:root {
    --primary-color: #4285f4;
    --primary-light: #e8f0fe;
    --primary-dark: #1a73e8;
    --success-color: #34a853;
    --warning-color: #fbbc05;
    --error-color: #ea4335;
    --gray-100: #f8f9fa;
    --gray-200: #e9ecef;
    --gray-300: #dee2e6;
    --gray-400: #ced4da;
    --gray-500: #adb5bd;
    --gray-600: #6c757d;
    --gray-700: #495057;
    --gray-800: #343a40;
    --gray-900: #212529;
    --border-radius: 8px;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

body {
    background-color: #f5f5f7;
    color: var(--gray-800);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Main layout */
.app-container {
    display: flex;
    flex-direction: column;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px;
    gap: 24px;
}

/* Header */
.header {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 16px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.5rem;
}

.logo svg {
    width: 32px;
    height: 32px;
}

/* Input form section */
.input-form {
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    padding: 24px;
}

.section-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 16px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-700);
    margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--gray-300);
    border-radius: var(--border-radius);
    font-size: 0.95rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(66, 133, 244, 0.1);
    outline: none;
}

.form-group textarea {
    min-height: 150px;
    resize: vertical;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--gray-500);
}

.form-help {
    display: block;
    margin-top: 4px;
    font-size: 0.75rem;
    color: var(--gray-600);
}

.tags-container {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 8px;
}

.tag {
    background-color: var(--primary-light);
    color: var(--primary-dark);
    padding: 4px 10px;
    border-radius: 16px;
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    gap: 6px;
}

.tag-remove {
    cursor: pointer;
    background: none;
    border: none;
    color: var(--primary-dark);
    display: flex;
    align-items: center;
    padding: 0;
}

.keyword-input-container {
    display: flex;
    gap: 8px;
}

.keyword-input-container input {
    flex: 1;
}

.keyword-input-container button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    padding: 0 12px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
}

.keyword-input-container button:hover {
    background-color: var(--primary-dark);
}

.actions {
    display: flex;
    justify-content: flex-end;
    gap: 16px;
    margin-top: 24px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

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

.button-primary:hover {
    background-color: var(--primary-dark);
}

.button-primary:disabled {
    background-color: var(--gray-400);
    cursor: not-allowed;
}

.button-secondary {
    background-color: var(--gray-200);
    color: var(--gray-700);
}

.button-secondary:hover {
    background-color: var(--gray-300);
    color: var(--gray-800);
}

.button svg {
    width: 18px;
    height: 18px;
}

/* Results section */
.results-container {
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    max-height: 0;
    overflow: hidden;
    opacity: 0;
}

.results-container.active {
    max-height: 2000px;
    opacity: 1;
    padding: 24px;
    margin-top: 24px;
}

.results-section {
    margin-bottom: 24px;
}

.results-section:last-child {
    margin-bottom: 0;
}

.results-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.results-title svg {
    width: 18px;
    height: 18px;
    color: var(--primary-color);
}

.results-content {
    background-color: var(--gray-100);
    border-radius: var(--border-radius);
    padding: 16px;
    font-size: 0.95rem;
    color: var(--gray-800);
    border-left: 3px solid var(--primary-color);
}

.meta-description {
    margin-top: 8px;
    font-size: 0.9rem;
    line-height: 1.5;
    color: var(--gray-600);
}

.recommendation-item {
    margin-bottom: 12px;
    padding-left: 24px;
    position: relative;
}

.recommendation-item:before {
    content: "";
    position: absolute;
    left: 0;
    top: 8px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--primary-color);
}

/* Spinner */
.spinner-container {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--gray-600);
    font-size: 0.9rem;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--primary-light);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spinner 0.8s linear infinite;
}

@keyframes spinner {
    to { transform: rotate(360deg); }
}

/* Error message */
.error-message {
    color: var(--error-color);
    background-color: #fdeded;
    padding: 12px 16px;
    border-radius: 8px;
    margin: 16px 0;
    border-left: 4px solid var(--error-color);
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    gap: 12px;
}

.error-message svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .app-container {
        padding: 12px;
    }
    
    .actions {
        flex-direction: column;
    }
    
    .button {
        width: 100%;
    }
}

/* Highlight for SEO keywords in content */
.keyword-highlight {
    background-color: rgba(251, 188, 5, 0.2);
    border-bottom: 1px solid var(--warning-color);
}

/* Copy button */
.copy-button {
    background: transparent;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.8rem;
    padding: 4px 8px;
    border-radius: 4px;
    margin-left: auto;
    transition: var(--transition);
}

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

.copy-button svg {
    width: 14px;
    height: 14px;
}

/* Tab navigation for results */
.tabs {
    display: flex;
    border-bottom: 1px solid var(--gray-300);
    margin-bottom: 16px;
}

.tab {
    padding: 8px 16px;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: var(--transition);
    font-size: 0.9rem;
    color: var(--gray-600);
}

.tab.active {
    border-bottom-color: var(--primary-color);
    color: var(--primary-color);
    font-weight: 500;
}

.tab-content {
    display: none;
}

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