/* CSS Variables */
:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #e0e7ff;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --error-color: #ef4444;
    --background: #f8fafc;
    --surface: #ffffff;
    --surface-hover: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --radius-sm: 6px;
    --radius: 8px;
    --radius-lg: 12px;
    --transition: all 0.2s ease;
}

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

/* Base Styles */
html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* App Container */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header */
.header {
    text-align: center;
    padding: 2rem 1rem;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.logo-img {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

.header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.tagline {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    padding-bottom: 2rem;
}

/* Expression Section */
.expression-section {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.expression-display label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.expression-input-wrapper {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
}

.expression-input {
    flex: 1;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    font-size: 1.5rem;
    font-weight: 600;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    background: var(--background);
    color: var(--primary-color);
    text-align: center;
    letter-spacing: 0.05em;
}

.expression-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.copy-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.875rem 1.25rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

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

.copy-btn:active {
    transform: scale(0.98);
}

.human-readable {
    font-size: 1rem;
    color: var(--text-secondary);
    text-align: center;
    font-style: italic;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 0.5rem;
    background: var(--surface);
    padding: 0.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.tab-btn {
    flex: 1;
    padding: 0.75rem 1rem;
    background: transparent;
    border: none;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
}

.tab-btn:hover {
    background: var(--surface-hover);
    color: var(--text-primary);
}

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

/* Tab Content */
.tab-content {
    background: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.tab-pane {
    display: none;
    padding: 1.5rem;
}

.tab-pane.active {
    display: block;
}

/* Builder Grid */
.builder-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.field-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.field-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.field-title {
    font-weight: 600;
    color: var(--text-primary);
}

.field-hint {
    font-size: 0.75rem;
    color: var(--text-secondary);
    background: var(--background);
    padding: 0.125rem 0.5rem;
    border-radius: var(--radius-sm);
}

.field-select {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 0.875rem;
    background: var(--surface);
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
}

.field-select:hover {
    border-color: var(--primary-color);
}

.field-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.field-options {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.field-options input[type="number"] {
    padding: 0.625rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 0.875rem;
    width: 100%;
    transition: var(--transition);
}

.field-options input[type="number"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.checkbox-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(50px, 1fr));
    gap: 0.375rem;
}

.checkbox-grid.months {
    grid-template-columns: repeat(auto-fill, minmax(70px, 1fr));
}

.checkbox-grid.weekdays {
    grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
}

.checkbox-item {
    display: flex;
    align-items: center;
    justify-content: center;
}

.checkbox-item input[type="checkbox"] {
    display: none;
}

.checkbox-item label {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 0.5rem;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
}

.checkbox-item label:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.checkbox-item input[type="checkbox"]:checked + label {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.range-inputs {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.range-inputs input {
    flex: 1;
}

.range-inputs span {
    color: var(--text-secondary);
    font-weight: 500;
}

/* Parser Section */
.parser-container {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.parser-input-group label {
    display: block;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.parser-input-wrapper {
    display: flex;
    gap: 0.75rem;
}

.parser-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    font-size: 1rem;
    transition: var(--transition);
}

.parser-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.parse-btn {
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

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

.parse-result {
    background: var(--background);
    border-radius: var(--radius);
    padding: 1.5rem;
    min-height: 150px;
}

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

.parse-breakdown {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.parse-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 0.75rem;
    background: var(--surface);
    border-radius: var(--radius);
    border-left: 3px solid var(--primary-color);
}

.parse-item-label {
    font-weight: 600;
    color: var(--text-primary);
    min-width: 100px;
}

.parse-item-value {
    color: var(--text-secondary);
}

.parse-error {
    color: var(--error-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Presets Grid */
.presets-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 0.75rem;
}

.preset-btn {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.375rem;
    padding: 1rem;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.preset-btn:hover {
    border-color: var(--primary-color);
    background: var(--primary-light);
}

.preset-name {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.875rem;
}

.preset-cron {
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    font-size: 0.8125rem;
    color: var(--primary-color);
    background: var(--surface);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
}

/* Next Runs Section */
.next-runs-section {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.next-runs-section h2 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.next-runs-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.next-runs-list li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background: var(--background);
    border-radius: var(--radius);
    font-size: 0.875rem;
}

.next-runs-list li::before {
    content: '';
    width: 8px;
    height: 8px;
    background: var(--success-color);
    border-radius: 50%;
    flex-shrink: 0;
}

.next-runs-list .run-date {
    font-weight: 500;
    color: var(--text-primary);
}

.next-runs-list .run-relative {
    color: var(--text-secondary);
    font-size: 0.8125rem;
}

/* Footer */
.footer {
    padding: 1.5rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
    margin-top: auto;
}

.footer p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text-primary);
    color: white;
    padding: 0.875rem 1.5rem;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header {
        padding: 1.5rem 0.5rem;
    }

    .header h1 {
        font-size: 1.5rem;
    }

    .tagline {
        font-size: 0.875rem;
    }

    .expression-input {
        font-size: 1.25rem;
        padding: 0.75rem;
    }

    .expression-input-wrapper {
        flex-direction: column;
    }

    .copy-btn {
        justify-content: center;
    }

    .tabs {
        flex-wrap: wrap;
    }

    .tab-btn {
        flex: 1 1 auto;
        min-width: calc(50% - 0.25rem);
    }

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

    .parser-input-wrapper {
        flex-direction: column;
    }

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

    .parse-item {
        flex-direction: column;
        gap: 0.25rem;
    }

    .parse-item-label {
        min-width: unset;
    }
}

@media (max-width: 480px) {
    .app-container {
        padding: 0 0.75rem;
    }

    .expression-section,
    .tab-content,
    .next-runs-section {
        padding: 1rem;
    }

    .checkbox-grid {
        grid-template-columns: repeat(5, 1fr);
    }

    .checkbox-grid.weekdays {
        grid-template-columns: repeat(4, 1fr);
    }

    .checkbox-grid.months {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* Print Styles */
@media print {
    .tabs,
    .copy-btn,
    .parse-btn,
    .preset-btn {
        display: none;
    }

    .tab-pane {
        display: block !important;
    }

    .expression-section,
    .tab-content,
    .next-runs-section {
        box-shadow: none;
        border: 1px solid var(--border-color);
    }
}