.roi-header { margin-bottom: 28px; text-align: center; }
.roi-title { font-size: 32px; font-weight: 800; background: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; margin: 0 0 10px; }
.roi-desc { font-size: 15px; color: #6b7280; margin: 0; }

.roi-inputs { padding: 28px; }

.roi-tabs { display: flex; gap: 10px; margin-bottom: 28px; background: #f9fafb; padding: 6px; border-radius: 14px; }
.roi-tab { flex: 1; padding: 14px 16px; border: none; border-radius: 10px; background: transparent; font-size: 14px; cursor: pointer; transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); position: relative; overflow: hidden; }
.roi-tab:hover { background: rgba(59, 130, 246, 0.05); }
.roi-tab.active { background: white; color: #3b82f6; font-weight: 600; box-shadow: 0 2px 8px rgba(59, 130, 246, 0.15); }

.roi-form { display: flex; flex-direction: column; gap: 16px; }
.roi-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; }

.roi-field { display: flex; flex-direction: column; gap: 6px; }
.roi-field label { font-size: 13px; font-weight: 500; color: #374151; }
.roi-field select { padding: 12px; border: 2px solid #e5e7eb; border-radius: 10px; font-size: 14px; background: white; cursor: pointer; transition: all 0.2s ease; }
.roi-field select:focus { outline: none; border-color: #3b82f6; box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1); }
.roi-field select:hover { border-color: #d1d5db; }

.roi-input-wrap { display: flex; align-items: center; border: 2px solid #e5e7eb; border-radius: 10px; overflow: hidden; transition: all 0.2s ease; background: white; }
.roi-input-wrap:focus-within { border-color: #3b82f6; box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1); }
.roi-prefix { padding: 12px 14px; background: #f9fafb; font-size: 14px; color: #6b7280; border-right: 1px solid #e5e7eb; }
.roi-input-wrap input { flex: 1; padding: 12px; border: none; font-size: 14px; outline: none; }
.roi-suffix-select { border: none; padding: 12px; font-size: 14px; background: #f9fafb; cursor: pointer; outline: none; }

.roi-calc-btn { width: 100%; padding: 16px; background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%); color: white; border: none; border-radius: 12px; font-size: 16px; font-weight: 600; cursor: pointer; margin-top: 24px; box-shadow: 0 4px 14px rgba(59, 130, 246, 0.35); transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); position: relative; overflow: hidden; }
.roi-calc-btn:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(59, 130, 246, 0.45); }
.roi-calc-btn:active { transform: translateY(0); }
.roi-calc-btn::after { content: ''; position: absolute; top: 50%; left: 50%; width: 0; height: 0; background: rgba(255,255,255,0.2); border-radius: 50%; transform: translate(-50%, -50%); transition: width 0.4s, height 0.4s; }
.roi-calc-btn:active::after { width: 200px; height: 200px; }

.roi-results { padding: 24px; display: none; }
.roi-results.show { display: block; }
.roi-results h3 { font-size: 16px; font-weight: 600; margin: 0 0 20px; }

.roi-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 12px; margin-bottom: 24px; }
.roi-result-card { padding: 20px 16px; background: linear-gradient(135deg, #f9fafb 0%, #ffffff 100%); border-radius: 14px; text-align: center; box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04); transition: all 0.3s ease; border: 1px solid #e5e7eb; }
.roi-result-card:hover { transform: translateY(-3px); box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08); }
.roi-result-card .roi-label { display: block; font-size: 12px; color: #6b7280; margin-bottom: 8px; }
.roi-result-card .roi-value { display: block; font-size: 26px; font-weight: 800; background: linear-gradient(135deg, #111827 0%, #374151 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; transition: all 0.3s ease; }
.roi-result-card .roi-value.positive { background: linear-gradient(135deg, #10b981 0%, #059669 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.roi-result-card .roi-value.negative { background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }

.roi-chart-wrap { background: linear-gradient(135deg, #ffffff 0%, #f9fafb 100%); border-radius: 16px; padding: 24px; margin-bottom: 24px; box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04); border: 1px solid #e5e7eb; }
#roiChart { width: 100%; height: auto; }

.roi-analysis { padding: 18px; background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%); border-radius: 12px; font-size: 14px; line-height: 1.7; color: #374151; border: 1px solid #bfdbfe; }
.roi-analysis strong { color: #2563eb; }

.roi-guide { padding: 20px; }
.roi-guide h3 { font-size: 16px; font-weight: 600; margin: 0 0 16px; }
.roi-guide-content { font-size: 14px; line-height: 1.8; color: #374151; }
.roi-guide-content h4 { font-size: 14px; font-weight: 600; margin: 16px 0 8px; }
.roi-guide-content ul { padding-left: 20px; }
.roi-guide-content li { margin: 4px 0; }
.roi-guide-content strong { color: #3b82f6; }

@media (max-width: 640px) {
    .roi-title { font-size: 22px; }
    .roi-row { grid-template-columns: 1fr; }
    .roi-cards { grid-template-columns: repeat(2, 1fr); }
}

@media (prefers-color-scheme: dark) {
    .roi-tab { background: #1f2937; border-color: #374151; }
    .roi-tab.active { background: #1e3a5f; }
    .roi-input-wrap { background: #1f2937; border-color: #374151; }
    .roi-prefix { background: #374151; border-color: #4b5563; color: #9ca3af; }
    .roi-input-wrap input { background: transparent; color: #f9fafb; }
    .roi-field select { background: #1f2937; border-color: #374151; color: #f9fafb; }
    .roi-suffix-select { background: #374151; color: #f9fafb; }
    .roi-result-card { background: #1f2937; }
    .roi-result-card .roi-value { color: #f9fafb; }
    .roi-chart-wrap { background: #1f2937; }
}