/* 블랙스콜스 마스터 클래스 – PSAR과 디자인 통일, 페이지 전용 보조 스타일 */

/* Step 1 데이터 행 (explanation-box 안에서 사용) */
.black-data-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
    margin-top: 1rem;
}
@media (max-width: 900px) {
    .black-data-row { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
    .black-data-row { grid-template-columns: 1fr; }
}
.black-data-item {
    background: white;
    border: 1px solid #bae6fd;
    border-radius: 8px;
    padding: 1rem 1.25rem;
    text-align: center;
}
.black-data-item-vol {
    position: relative;
}
.black-data-vol-hint {
    display: block;
    font-size: 0.7rem;
    color: #64748b;
    margin-top: 4px;
}
.black-data-vol-hint.high { color: #b91c1c; }
.black-data-vol-hint.low { color: #047857; }
.black-data-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: #0369a1;
    margin-bottom: 4px;
}
.black-data-value {
    font-size: 1.35rem;
    font-weight: 700;
    color: #1e3a8a;
}

/* 차트 캡션 (chart-container 내) */
.chart-caption {
    margin-bottom: 10px;
    color: #64748b;
    font-size: 0.95rem;
}
.chart-caption strong { color: #1e3a8a; }

/* ========== Step 2: 현대식 레이아웃 (고정 변수 + 조절 슬라이더) ========== */
.black-step2-section {
    margin-bottom: 1.75rem;
}
.black-step2-section-title {
    font-size: 0.9rem;
    font-weight: 600;
    color: #475569;
    margin: 0 0 1rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.black-step2-section-title i {
    color: #64748b;
}

.black-step2-desc {
    font-size: 0.875rem;
    color: #64748b;
    line-height: 1.5;
    margin: 0 0 1rem 0;
    padding: 0;
}

/* ========== Step 2 시각: 계산 흐름 + 페이오프 ========== */
.black-s2-flow-wrap,
.black-s2-payoff-wrap {
    margin: 1.5rem 0;
}
.black-s2-flow-caption {
    font-size: 0.8rem;
    font-weight: 600;
    color: #64748b;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin: 0 0 0.75rem 0;
}
.black-s2-flow {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 0.5rem 0.25rem;
    padding: 1.25rem;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border: 1px solid #bae6fd;
    border-radius: 12px;
}
.black-s2-flow-node {
    background: #fff;
    border-radius: 10px;
    padding: 0.6rem 1rem;
    text-align: center;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
    border: 1px solid #e2e8f0;
}
.black-s2-flow-node.black-s2-flow-inputs {
    padding: 0.5rem 0.75rem;
}
.black-s2-flow-label {
    display: block;
    font-size: 0.7rem;
    font-weight: 600;
    color: #64748b;
    margin-bottom: 4px;
}
.black-s2-flow-formula {
    font-size: 0.75rem;
    color: #475569;
    font-family: ui-monospace, monospace;
}
.black-s2-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
    justify-content: center;
}
.black-s2-pill {
    display: inline-block;
    padding: 0.2rem 0.5rem;
    font-size: 0.8rem;
    font-weight: 600;
    color: #0369a1;
    background: #e0f2fe;
    border-radius: 6px;
}
.black-s2-arrow {
    color: #94a3b8;
    font-size: 0.9rem;
}
.black-s2-flow-outputs .black-s2-output-pair {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    margin-top: 2px;
}
.black-s2-out {
    font-weight: 800;
    font-size: 1.1rem;
    padding: 0.25rem 0.6rem;
    border-radius: 8px;
}
.black-s2-out.call {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    color: #047857;
    border: 1px solid #6ee7b7;
}
.black-s2-out.put {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    color: #b91c1c;
    border: 1px solid #fca5a5;
}
@media (max-width: 768px) {
    .black-s2-flow { flex-wrap: wrap; justify-content: flex-start; }
    .black-s2-arrow { flex: 0 0 auto; }
}

/* Step 2 페이오프 미니 다이어그램 */
.black-s2-payoff-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}
@media (max-width: 540px) {
    .black-s2-payoff-row { grid-template-columns: 1fr; }
}
.black-s2-payoff-card {
    background: #fff;
    border-radius: 12px;
    padding: 1rem;
    text-align: center;
    border: 1px solid #e2e8f0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}
.black-s2-payoff-card.call {
    border-left: 4px solid #22c55e;
    background: linear-gradient(135deg, #fafafa 0%, #f0fdf4 100%);
}
.black-s2-payoff-card.put {
    border-left: 4px solid #ef4444;
    background: linear-gradient(135deg, #fafafa 0%, #fef2f2 100%);
}
.black-s2-payoff-title {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: #374151;
    margin-bottom: 0.5rem;
}
.black-s2-payoff-svg {
    width: 100%;
    max-width: 140px;
    height: auto;
    margin: 0 auto 0.5rem;
    display: block;
}
.black-s2-payoff-card.call .black-s2-payoff-svg { color: #047857; }
.black-s2-payoff-card.put .black-s2-payoff-svg { color: #b91c1c; }
.black-s2-payoff-hint {
    font-size: 0.75rem;
    color: #64748b;
}

/* Step 2 카드 스타일 (왜 / 공식) */
#black-step-2 .explanation-box.black-s2-card {
    border-radius: 12px;
    border-left: 4px solid #0ea5e9;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}
#black-step-2 .explanation-box.black-s2-card.why {
    border-left-color: #8b5cf6;
}
#black-step-2 .explanation-box.black-s2-card.formula {
    border-left-color: #0ea5e9;
}

/* Step 2 설명: 공식 박스 */
.black-step2-formula-box {
    margin-top: 1rem;
}
.black-formula-block {
    margin-top: 0.75rem;
    padding: 1rem 1.25rem;
    background: #f8fafc;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
}
.black-formula-line {
    font-family: ui-monospace, "SF Mono", monospace;
    font-size: 0.9rem;
    color: #1e293b;
    margin: 0.35rem 0;
    line-height: 1.6;
}

/* 고정 변수 카드 (기업 데이터) */
.black-step2-fixed {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 1.25rem 1.5rem;
}
.black-fixed-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}
@media (max-width: 640px) {
    .black-fixed-grid { grid-template-columns: 1fr; }
}
.black-fixed-card {
    background: #fff;
    border-radius: 10px;
    padding: 1rem 1.25rem;
    text-align: center;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
    border: 1px solid #e2e8f0;
}
.black-fixed-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: #64748b;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    margin-bottom: 4px;
}
.black-fixed-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: #0f172a;
}

/* 조절 변수 (슬라이더) */
.black-step2-sliders {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 1.25rem 1.5rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
.black-sliders-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-top: 0.5rem;
}
@media (max-width: 768px) {
    .black-sliders-grid { grid-template-columns: 1fr; }
}
.black-slider-item {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.black-slider-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: #334155;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.black-slider-value {
    font-weight: 700;
    color: #1e40af;
    font-size: 1rem;
}
.black-slider {
    width: 100%;
    height: 10px;
    border-radius: 5px;
    background: #e2e8f0;
    outline: none;
    -webkit-appearance: none;
    appearance: none;
}
.black-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 6px rgba(59, 130, 246, 0.4);
    transition: transform 0.15s;
}
.black-slider::-webkit-slider-thumb:hover {
    transform: scale(1.08);
}
.black-slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 6px rgba(59, 130, 246, 0.4);
}

/* Step 3 Sensitivity Bar */
.black-s3-sensitivity-wrap {
    margin: 1.25rem 0;
    padding: 1rem 1.25rem;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border: 1px solid #e2e8f0;
    border-radius: 12px;
}
.black-s3-sensitivity-bars {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}
.black-s3-sens-item {
    display: grid;
    grid-template-columns: 24px 1fr 48px;
    align-items: center;
    gap: 0.5rem;
}
.black-s3-sens-label {
    font-weight: 700;
    color: #475569;
    font-size: 0.9rem;
}
.black-s3-sens-track {
    height: 10px;
    background: #e2e8f0;
    border-radius: 5px;
    overflow: hidden;
}
.black-s3-sens-fill {
    height: 100%;
    background: linear-gradient(90deg, #3b82f6 0%, #2563eb 100%);
    border-radius: 5px;
    transition: width 0.3s ease;
}
.black-s3-sens-fill.theta {
    background: linear-gradient(90deg, #f59e0b 0%, #d97706 100%);
}
.black-s3-sens-value {
    font-size: 0.8rem;
    font-weight: 600;
    color: #64748b;
    font-family: ui-monospace, monospace;
}
.black-s3-theta-hint {
    margin: 0.75rem 0 0 0;
    font-size: 0.8rem;
    color: #92400e;
    display: flex;
    align-items: center;
    gap: 0.35rem;
}
.black-s3-theta-hint i {
    color: #f59e0b;
}

/* 이론가 카드 */
.black-step2-prices {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 1.25rem 1.5rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
.black-price-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 0.5rem;
}
.black-price-item {
    position: relative;
    border-radius: 10px;
    padding: 1.25rem 1.5rem;
    text-align: center;
    transition: transform 0.2s;
}
.black-price-item:hover {
    transform: translateY(-2px);
}
.black-price-tooltip {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-top: 8px;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    font-size: 0.75rem;
    line-height: 1.5;
    text-align: left;
    box-shadow: 0 4px 14px rgba(0,0,0,0.12);
    z-index: 10;
    pointer-events: none;
}
.black-price-item:hover .black-price-tooltip {
    display: block;
}
.black-price-item.call .black-price-tooltip {
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
    color: #14532d;
}
.black-price-item.put .black-price-tooltip {
    background: #fff1f2;
    border: 1px solid #fecaca;
    color: #7f1d1d;
}
.black-price-tooltip .black-tt-title {
    display: block;
    font-weight: 700;
    margin-bottom: 6px;
    font-size: 0.8rem;
}
.black-price-tooltip .black-tt-line {
    display: block;
    margin-bottom: 2px;
    font-family: ui-monospace, monospace;
}
.black-price-tooltip .black-tt-formula {
    display: block;
    margin: 6px 0 4px 0;
    font-weight: 600;
    font-size: 0.78rem;
}
.black-price-item.call {
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
    border: 1px solid #a7f3d0;
    box-shadow: 0 2px 8px rgba(34, 197, 94, 0.12);
}
.black-price-item.put {
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
    border: 1px solid #fecaca;
    box-shadow: 0 2px 8px rgba(239, 68, 68, 0.12);
}
.black-price-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: #475569;
    margin-bottom: 6px;
}
.black-price-item.call .black-price-value { color: #047857; font-weight: 800; font-size: 1.5rem; letter-spacing: -0.02em; }
.black-price-item.put .black-price-value { color: #b91c1c; font-weight: 800; font-size: 1.5rem; letter-spacing: -0.02em; }

/* Step 2 차트 */
.black-step2-chart-wrap {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 1.25rem 1.5rem;
    margin-bottom: 1rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
.black-step2-chart-wrap .chart-caption {
    margin-bottom: 12px;
    font-weight: 600;
    color: #475569;
}
.black-step2-chart {
    width: 100%;
    height: 220px;
    min-height: 200px;
}

/* ========== Step 3: N(d₁), N(d₂) ========== */
.black-step3-section {
    margin-bottom: 1.75rem;
}
.black-step3-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-top: 0.75rem;
}
@media (max-width: 640px) {
    .black-step3-grid { grid-template-columns: 1fr; }
}
.black-step3-card {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    padding: 1rem 1.25rem;
    text-align: center;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
.black-step3-card.highlight {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border-color: #94a3b8;
    font-weight: 600;
}
.black-step3-label {
    display: block;
    font-size: 0.8rem;
    color: #64748b;
    margin-bottom: 4px;
}
.black-step3-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: #1e293b;
    font-family: ui-monospace, monospace;
}
.black-step3-card.highlight .black-step3-value {
    color: #0369a1;
}

/* ========== Step 4: 현대적·교육적 재구성 ========== */
.black-s4-flow-wrap {
    margin: 1.5rem 0;
}
.black-s4-flow {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 1.25rem;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border: 1px solid #e2e8f0;
    border-radius: 12px;
}
.black-s4-flow-chip {
    padding: 0.35rem 0.75rem;
    font-size: 0.85rem;
    font-weight: 600;
    color: #475569;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    box-shadow: 0 1px 2px rgba(0,0,0,0.04);
}
.black-s4-flow-chip.highlight {
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    border-color: #93c5fd;
    color: #1d4ed8;
}
.black-s4-flow-chip.call {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    border-color: #6ee7b7;
    color: #047857;
}
.black-s4-flow-chip.put {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    border-color: #fca5a5;
    color: #b91c1c;
}
.black-s4-arrow {
    color: #94a3b8;
    font-size: 0.85rem;
}

/* Step 4 핵심 수치 카드 */
.black-s4-values-wrap {
    margin: 1.75rem 0;
}
.black-s4-section-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: #475569;
    margin: 0 0 0.75rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.black-s4-section-title i {
    color: #64748b;
}
.black-s4-values-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
}
@media (max-width: 900px) {
    .black-s4-values-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 480px) {
    .black-s4-values-grid { grid-template-columns: 1fr; }
}
.black-s4-value-card {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 1.25rem 1rem;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    transition: transform 0.2s, box-shadow 0.2s;
}
.black-s4-value-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}
.black-s4-value-card.highlight {
    border-color: #93c5fd;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
}
.black-s4-value-card.highlight.nd .black-s4-value-num {
    color: #1d4ed8;
}
.black-s4-value-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: #64748b;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    margin-bottom: 6px;
}
.black-s4-value-num {
    display: block;
    font-size: 1.5rem;
    font-weight: 800;
    color: #0f172a;
    font-family: ui-monospace, monospace;
    letter-spacing: -0.02em;
}
.black-s4-value-hint {
    display: block;
    font-size: 0.7rem;
    color: #94a3b8;
    margin-top: 4px;
}

/* Step 4 CDF 시각화 */
.black-s4-cdf-wrap {
    margin: 1.75rem 0;
    padding: 1.25rem 1.5rem;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}
.black-s4-cdf-desc {
    font-size: 0.875rem;
    color: #64748b;
    line-height: 1.5;
    margin: 0 0 1rem 0;
}
.black-s4-cdf-visual {
    text-align: center;
}
.black-s4-cdf-svg {
    width: 100%;
    max-width: 320px;
    height: auto;
    margin: 0 auto;
    display: block;
    color: #3b82f6;
}
.black-s4-cdf-curve {
    filter: drop-shadow(0 2px 4px rgba(59,130,246,0.2));
}
.black-s4-cdf-formula {
    font-size: 0.8rem;
    color: #475569;
    font-family: ui-monospace, monospace;
    margin: 0.75rem 0 0 0;
}

/* Step 4 델타 카드 */
.black-s4-delta-wrap {
    margin: 1.75rem 0;
}
.black-s4-delta-desc {
    font-size: 0.875rem;
    color: #64748b;
    line-height: 1.5;
    margin: 0 0 1rem 0;
}
.black-s4-delta-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}
@media (max-width: 640px) {
    .black-s4-delta-row { grid-template-columns: 1fr; }
}
.black-s4-delta-card {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    border: 1px solid #e2e8f0;
}
.black-s4-delta-card.call {
    border-top: 4px solid #22c55e;
    background: linear-gradient(180deg, #f0fdf4 0%, #fff 30%);
}
.black-s4-delta-card.put {
    border-top: 4px solid #ef4444;
    background: linear-gradient(180deg, #fef2f2 0%, #fff 30%);
}
.black-s4-delta-header {
    padding: 0.9rem 1.25rem;
    font-weight: 700;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.black-s4-delta-card.call .black-s4-delta-header { color: #047857; background: rgba(34,197,94,0.08); }
.black-s4-delta-card.put .black-s4-delta-header { color: #b91c1c; background: rgba(239,68,68,0.08); }
.black-s4-delta-body {
    padding: 1rem 1.25rem 1.25rem;
}
.black-s4-delta-formula {
    display: block;
    font-family: ui-monospace, monospace;
    font-size: 1.1rem;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 0.75rem;
}
.black-s4-delta-arrow-wrap {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: #475569;
    margin-bottom: 0.5rem;
}
.black-s4-delta-arrow-wrap i {
    color: #94a3b8;
}
.black-s4-delta-card.call .black-s4-delta-arrow-wrap span:last-child { color: #047857; font-weight: 600; }
.black-s4-delta-card.put .black-s4-delta-arrow-wrap span:last-child { color: #b91c1c; font-weight: 600; }
.black-s4-delta-hint {
    font-size: 0.75rem;
    color: #64748b;
    margin: 0;
    line-height: 1.4;
}

/* Step 4 공식에서의 역할 */
.black-s4-role-wrap {
    margin: 1.75rem 0;
    padding: 1.25rem 1.5rem;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border: 1px solid #e2e8f0;
    border-radius: 12px;
}
.black-s4-role-formulas {
    margin-top: 0.5rem;
}
.black-s4-role-line {
    font-family: ui-monospace, monospace;
    font-size: 0.9rem;
    color: #334155;
    margin: 0.4rem 0;
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 0.5rem;
}
.black-s4-role-formula {
    word-break: break-all;
}
.black-s4-mark {
    padding: 0.15rem 0.35rem;
    border-radius: 4px;
    font-weight: 700;
}
.black-s4-mark.nd1 {
    background: rgba(59, 130, 246, 0.2);
    color: #1d4ed8;
}
.black-s4-mark.nd2 {
    background: rgba(139, 92, 246, 0.2);
    color: #5b21b6;
}
.black-s4-role-note {
    font-size: 0.8rem;
    color: #64748b;
    margin: 0.75rem 0 0 0;
    line-height: 1.5;
}
.black-s4-role-note .black-s4-mark {
    padding: 0.1rem 0.25rem;
    font-size: 0.85em;
}

/* ========== Step 5: 델타 헤징 ========== */
.black-s5-flow-wrap {
    margin: 1.5rem 0;
}
.black-s5-flow {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}
.black-s5-flow-card {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.25rem;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}
.black-s5-flow-label {
    font-weight: 600;
    color: #475569;
    font-size: 0.9rem;
}
.black-s5-flow-arrow {
    color: #94a3b8;
    font-size: 0.85rem;
}
.black-s5-flow-delta {
    font-family: ui-monospace, monospace;
    font-weight: 700;
    color: #1e293b;
    font-size: 0.95rem;
}
.black-s5-flow-hedge {
    padding: 0.35rem 0.75rem;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 600;
}
.black-s5-flow-card:first-child .black-s5-flow-hedge {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    color: #047857;
    border: 1px solid #6ee7b7;
}
.black-s5-flow-card:last-child .black-s5-flow-hedge {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    color: #b91c1c;
    border: 1px solid #fca5a5;
}

.black-s5-values-wrap {
    margin: 1.75rem 0;
}
.black-s5-delta-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}
@media (max-width: 640px) {
    .black-s5-delta-row { grid-template-columns: 1fr; }
}
.black-s5-delta-box {
    border-radius: 12px;
    padding: 1.25rem 1.5rem;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    border: 1px solid #e2e8f0;
}
.black-s5-delta-box.call {
    border-top: 4px solid #22c55e;
    background: linear-gradient(180deg, #f0fdf4 0%, #fff 25%);
}
.black-s5-delta-box.put {
    border-top: 4px solid #ef4444;
    background: linear-gradient(180deg, #fef2f2 0%, #fff 25%);
}
.black-s5-delta-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: #64748b;
    margin-bottom: 6px;
}
.black-s5-delta-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 800;
    font-family: ui-monospace, monospace;
    color: #0f172a;
}
.black-s5-delta-box.call .black-s5-delta-value { color: #047857; }
.black-s5-delta-box.put .black-s5-delta-value { color: #b91c1c; }
.black-s5-delta-hint {
    display: block;
    font-size: 0.8rem;
    color: #64748b;
    margin-top: 8px;
}
#black-step-5 .explanation-box.black-s5-neutral-wrap {
    border-left: 4px solid #0ea5e9;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

/* Step 5 델타 중립 시뮬레이터 (단순·직관) */
.black-s5-simulator-wrap {
    margin: 1.75rem 0;
    padding: 1.25rem 1.5rem;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.06);
}
.black-s5-sim-lead {
    font-size: 1rem;
    color: #475569;
    line-height: 1.5;
    margin: 0 0 1.25rem 0;
}
.black-s5-one-btn-wrap {
    text-align: center;
    margin-bottom: 1.25rem;
}
.black-s5-main-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 1rem 1.75rem;
    font-size: 1.1rem;
    font-weight: 700;
    color: #fff;
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    border: none;
    border-radius: 12px;
    cursor: pointer;
    box-shadow: 0 4px 14px rgba(14, 165, 233, 0.4);
    transition: transform 0.2s, box-shadow 0.2s;
}
.black-s5-main-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(14, 165, 233, 0.45);
}
.black-s5-main-btn:active {
    transform: translateY(0);
}
.black-s5-main-btn.black-s5-btn-done {
    background: linear-gradient(135deg, #22c55e 0%, #16a34a 100%);
    box-shadow: 0 4px 14px rgba(34, 197, 94, 0.4);
}
.black-s5-one-line {
    margin: 0.75rem 0 0 0;
    font-size: 1rem;
    color: #475569;
}
.black-s5-one-line strong {
    color: #0ea5e9;
    font-size: 1.1rem;
}
.black-s5-table-hint {
    font-size: 0.9rem;
    color: #64748b;
    margin: 0 0 0.75rem 0;
}
.black-s5-table-hint strong { color: #ca8a04; }
.black-s5-advanced {
    margin-top: 1.25rem;
    padding-top: 1rem;
    border-top: 1px solid #e2e8f0;
    font-size: 0.9rem;
}
.black-s5-advanced summary {
    cursor: pointer;
    color: #64748b;
}
.black-s5-simulator-inputs {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 1rem;
    margin-top: 0.75rem;
    margin-bottom: 0;
}
.black-s5-sim-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    font-weight: 600;
    color: #475569;
}
.black-s5-sim-input {
    width: 120px;
    padding: 0.5rem 0.75rem;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    font-size: 0.95rem;
}
.black-s5-sim-btn {
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    color: #fff;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
}
.black-s5-sim-btn:hover {
    opacity: 0.95;
}
.black-s5-table-wrap {
    overflow-x: auto;
    margin-bottom: 1rem;
}
.black-s5-sim-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}
.black-s5-sim-table th,
.black-s5-sim-table td {
    padding: 0.65rem 1rem;
    border: 1px solid #e2e8f0;
    text-align: right;
}
.black-s5-sim-table th {
    background: #f8fafc;
    font-weight: 600;
    color: #475569;
}
.black-s5-sim-table .black-s5-td-label {
    text-align: left;
    font-weight: 600;
    color: #475569;
}
.black-s5-sim-table .black-s5-total-row td {
    background: #fef9c3;
    font-weight: 700;
    color: #0f172a;
}
.black-s5-sim-table .black-s5-total-row .black-s5-td-label {
    background: #fef9c3;
}
.black-s5-sim-warning {
    display: none;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: #fef2f2;
    border: 1px solid #fecaca;
    border-radius: 8px;
    color: #b91c1c;
    font-size: 0.875rem;
    font-weight: 500;
}
.black-s5-sim-warning[aria-hidden="false"] {
    display: flex;
}
.black-s5-sim-warning i {
    flex-shrink: 0;
}

/* ========== 공통: Step 6–9 리드·카드·요약 ========== */
.black-step-lead {
    margin: 1rem 0 1.5rem;
    padding: 1.25rem 1.5rem;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border: 1px solid #bae6fd;
    border-radius: 12px;
    border-left: 4px solid #0284c7;
}
.black-step-lead-p {
    margin: 0;
    font-size: 1rem;
    line-height: 1.7;
    color: #0c4a6e;
}
.black-step-lead strong { color: #0369a1; }
.black-step-lead em { font-style: italic; color: #075985; }

.black-concept-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin: 1.5rem 0;
}
.black-concept-cards--two {
    grid-template-columns: repeat(2, 1fr);
}
@media (max-width: 900px) {
    .black-concept-cards { grid-template-columns: 1fr; }
    .black-concept-cards--two { grid-template-columns: 1fr; }
}
.black-concept-card {
    padding: 1.25rem;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    transition: box-shadow 0.2s, border-color 0.2s;
}
.black-concept-card:hover {
    border-color: #cbd5e1;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}
.black-concept-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.25rem;
    height: 2.25rem;
    margin-bottom: 0.75rem;
    background: #f1f5f9;
    color: #475569;
    font-weight: 700;
    font-size: 1rem;
    border-radius: 8px;
}
.black-concept-icon--green { background: #dcfce7; color: #166534; }
.black-concept-icon--amber { background: #fef3c7; color: #b45309; }
.black-concept-icon--blue { background: #dbeafe; color: #1d4ed8; }
.black-concept-card h4 {
    margin: 0 0 0.5rem;
    font-size: 0.95rem;
    font-weight: 600;
    color: #1e293b;
}
.black-concept-card p {
    margin: 0;
    font-size: 0.875rem;
    line-height: 1.55;
    color: #475569;
}
.black-concept-value {
    margin-top: 0.75rem !important;
    font-size: 1.1rem !important;
    font-weight: 700;
    color: #0369a1;
}

.black-key-takeaway {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin: 1.5rem 0 1rem;
    padding: 1rem 1.25rem;
    background: linear-gradient(135deg, #fefce8 0%, #fef9c3 100%);
    border: 1px solid #fde047;
    border-radius: 10px;
}
.black-key-takeaway i {
    flex-shrink: 0;
    margin-top: 0.15rem;
    color: #ca8a04;
    font-size: 1.1rem;
}
.black-key-takeaway p {
    margin: 0;
    font-size: 0.9rem;
    line-height: 1.6;
    color: #713f12;
}

/* ========== Step 6: 감마 (Gamma) ========== */
.black-s6-interactive-block {
    margin: 1.5rem 0;
    padding: 1.25rem;
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
}
.black-s6-gauge-wrap {
    margin: 1rem 0 1.25rem;
}
.black-s6-gauge-label {
    font-size: 0.95rem;
    font-weight: 600;
    color: #334155;
    margin: 0 0 0.35rem;
}
.black-s6-gauge-bar {
    position: relative;
    height: 1.5rem;
    background: #e2e8f0;
    border-radius: 999px;
    overflow: visible;
}
.black-s6-gauge-fill {
    height: 100%;
    background: linear-gradient(90deg, #22c55e, #f59e0b);
    border-radius: 999px;
    transition: width 0.3s ease;
    min-width: 4%;
    max-width: 96%;
}
.black-s6-gauge-center {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    font-size: 0.7rem;
    font-weight: 600;
    color: #64748b;
    pointer-events: none;
    z-index: 1;
}
.black-s6-gauge-value {
    font-size: 0.95rem;
    color: #475569;
    margin-top: 0.5rem;
    font-weight: 500;
}
.black-s6-slider-wrap {
    margin: 1rem 0;
}
.black-slider-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    font-weight: 500;
    color: #334155;
    margin-bottom: 0.5rem;
}
.black-slider-value {
    color: #0369a1;
    font-weight: 700;
    font-size: 1.05rem;
}
.black-slider {
    width: 100%;
    max-width: 360px;
    accent-color: #0369a1;
    cursor: pointer;
}
.black-s6-curve-wrap {
    margin: 1.5rem 0;
}
.black-s6-curve-hint {
    margin-top: 0.75rem;
}
.black-s6-plot {
    min-height: 280px;
    width: 100%;
    border-radius: 8px;
}

/* ========== Step 7: 변동성 미산정 ========== */
.black-s7-interactive-block {
    margin: 1.5rem 0;
    padding: 1.25rem;
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
}
.black-s7-slider-wrap {
    margin: 0 0 1.25rem;
}
.black-s7-bells-wrap {
    margin: 1rem 0;
}
.black-s7-plot {
    min-height: 280px;
    width: 100%;
    border-radius: 8px;
}
.black-s7-verdict-wrap {
    margin-top: 1.25rem;
    padding-top: 1.25rem;
    border-top: 1px dashed #cbd5e1;
    text-align: center;
}
.black-s7-verdict-label {
    font-size: 0.9rem;
    font-weight: 500;
    color: #475569;
    margin: 0 0 0.5rem;
}
.black-s7-badge {
    display: inline-block;
    padding: 0.6rem 1.25rem;
    border-radius: 10px;
    font-weight: 700;
    font-size: 1.1rem;
    transition: transform 0.2s, box-shadow 0.2s;
}
.black-s7-badge:hover {
    transform: scale(1.02);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
.black-s7-badge.black-s7-cheap {
    background: linear-gradient(135deg, #dcfce7, #bbf7d0);
    color: #166534;
    border: 2px solid #22c55e;
}
.black-s7-badge.black-s7-expensive {
    background: linear-gradient(135deg, #fef2f2, #fecaca);
    color: #b91c1c;
    border: 2px solid #ef4444;
}
.black-s7-verdict-hint {
    margin: 0.5rem 0 0;
    font-size: 0.8rem;
    color: #64748b;
    line-height: 1.5;
}

/* ========== Step 8: 변동성 차익 ========== */
.black-s8-scenario {
    margin: 1.25rem 0;
    padding: 1rem 1.25rem;
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
    border-radius: 10px;
}
.black-s8-scenario h4 {
    margin: 0 0 0.75rem;
    font-size: 0.95rem;
    color: #166534;
}
.black-s8-scenario-list {
    margin: 0;
    padding-left: 1.25rem;
    font-size: 0.9rem;
    line-height: 1.7;
    color: #15803d;
}
.black-s8-table-block {
    margin: 1.5rem 0;
}
.black-s8-table-wrap {
    margin: 0.75rem 0;
    overflow-x: auto;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.06);
}
.black-s8-table {
    width: 100%;
    min-width: 320px;
}
.black-s8-total-row td {
    background: #fef9c3 !important;
    font-weight: 700;
    color: #713f12;
}
.black-s8-magic {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    font-weight: 700;
    color: #0369a1;
    background: #e0f2fe;
    border-radius: 8px;
    border: 1px solid #7dd3fc;
}
.black-s8-magic i {
    color: #0284c7;
}

/* ========== Step 9: 교차 옵션 헤징 ========== */
.black-s9-interactive-block {
    margin: 1.5rem 0;
    padding: 1.25rem;
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
}
.black-s9-plot {
    min-height: 300px;
    width: 100%;
    border-radius: 8px;
}
.black-s9-cost-block {
    margin: 1.5rem 0;
}
.black-s9-cost-block h4 {
    margin: 0 0 1rem;
    font-size: 1rem;
    color: #334155;
}
.black-s9-cost-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}
@media (max-width: 640px) {
    .black-s9-cost-cards { grid-template-columns: 1fr; }
}
.black-s9-cost-card {
    padding: 1.25rem;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.black-s9-cost-card--highlight {
    border-color: #3b82f6;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.15);
}
.black-s9-cost-label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: #475569;
    margin-bottom: 0.5rem;
}
.black-s9-cost-num {
    display: block;
    font-size: 1.35rem;
    font-weight: 700;
    color: #0369a1;
    margin-bottom: 0.5rem;
}
.black-s9-cost-note {
    margin: 0;
    font-size: 0.8rem;
    line-height: 1.5;
    color: #64748b;
}

/* ========== Step 10: 완료 / 요약 ========== */
.black-s6-summary {
    margin: 1.5rem 0;
    padding: 1.25rem 1.5rem;
    background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
    border: 1px solid #bbf7d0;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}
.black-s6-list {
    margin: 0 0 1rem 0;
    padding-left: 1.5rem;
    color: #166534;
    line-height: 1.8;
    font-size: 0.95rem;
}
.black-s6-cta {
    margin: 0;
    font-size: 0.9rem;
    color: #15803d;
}
.black-s6-restart {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1rem;
    padding: 0.75rem 1.25rem;
    background: #fff;
    border: 1px solid #22c55e;
    color: #16a34a;
    border-radius: 10px;
    font-weight: 600;
    text-decoration: none;
    transition: background 0.2s, color 0.2s;
}
.black-s6-restart:hover {
    background: #22c55e;
    color: #fff;
}