* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; line-height: 1.6; color: #333; background: #f9fafb; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

.navbar { background: white; border-bottom: 1px solid #e5e7eb; display: flex; justify-content: space-between; align-items: center; padding: 1rem 20px; position: sticky; top: 0; }
.logo { font-size: 1.3rem; font-weight: bold; color: #2563eb; }
.logo a { text-decoration: none; color: inherit; }

.btn-primary, .btn-secondary, .btn-large, .btn-small { padding: 0.75rem 1.5rem; border: none; border-radius: 0.5rem; cursor: pointer; font-weight: 600; text-decoration: none; display: inline-block; }
.btn-primary { background: #2563eb; color: white; }
.btn-primary:hover { background: #1d4ed8; }
.btn-secondary { background: #e5e7eb; color: #333; }
.btn-secondary:hover { background: #d1d5db; }
.btn-large { padding: 1rem 2rem; font-size: 1.1rem; }
.btn-small { padding: 0.5rem 1rem; font-size: 0.9rem; }

.hero { background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%); color: white; padding: 4rem 20px; text-align: center; }
.hero h1 { font-size: 2.5rem; margin-bottom: 1rem; }
.hero p { font-size: 1.1rem; opacity: 0.95; margin-bottom: 2rem; }
.hero .btn-large { background: white; color: #2563eb; }

.features { padding: 4rem 20px; background: white; }
.features h2, .pricing h2, .how h2 { text-align: center; font-size: 2rem; margin-bottom: 3rem; color: #1f2937; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 2rem; }
.card { background: #f9fafb; padding: 2rem; border-radius: 0.75rem; text-align: center; border: 1px solid #e5e7eb; }
.card .icon { font-size: 2rem; display: block; margin-bottom: 1rem; }
.card h3 { margin-bottom: 0.5rem; color: #1f2937; }
.card p { color: #6b7280; font-size: 0.9rem; }

.pricing { padding: 4rem 20px; }
.pricing-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 2rem; }
.pricing-card { background: white; border: 2px solid #e5e7eb; border-radius: 0.75rem; padding: 2rem; text-align: center; }
.pricing-card.featured { border-color: #2563eb; box-shadow: 0 10px 30px rgba(37, 99, 235, 0.1); transform: scale(1.05); }
.pricing-card h3 { font-size: 1.3rem; margin-bottom: 1rem; }
.price { font-size: 1.8rem; font-weight: bold; color: #2563eb; margin-bottom: 1rem; }
.pricing-card ul { list-style: none; text-align: left; margin-bottom: 1rem; }
.pricing-card li { padding: 0.5rem 0; color: #6b7280; }

.how { padding: 4rem 20px; background: white; }
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.step { text-align: center; }
.step .num { display: inline-block; width: 2.5rem; height: 2.5rem; background: #2563eb; color: white; border-radius: 50%; font-weight: bold; line-height: 2.5rem; margin-bottom: 0.5rem; }

footer { background: #1f2937; color: white; padding: 2rem 20px; text-align: center; }

.app-container { padding: 2rem 20px; min-height: 80vh; }
.container-app { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; }

.form-section { background: white; padding: 2rem; border-radius: 0.75rem; border: 1px solid #e5e7eb; }
.form-section h2 { margin-bottom: 1.5rem; color: #1f2937; }
.form-group { margin-bottom: 1.5rem; }
.form-group label { display: block; margin-bottom: 0.5rem; font-weight: 600; color: #1f2937; }
.form-group input, .form-group select { width: 100%; padding: 0.75rem; border: 1px solid #d1d5db; border-radius: 0.5rem; font-size: 1rem; }
.form-group input:focus, .form-group select:focus { outline: none; border-color: #2563eb; box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1); }

.preview-section { background: white; padding: 2rem; border-radius: 0.75rem; border: 1px solid #e5e7eb; }
.preview-section h2 { margin-bottom: 1.5rem; color: #1f2937; }
.email-container { background: #f3f4f6; border: 1px solid #d1d5db; border-radius: 0.5rem; overflow: hidden; margin-bottom: 1.5rem; }
.email-header { background: #e5e7eb; padding: 1rem; font-size: 0.85rem; color: #6b7280; }
.email-body { padding: 1.5rem; }
.email-body p { margin-bottom: 1rem; }
.signature-preview { background: white; padding: 1rem; border: 1px solid #e5e7eb; border-radius: 0.5rem; font-size: 0.9rem; }

.actions { display: flex; gap: 1rem; flex-wrap: wrap; margin-bottom: 1.5rem; }
.actions button { flex: 1; min-width: 150px; }

#historyBox { background: #f9fafb; padding: 1rem; border-radius: 0.5rem; border: 1px solid #e5e7eb; }
#historyBox h3 { margin-bottom: 1rem; font-size: 0.95rem; }
#historyList { max-height: 200px; overflow-y: auto; }
.history-item { padding: 0.5rem; background: white; border-radius: 0.25rem; margin-bottom: 0.5rem; cursor: pointer; font-size: 0.85rem; }
.history-item:hover { background: #e5e7eb; }

@media (max-width: 768px) {
    .container-app { grid-template-columns: 1fr; }
    .hero h1 { font-size: 1.8rem; }
    .steps { grid-template-columns: 1fr 1fr; }
    .actions { flex-direction: column; }
    .actions button { width: 100%; }
}