/* CSS Reset and Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #6b7280;
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --background-color: #f3f4f6;
    --card-background: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --critical-color: #ef4444;
    --critical-bg: #fef2f2;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header Styles */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #7c3aed 100%);
    color: white;
    padding: 2rem 1rem;
    text-align: center;
}

.logo-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.logo {
    height: 48px;
    width: auto;
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.025em;
}

.tagline {
    font-size: 1.1rem;
    opacity: 0.9;
    margin-top: 0.5rem;
}

/* Main Content */
main {
    flex: 1;
    padding: 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

/* Card Styles */
.card {
    background: var(--card-background);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.card h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--border-color);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1rem;
}

.section-header h2 {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.section-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

/* Form Styles */
.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.375rem;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.625rem 0.875rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
    background: var(--card-background);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: #9ca3af;
}

.form-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-top: 1rem;
}

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.625rem 1.25rem;
    font-size: 0.9375rem;
    font-weight: 500;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.8125rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-hover);
}

.btn-secondary {
    background: var(--background-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background: var(--danger-hover);
}

/* Task List Styles */
.task-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.task-item {
    display: flex;
    flex-direction: column;
    padding: 1rem;
    background: var(--background-color);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--primary-color);
    transition: transform 0.2s, box-shadow 0.2s;
}

.task-item:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.task-item.critical {
    border-left-color: var(--critical-color);
    background: var(--critical-bg);
}

.task-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.task-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.task-title strong {
    font-size: 1rem;
    color: var(--text-primary);
}

.task-id {
    font-size: 0.75rem;
    background: var(--primary-color);
    color: white;
    padding: 0.125rem 0.5rem;
    border-radius: 9999px;
}

.task-actions {
    display: flex;
    gap: 0.375rem;
}

.task-actions button {
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
    background: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
}

.task-actions button:hover {
    background: var(--border-color);
}

.task-actions button.delete:hover {
    background: var(--danger-color);
    color: white;
    border-color: var(--danger-color);
}

.task-details {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.task-detail {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.task-detail-label {
    font-weight: 500;
}

.task-dependencies {
    margin-top: 0.5rem;
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

.task-dependencies span {
    display: inline-block;
    background: var(--card-background);
    padding: 0.125rem 0.375rem;
    border-radius: var(--radius-sm);
    margin-right: 0.25rem;
    border: 1px solid var(--border-color);
}

.task-description {
    margin-top: 0.5rem;
    font-size: 0.8125rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* Dependency Map */
.dependency-map {
    min-height: 200px;
    background: var(--background-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    overflow-x: auto;
}

.dependency-graph {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.dependency-level {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
}

.dependency-node {
    background: var(--card-background);
    border: 2px solid var(--primary-color);
    border-radius: var(--radius-md);
    padding: 0.75rem 1rem;
    min-width: 120px;
    text-align: center;
    position: relative;
}

.dependency-node.critical {
    border-color: var(--critical-color);
    background: var(--critical-bg);
}

.dependency-node .node-id {
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--primary-color);
}

.dependency-node.critical .node-id {
    color: var(--critical-color);
}

.dependency-node .node-name {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 150px;
}

.dependency-node .node-time {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

.level-label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
    text-align: center;
}

.dependency-arrow {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.5rem;
}

/* Analysis Results */
.analysis-results {
    background: var(--background-color);
    border-radius: var(--radius-md);
    padding: 1rem;
}

.analysis-warning {
    background: #fef3c7;
    border: 1px solid #f59e0b;
    border-radius: var(--radius-md);
    padding: 1rem;
    margin-bottom: 1rem;
    color: #92400e;
}

.analysis-warning strong {
    display: block;
    margin-bottom: 0.25rem;
}

/* Summary Section */
.summary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.summary-card {
    background: var(--background-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    text-align: center;
}

.summary-card.highlight {
    background: var(--primary-color);
    color: white;
}

.summary-label {
    display: block;
    font-size: 0.8125rem;
    font-weight: 500;
    margin-bottom: 0.375rem;
    opacity: 0.8;
}

.summary-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
}

.critical-path-display {
    background: var(--critical-bg);
    border: 1px solid var(--critical-color);
    border-radius: var(--radius-md);
    padding: 1rem;
}

.critical-path-display h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--critical-color);
    margin-bottom: 0.75rem;
}

#criticalPathTasks {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem;
}

.critical-task-badge {
    background: var(--critical-color);
    color: white;
    padding: 0.375rem 0.75rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
}

.critical-arrow {
    color: var(--critical-color);
    font-weight: bold;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--card-background);
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1.125rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0.25rem;
    line-height: 1;
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-content form {
    padding: 1.5rem;
}

/* Footer Styles */
footer {
    background: var(--text-primary);
    color: white;
    text-align: center;
    padding: 1.5rem 1rem;
    margin-top: auto;
}

footer p {
    font-size: 0.875rem;
}

footer a {
    color: #93c5fd;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

footer a:hover {
    color: #bfdbfe;
    text-decoration: underline;
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    bottom: 1rem;
    right: 1rem;
    z-index: 1001;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toast {
    background: var(--text-primary);
    color: white;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    animation: slideIn 0.3s ease;
    max-width: 300px;
}

.toast.success {
    background: var(--success-color);
}

.toast.error {
    background: var(--danger-color);
}

.toast.warning {
    background: var(--warning-color);
    color: var(--text-primary);
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    header {
        padding: 1.5rem 1rem;
    }

    header h1 {
        font-size: 1.5rem;
    }

    .logo {
        height: 36px;
    }

    .tagline {
        font-size: 1rem;
    }

    main {
        padding: 1rem;
    }

    .card {
        padding: 1rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .section-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .task-header {
        flex-direction: column;
    }

    .task-actions {
        align-self: flex-end;
    }

    .summary-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .summary-value {
        font-size: 1.25rem;
    }
}

@media (max-width: 480px) {
    .logo-container {
        flex-direction: column;
        gap: 0.5rem;
    }

    header h1 {
        font-size: 1.25rem;
    }

    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }

    .section-actions {
        width: 100%;
        justify-content: flex-end;
    }

    .summary-grid {
        grid-template-columns: 1fr;
    }

    .modal-content {
        margin: 0.5rem;
    }
}

/* Print Styles */
@media print {
    header {
        background: none;
        color: var(--text-primary);
    }

    .btn, .task-actions, .section-actions, .form-actions {
        display: none;
    }

    .card {
        box-shadow: none;
        border: 1px solid var(--border-color);
        break-inside: avoid;
    }

    footer {
        background: none;
        color: var(--text-primary);
    }

    footer a {
        color: var(--primary-color);
    }
}