:root {
    --bg-primary: #0a0f1a;
    --bg-secondary: #111827;
    --bg-card: #1a2234;
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --border: #1f2937;
    --border-light: #374151;
    --success: #22c55e;
    --danger: #ef4444;
    --warning: #f59e0b;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    padding: 20px;
    min-height: 100vh;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    margin-bottom: 24px;
    transition: color 0.2s;
}

.back-link:hover {
    color: var(--accent);
}

.container {
    max-width: 900px;
    margin: auto;
    background: var(--bg-secondary);
    padding: 32px;
    border: 1px solid var(--border);
    border-radius: 12px;
}

h1 {
    text-align: center;
    color: var(--text-primary);
    font-size: 1.75rem;
    margin-bottom: 24px;
}

#timeUnit-container {
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}

#timeUnit-container label {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

#timeUnit {
    width: auto;
    padding: 8px 12px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    cursor: pointer;
}

#timeUnit:focus {
    outline: none;
    border-color: var(--accent);
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 20px;
}

th, td {
    padding: 12px;
    text-align: center;
    border: 1px solid var(--border);
}

th {
    background-color: var(--bg-card);
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.85rem;
}

td {
    background-color: var(--bg-secondary);
}

input[type="text"], input[type="number"], select {
    width: 100%;
    padding: 10px 12px;
    box-sizing: border-box;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 0.9rem;
    transition: border-color 0.2s;
}

input[type="text"]:focus, input[type="number"]:focus, select:focus {
    outline: none;
    border-color: var(--accent);
}

input[type="text"]::placeholder, input[type="number"]::placeholder {
    color: var(--text-secondary);
}

button {
    color: #fff;
    border: none;
    cursor: pointer;
    border-radius: 6px;
    transition: all 0.2s;
    font-weight: 500;
}

button:hover {
    transform: translateY(-1px);
}

.add-task-button {
    background-color: var(--accent);
    float: right;
    padding: 10px 20px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.add-task-button:hover {
    background-color: var(--accent-hover);
}

.calculate-button {
    background-color: var(--success);
    margin: 40px auto 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 32px;
    font-size: 1rem;
    width: fit-content;
}

.calculate-button:hover {
    background-color: #16a34a;
}

#copy-buttons {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin: 24px 0;
    flex-wrap: wrap;
}

.copy-button {
    background-color: var(--accent);
    padding: 10px 20px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.9rem;
}

.copy-button:hover {
    background-color: var(--accent-hover);
}

.remove-button {
    background-color: var(--danger);
    padding: 8px 16px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
}

.remove-button:hover {
    background-color: #dc2626;
}

#template-buttons {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    margin-bottom: 24px;
}

.save-button,
.load-button {
    background-color: var(--warning);
    padding: 10px 20px;
    color: #fff;
    border: none;
    cursor: pointer;
    border-radius: 6px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-weight: 500;
}

.save-button:hover {
    background-color: #d97706;
}

.load-button {
    background-color: var(--border-light);
}

.load-button:hover {
    background-color: #4b5563;
}

.reset-pert-button {
    background-color: var(--danger);
    color: white;
    border: none;
    padding: 10px 20px;
    font-size: 0.9rem;
    cursor: pointer;
    border-radius: 6px;
}

.reset-pert-button:hover {
    background-color: #dc2626;
}

#result {
    margin-top: 32px;
    padding-top: 32px;
    border-top: 1px solid var(--border);
}

#result p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 16px;
    line-height: 1.7;
}

#result-table {
    margin-top: 20px;
}

#result-table th {
    background-color: var(--accent);
    color: white;
}

#result-table td {
    background-color: var(--bg-card);
}

#result-table tr:last-child td {
    background-color: var(--bg-primary);
    font-weight: 600;
}