/* CSS Variables */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --border-color: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --code-bg: #1e293b;
    --code-text: #e2e8f0;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: all 0.2s ease;
}

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

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

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

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

/* Header */
.header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 1.5rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
}

.title-group h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

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

/* Main Content */
.main-content {
    flex: 1;
    padding: 1.5rem;
    max-width: 1400px;
    margin: 0 auto;
    width: 100%;
}

.generator-layout {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: 1.5rem;
    min-height: calc(100vh - 200px);
}

/* Options Panel */
.options-panel {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.options-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
    padding: 0.75rem;
    background: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    border: none;
    background: transparent;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.813rem;
    color: var(--text-secondary);
    transition: var(--transition);
    white-space: nowrap;
}

.nav-btn:hover {
    background: var(--card-bg);
    color: var(--text-primary);
}

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

.nav-icon {
    font-size: 1rem;
}

/* Option Sections */
.option-section {
    display: none;
    padding: 1.25rem;
    overflow-y: auto;
    flex: 1;
}

.option-section.active {
    display: block;
}

.option-section h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.option-section h3 {
    font-size: 1rem;
    font-weight: 600;
    margin: 1.5rem 0 0.75rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-primary);
}

.section-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 1.25rem;
}

/* Form Elements */
.form-group {
    margin-bottom: 1rem;
}

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

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    cursor: pointer;
    font-size: 0.875rem;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.checkbox-label:hover {
    background: var(--bg-color);
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--primary-color);
    cursor: pointer;
}

input[type="text"],
select {
    width: 100%;
    padding: 0.625rem 0.875rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    background: var(--card-bg);
    color: var(--text-primary);
    transition: var(--transition);
}

input[type="text"]:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

/* Preset Grid */
.preset-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}

.preset-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
    border: 2px solid var(--border-color);
    background: var(--card-bg);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
}

.preset-btn:hover {
    border-color: var(--primary-color);
    background: rgba(37, 99, 235, 0.05);
}

.preset-icon {
    font-size: 1.5rem;
}

.preset-name {
    font-size: 0.813rem;
    font-weight: 500;
    color: var(--text-primary);
    text-align: center;
}

/* Add Rule Form */
.add-rule-form {
    margin-top: 0.75rem;
}

.form-row {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.form-row input,
.form-row select {
    flex: 1;
}

/* Custom List */
.custom-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.custom-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.625rem 0.75rem;
    background: var(--bg-color);
    border-radius: var(--radius-sm);
    font-size: 0.813rem;
}

.custom-item-info {
    display: flex;
    flex-direction: column;
    gap: 0.125rem;
    flex: 1;
    min-width: 0;
}

.custom-item-main {
    font-weight: 500;
    color: var(--text-primary);
    word-break: break-all;
}

.custom-item-sub {
    color: var(--text-secondary);
    font-size: 0.75rem;
    word-break: break-all;
}

.custom-item-remove {
    background: none;
    border: none;
    color: var(--danger-color);
    cursor: pointer;
    padding: 0.25rem;
    font-size: 1.25rem;
    line-height: 1;
    opacity: 0.7;
    transition: var(--transition);
}

.custom-item-remove:hover {
    opacity: 1;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1rem;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

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

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

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

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

.btn-add {
    background: var(--success-color);
    color: white;
    flex-shrink: 0;
}

.btn-add:hover {
    background: #059669;
}

/* Output Panel */
.output-panel {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.output-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    flex-wrap: wrap;
    gap: 0.75rem;
}

.output-header h2 {
    font-size: 1.125rem;
    font-weight: 600;
}

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

.output-container {
    flex: 1;
    overflow: auto;
    background: var(--code-bg);
}

#output-code {
    padding: 1.25rem;
    margin: 0;
    font-family: 'SF Mono', 'Consolas', 'Monaco', monospace;
    font-size: 0.813rem;
    line-height: 1.7;
    color: var(--code-text);
    white-space: pre-wrap;
    word-break: break-word;
    min-height: 300px;
}

.output-info {
    padding: 1rem 1.25rem;
    background: var(--bg-color);
    border-top: 1px solid var(--border-color);
}

.output-info p {
    font-size: 0.813rem;
    color: var(--text-secondary);
    margin-bottom: 0.375rem;
}

.output-info p:last-child {
    margin-bottom: 0;
}

/* Footer */
.footer {
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    padding: 1.25rem;
    margin-top: auto;
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.copyright {
    font-size: 0.813rem;
    color: var(--text-secondary);
}

.powered-by {
    font-size: 0.813rem;
    color: var(--text-secondary);
}

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

.powered-by a: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-md);
    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;
}

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

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

/* Responsive Design */
@media (max-width: 1024px) {
    .generator-layout {
        grid-template-columns: 1fr;
    }

    .options-panel {
        order: 1;
    }

    .output-panel {
        order: 2;
        min-height: 400px;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 0.875rem 1rem;
    }

    .title-group h1 {
        font-size: 1.25rem;
    }

    .main-content {
        padding: 1rem;
    }

    .options-nav {
        padding: 0.5rem;
    }

    .nav-btn {
        padding: 0.5rem;
        font-size: 0.75rem;
    }

    .nav-text {
        display: none;
    }

    .nav-icon {
        font-size: 1.25rem;
    }

    .option-section {
        padding: 1rem;
    }

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

    .output-header {
        flex-direction: column;
        align-items: stretch;
    }

    .output-actions {
        justify-content: stretch;
    }

    .output-actions .btn {
        flex: 1;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .logo {
        width: 40px;
        height: 40px;
    }

    .title-group h1 {
        font-size: 1.125rem;
    }

    .tagline {
        font-size: 0.75rem;
    }

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

    .form-row {
        flex-direction: column;
    }

    #output-code {
        font-size: 0.75rem;
        padding: 1rem;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Selection */
::selection {
    background: var(--primary-color);
    color: white;
}