:root {
    --bg: #f8f9fa;
    --card: #ffffff;
    --accent: #007bff;
    --accent-hover: #0056b3;
    --muted: #6c757d;
    --soft-border: #e2e8f0;
    --text-color: #2d3748;
    --header-color: #1a202c;
    --bg-result: #ebf8ff;
    --text-result: #2b6cb0;
    --border-result: #bee3f8;
}

* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    background: var(--bg);
    color: var(--text-color);
    line-height: 1.5;
}

.container {
    max-width: 650px;
    margin: 4rem auto;
    padding: 0 1.5rem;
}

h1 {
    margin-top: 0;
    margin-bottom: 2rem;
    color: var(--header-color);
    text-align: center;
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.05em;
}

.card {
    background: var(--card);
    border: 1px solid var(--soft-border);
    padding: 2.5rem;
    border-radius: 12px;
    margin-bottom: 2rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.02);
}

.card h2 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    color: var(--header-color);
    font-size: 1.5rem;
    font-weight: 700;
}

.small {
    color: var(--muted);
    font-size: 0.875rem;
    margin-bottom: 1.5rem;
    margin-top: 0;
}

.input-group {
    margin-bottom: 1.25rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: #4a5568;
}

input[type=time], input[type=number] {
    padding: 0.75rem 1rem;
    border: 1.5px solid var(--soft-border);
    border-radius: 8px;
    width: 100%;
    font-size: 1rem;
    color: var(--text-color);
    background-color: #fff;
    transition: all 0.2s ease-in-out;
}

input[type=time]:focus, input[type=number]:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.15);
    outline: none;
}

.duration-row {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.duration-col {
    flex: 1;
}

.actions {
    margin-top: 2rem;
    display: flex;
    gap: 1rem;
}

button {
    flex: 1;
    background: var(--accent);
    color: white;
    padding: 0.875rem 1.5rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.2s ease;
    display: inline-flex;
    justify-content: center;
    align-items: center;
}

button:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

button:active {
    transform: translateY(0);
}

button.secondary {
    background: #edf2f7;
    color: #4a5568;
}

button.secondary:hover {
    background-color: #e2e8f0;
    color: #2d3748;
}

.result {
    margin-top: 1.75rem;
    font-weight: 700;
    font-size: 1.1rem;
    text-align: center;
    color: var(--text-result);
    padding: 1rem;
    border-radius: 8px;
    background-color: var(--bg-result);
    border: 1px solid var(--border-result);
    display: none; /* Wird per JS angezeigt */
}

@media(max-width: 480px) {
    .duration-row {
        flex-direction: column;
        gap: 0.75rem;
    }
    .actions {
        flex-direction: column;
    }
}