:root {
    --primary: #2563eb;
    --secondary: #1e40af;
    --background: #f8fafc;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', system-ui, sans-serif;
}

body {
    background: linear-gradient(135deg, #f1f5f9, #e2e8f0);
    min-height: 100vh;
    padding: 2rem;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

h1 {
    color: var(--primary);
    margin-bottom: 2rem;
    text-align: center;
}

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

label {
    display: block;
    margin-bottom: 0.5rem;
    color: #1e293b;
    font-weight: 500;
}

input[type="datetime-local"], input[type="time"] {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #cbd5e1;
    border-radius: 0.5rem;
    font-size: 1rem;
}

.timezone-selector {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
}

select {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid #cbd5e1;
    border-radius: 0.5rem;
}

button {
    background: var(--primary);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: background 0.2s;
}

button:hover {
    background: var(--secondary);
}

#results {
    margin-top: 2rem;
    background: #f8fafc;
    padding: 1.5rem;
    border-radius: 0.5rem;
}

.time-card {
    background: white;
    padding: 1rem;
    margin: 0.5rem 0;
    border-radius: 0.5rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.time-option {
    display: flex;
    gap: 1rem;
    align-items: center;
    margin-bottom: 1rem;
}

#time-only-checkbox {
    width: 1.2rem;
    height: 1.2rem;
}

@media (max-width: 600px) {
    body {
        padding: 1rem;
    }
    
    .container {
        padding: 1rem;
    }
    
    .timezone-selector {
        flex-direction: column;
    }
}