:root {
    --primary-color: #00f7ff;
    --secondary-color: #7b2cbf;
    --background-dark: #0a192f;
    --background-darker: #071426;
    --text-color: #e6f1ff;
    --text-muted: #8892b0;
    --success-color: #64ffda;
    --error-color: #ff6b6b;
}

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

body {
    font-family: 'Roboto', sans-serif;
    background-color: var(--background-dark);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    flex: 1;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    padding: 1rem;
    border-bottom: 1px solid rgba(0, 247, 255, 0.2);
}

h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 10px rgba(0, 247, 255, 0.3);
}

.tagline {
    color: var(--text-muted);
    font-size: 1.1rem;
}

main {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

.control-panel {
    background: rgba(10, 25, 47, 0.8);
    padding: 2rem;
    border-radius: 10px;
    border: 1px solid rgba(0, 247, 255, 0.1);
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
}

.input-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
    font-weight: 300;
}

input[type="number"],
select {
    width: 100%;
    padding: 0.8rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(0, 247, 255, 0.3);
    border-radius: 5px;
    color: var(--text-color);
    font-size: 1rem;
    transition: all 0.3s ease;
}

input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(0, 247, 255, 0.2);
}

button {
    background: linear-gradient(45deg, var(--secondary-color), var(--primary-color));
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-right: 1rem;
    margin-bottom: 1rem;
    font-family: 'Orbitron', sans-serif;
    text-transform: uppercase;
    letter-spacing: 1px;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 247, 255, 0.3);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.glow-button {
    position: relative;
    overflow: hidden;
}

.glow-button::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(
        45deg,
        transparent,
        rgba(255, 255, 255, 0.2),
        transparent
    );
    transform: rotate(45deg);
    transition: 0.6s;
}

.glow-button:hover::after {
    left: 100%;
}

.output-panel {
    background: rgba(10, 25, 47, 0.8);
    padding: 2rem;
    border-radius: 10px;
    border: 1px solid rgba(0, 247, 255, 0.1);
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
    min-height: 200px;
}

.otp-display {
    font-family: 'Courier New', monospace;
    white-space: pre-wrap;
    word-break: break-all;
    line-height: 1.8;
    background: rgba(0, 0, 0, 0.2);
    padding: 1.5rem;
    border-radius: 5px;
    border: 1px solid rgba(0, 247, 255, 0.1);
}

.placeholder {
    color: var(--text-muted);
    text-align: center;
    font-style: italic;
}

footer {
    text-align: center;
    margin-top: 3rem;
    padding: 1.5rem;
    color: var(--text-muted);
    font-size: 0.9rem;
    border-top: 1px solid rgba(0, 247, 255, 0.1);
}

/* Animation */
@keyframes pulse {
    0% { opacity: 0.6; }
    50% { opacity: 1; }
    100% { opacity: 0.6; }
}

/* Responsive Design */
@media (min-width: 768px) {
    main {
        grid-template-columns: 300px 1fr;
    }
    
    .control-panel {
        position: sticky;
        top: 2rem;
        height: fit-content;
    }
}

@media print {
    body * {
        visibility: hidden;
    }
    
    .otp-display,
    .otp-display * {
        visibility: visible;
    }
    
    .otp-display {
        position: absolute;
        left: 0;
        top: 0;
        width: 100%;
        height: 100%;
        background: white;
        color: black;
        padding: 2cm;
        font-size: 12pt;
        line-height: 1.5;
        white-space: pre;
        overflow: visible;
    }
}