:root {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-card: #f1f5f9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --accent: #10b981;
    --accent-hover: #059669;
    --border: #e2e8f0;
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border: #475569;
}

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

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

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    padding: 40px 0;
    position: relative;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--accent), #f97316);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.tagline { color: var(--text-secondary); }

.dark-mode-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    padding: 10px 15px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.2rem;
}

.tool-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 30px;
    margin-bottom: 30px;
}

.controls {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.control-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-secondary);
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
}

.checkbox-group input {
    width: 18px;
    height: 18px;
    accent-color: var(--accent);
}

select, input[type="number"] {
    width: 100%;
    padding: 12px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 14px;
}

select:focus, input:focus {
    outline: none;
    border-color: var(--accent);
}

.generate-btn {
    width: 100%;
    padding: 16px;
    background: var(--accent);
    border: none;
    border-radius: 8px;
    color: white;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

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

.output-section {
    margin-top: 20px;
}

.output-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.output-header span {
    color: var(--text-secondary);
    font-size: 14px;
}

textarea {
    width: 100%;
    padding: 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 14px;
    resize: vertical;
    line-height: 1.8;
}

.copy-btn {
    padding: 8px 16px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.copy-btn:hover {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

.trust-badges {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
    margin: 40px 0;
}

.badge {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 30px;
    font-size: 14px;
}

.faq-section {
    margin-top: 40px;
}

.faq-section h2 {
    text-align: center;
    margin-bottom: 30px;
}

.faq-item {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 10px;
    margin-bottom: 10px;
}

.faq-item summary {
    padding: 16px 20px;
    cursor: pointer;
    font-weight: 500;
    list-style: none;
}

.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: '+'; float: right; }
.faq-item[open] summary::after { content: '−'; }

.faq-item p {
    padding: 0 20px 16px;
    color: var(--text-secondary);
}

/* Use Cases Section */
.use-cases-section {
    margin-top: 50px;
}

.use-cases-section h2 {
    text-align: center;
    margin-bottom: 15px;
    font-size: 1.8rem;
}

.section-intro {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.use-case-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.use-case {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    border-left: 4px solid var(--accent);
}

.use-case h3 {
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.use-case p {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.6;
}

footer {
    text-align: center;
    padding: 30px;
    color: var(--text-secondary);
    border-top: 1px solid var(--border);
    margin-top: 40px;
}

@media (max-width: 768px) {
    h1 { font-size: 1.8rem; }
    .controls { grid-template-columns: 1fr; }
}

/* Theme Toggle Button */
.theme-toggle {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: none;
    background: var(--bg-secondary, #fff);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    cursor: pointer;
    font-size: 1.25rem;
    transition: transform 0.2s;
    z-index: 1000;
}

.theme-toggle:hover {
    transform: scale(1.1);
}

[data-theme="dark"] .theme-toggle {
    background: #1e293b;
}