;
}

body>* {
    width: 100%;
    max-width: 700px;
}

label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: #323130;
    margin-bottom: 8px;
    margin-top: 24px;
}

label:first-of-type {
    margin-top: 0;
}

select {
    width: 100%;
    padding: 10px 12px;
    font-size: 14px;
    font-family: 'Segoe UI', sans-serif;
    border: 1px solid #8a8886;
    border-radius: 2px;
    background-color: #ffffff;
    color: #323130;
    cursor: pointer;
    transition: all 0.2s ease;
    outline: none;
}

select:hover {
    border-color: #323130;
}

select:focus {
    border-color: #0078d4;
    box-shadow: 0 0 0 1px #0078d4;
}

textarea {
    width: 100%;
    padding: 12px;
    font-size: 14px;
    font-family: 'Consolas', 'Courier New', monospace;
    border: 1px solid #8a8886;
    border-radius: 2px;
    background-color: #ffffff;
    color: #323130;
    resize: vertical;
    transition: all 0.2s ease;
    outline: none;
    line-height: 1.5;
}

textarea:hover {
    border-color: #323130;
}

textarea:focus {
    border-color: #0078d4;
    box-shadow: 0 0 0 1px #0078d4;
}

textarea::placeholder {
    color: #a19f9d;
}

.row {
    display: flex;
    gap: 12px;
    margin: 24px 0;
}

button {
    flex: 1;
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 600;
    font-family: 'Segoe UI', sans-serif;
    border: none;
    border-radius: 2px;
    cursor: pointer;
    transition: all 0.2s ease;
    outline: none;
    position: relative;
    overflow: hidden;
}

#encodeBtn {
    background-color: #0078d4;
    color: #ffffff;
}

#encodeBtn:hover {
    background-color: #106ebe;
}

#encodeBtn:active {
    background-color: #005a9e;
    transform: scale(0.98);
}

#decodeBtn {
    background-color: #ffffff;
    color: #323130;
    border: 1px solid #8a8886;
}

#decodeBtn:hover {
    background-color: #f3f2f1;
    border-color: #323130;
}

#decodeBtn:active {
    background-color: #edebe9;
    transform: scale(0.98);
}

button:focus-visible {
    box-shadow: 0 0 0 2px #ffffff, 0 0 0 4px #0078d4;
}

/* Fluent acrylic effect on container */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(0, 120, 212, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(106, 27, 154, 0.03) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

/* Subtle elevation shadow */
select,
textarea {
    box-shadow: 0 0.3px 0.9px rgba(0, 0, 0, 0.1),
        0 1.6px 3.6px rgba(0, 0, 0, 0.1);
}

button {
    box-shadow: 0 0.3px 0.9px rgba(0, 0, 0, 0.1),
        0 1.6px 3.6px rgba(0, 0, 0, 0.13);
}

button:hover {
    box-shadow: 0 0.6px 1.8px rgba(0, 0, 0, 0.1),
        0 3.2px 7.2px rgba(0, 0, 0, 0.13);
}

/* Responsive design */
@media (max-width: 600px) {
    body {
        padding: 20px 16px;
    }

    h1 {
        font-size: 24px;
        margin-bottom: 24px;
    }

    .row {
        flex-direction: column;
    }
}