body {
    margin: 0;
    background: linear-gradient(45deg, #0a192f, #172a45);
    min-height: 100vh;
    font-family: 'Courier New', monospace;
    display: flex;
    justify-content: center;
    align-items: center;
    color: #64ffda;
}

.container {
    position: relative;
    width: 800px;
    padding: 2rem;
}

.background {
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0.1;
    animation: flow 20s linear infinite;
}

@keyframes flow {
    from { transform: translateX(-10%); }
    to { transform: translateX(10%); }
}

.converter-box {
    background: rgba(10, 25, 47, 0.8);
    border: 1px solid #64ffda55;
    border-radius: 10px;
    padding: 2rem;
    backdrop-filter: blur(5px);
    box-shadow: 0 0 30px rgba(100, 255, 218, 0.1);
}

.input-group {
    position: relative;
    margin: 1.5rem 20px 1.5rem 0;
}

textarea {
    width: 100%;
    height: 150px;
    background: #0a192f;
    border: 1px solid #64ffda;
    border-radius: 5px;
    padding: 1rem;
    color: #64ffda;
    font-size: 1.1rem;
    resize: none;
    transition: all 0.3s ease;
}

textarea:focus {
    outline: none;
    box-shadow: 0 0 15px #64ffda33;
}

.label {
    position: absolute;
    top: -10px;
    left: 10px;
    background: #0a192f;
    padding: 0 5px;
    font-size: 0.9rem;
    color: #64ffda;
}

.controls {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
}

.utility-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
}

.convert-btn, .swap-btn, .clear-btn, .copy-btn {
    position: relative;
    background: #1a2f38;
    border: 1px solid #64ffda;
    color: #64ffda;
    padding: 0.8rem 1.5rem;
    border-radius: 5px;
    cursor: pointer;
    overflow: hidden;
    transition: all 0.3s ease;
}

.clear-btn {
    background: #ff525233;
    border-color: #ff5252;
}

.copy-btn {
    background: #64ffda33;
    border-color: #64ffda;
}

.convert-btn:hover, .swap-btn:hover {
    background: #64ffda22;
}

.clear-btn:hover {
    background: #ff525255;
}

.copy-btn:hover {
    background: #64ffda55;
}

.hover-effect {
    position: absolute;
    background: #64ffda33;
    width: 100px;
    height: 100px;
    border-radius: 50%;
    transform: translate(-50%, -50%) scale(0);
    animation: ripple 0.6s ease;
}

@keyframes ripple {
    from { transform: translate(-50%, -50%) scale(0); opacity: 1; }
    to { transform: translate(-50%, -50%) scale(4); opacity: 0; }
}

.error-message {
    color: #ff5252;
    text-align: center;
    margin-top: 1rem;
    height: 20px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.error-message.visible {
    opacity: 1;
}