/*-------------------------------------------------------------------------------------
                                        ROOT / BASE
--------------------------------------------------------------------------------------*/
:root {
    --primary-blue: #0052cc;
    --primary-blue-dark: #003ea1;
    --hero-gradient: linear-gradient(135deg, #0061ff 0%, #0033aa 100%);
    --bg-light: #f8fafc;
    --bg-soft: #f1f5f9;
    --white: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --text-light: rgba(255, 255, 255, 0.86);
    --border-color: #e2e8f0;
    --success: #0f766e;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 18px 35px rgba(15, 23, 42, 0.12);
    --radius: 12px;
    --radius-lg: 18px;
    --transition: all 0.3s ease;
    --container-width: 1200px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: 'Inter', sans-serif;
    color: var(--text-main);
    background: var(--white);
    line-height: 1.65;
}

img {
    max-width: 100%;
    display: block;
}

a {
    color: var(--primary-blue);
    text-decoration: none;
}

a:hover {
    text-decoration: none;
}

.container {
    width: min(var(--container-width), calc(100% - 32px));
    margin: 0 auto;
}

.section-padding {
    padding: 72px 0;
}

.bg-light {
    background: var(--bg-light);
}

.bg-white {
    background: var(--white);
}

/*-------------------------------------------------------------------------------------
                                      TYPOGRAPHY HELPERS
--------------------------------------------------------------------------------------*/
.section-header {
    margin-bottom: 32px;
}

.section-header.text-left {
    text-align: left;
}

.section-label {
    display: inline-block;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--primary-blue);
    margin-bottom: 10px;
}

.section-header h2 {
    margin: 0 0 12px;
    font-size: clamp(1.8rem, 2.2vw, 2.5rem);
    line-height: 1.2;
    color: var(--text-main);
}

.section-header p {
    margin: 0;
    max-width: 760px;
    color: var(--text-muted);
    font-size: 1rem;
}

.content-flow p {
    margin: 0 0 18px;
    color: var(--text-main);
}

.content-flow p:last-child {
    margin-bottom: 0;
}

/*-------------------------------------------------------------------------------------
                                           BUTTONS
--------------------------------------------------------------------------------------*/
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 13px 22px;
    border-radius: 999px;
    font-weight: 700;
    font-size: 0.95rem;
    transition: var(--transition);
    border: 1px solid transparent;
    text-align: center;
}

.btn-primary,
.btn-solid {
    background: var(--white);
    color: var(--primary-blue);
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover,
.btn-solid:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary,
.btn-outline {
    background: transparent;
    color: var(--white);
    border-color: rgba(255, 255, 255, 0.34);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.08);
}

.btn-outline {
    color: var(--primary-blue);
    border-color: var(--border-color);
    background: var(--white);
}

.btn-outline:hover {
    border-color: var(--primary-blue);
    transform: translateY(-2px);
}

/*-------------------------------------------------------------------------------------
                                             HERO
--------------------------------------------------------------------------------------*/
.strategy-hero {
    background: var(--hero-gradient);
    color: var(--white);
    padding: 44px 0 64px;
    overflow: hidden;
}

.hero-container {
    position: relative;
}

.breadcrumb {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
    margin-bottom: 28px;
    font-size: 0.9rem;
}

.breadcrumb a {
    color: rgba(255, 255, 255, 0.82);
}

.breadcrumb span {
    color: rgba(255, 255, 255, 0.75);
}

.hero-content {
    display: grid;
    gap: 28px;
    align-items: start;
}

.hero-text h1 {
    margin: 0 0 16px;
    font-size: clamp(2.1rem, 4vw, 3.4rem);
    line-height: 1.08;
    color: var(--white);
}

.hero-intro,
.hero-support {
    color: var(--text-light);
    max-width: 760px;
}

.hero-intro {
    margin: 0 0 16px;
    font-size: 1.07rem;
}

.hero-support {
    margin: 0;
    font-size: 1rem;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 28px;
}

/*-------------------------------------------------------------------------------------
                                       PAGE SHELL / SIDEBAR
--------------------------------------------------------------------------------------*/
.page-shell {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 28px;
    align-items: start;
}

.main-content {
    min-width: 0;
}

.side-panel {
    display: grid;
    gap: 20px;
    position: sticky;
    top: 100px;
}

.side-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 22px;
    box-shadow: var(--shadow-sm);
}

.side-card-icon {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: #e8f0ff;
    color: var(--primary-blue);
    margin-bottom: 14px;
}

.side-card h3 {
    margin: 0 0 10px;
    font-size: 1.1rem;
}

.side-card p {
    margin: 0 0 14px;
    color: var(--text-muted);
    font-size: 0.95rem;
}

.side-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.side-links li + li {
    margin-top: 10px;
}

.side-links a {
    color: var(--primary-blue);
    font-weight: 600;
}

.tip-list {
    display: grid;
    gap: 12px;
}

.tip-row {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    padding: 10px 0;
    border-bottom: 1px solid var(--border-color);
}

.tip-row:last-child {
    border-bottom: 0;
    padding-bottom: 0;
}

.tip-row span {
    color: var(--text-muted);
    font-size: 0.92rem;
}

.tip-row strong {
    color: var(--text-main);
    font-size: 0.92rem;
    text-align: right;
}

/*-------------------------------------------------------------------------------------
                                         CARD GRIDS
--------------------------------------------------------------------------------------*/
.calculator-grid,
.steps-grid,
.benefits-grid,
.mistakes-grid,
.related-grid {
    display: grid;
    gap: 20px;
}

.calculator-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.related-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.steps-grid,
.benefits-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

/*-------------------------------------------------------------------------------------
                           TYPES OF INVESTMENT STRATEGY CALCULATIONS
--------------------------------------------------------------------------------------*/
.method-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
    align-items: stretch;
}

.info-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: 22px;
    display: flex;
    flex-direction: column;
    height: 100%;
    transition: var(--transition);
}

.info-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.info-card h3 {
    margin: 0 0 12px;
    font-size: 1.08rem;
    line-height: 1.35;
    color: var(--text-main);
}

.info-card p {
    margin: 0 0 12px;
    color: var(--text-muted);
    font-size: 0.96rem;
    line-height: 1.7;
}

.info-card p:last-child {
    margin-top: auto;
    margin-bottom: 0;
}

.info-card strong {
    color: var(--text-main);
    font-weight: 700;
}

/*-------------------------------------------------------------------------------------
                                COMMON INVESTMENT STRATEGY MISTAKES
--------------------------------------------------------------------------------------*/
.mistakes-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
    align-items: stretch;
}

.mistake-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: 22px;
    display: flex;
    flex-direction: column;
    height: 100%;
    transition: var(--transition);
}

.mistake-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.mistake-card h3 {
    margin: 0 0 12px;
    font-size: 1.08rem;
    line-height: 1.35;
    color: var(--text-main);
}

.mistake-card p {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.96rem;
    line-height: 1.7;
}

@media (max-width: 1100px) {
    .mistakes-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 768px) {
    .mistakes-grid {
        grid-template-columns: 1fr;
    }
}

/*-------------------------------------------------------------------------------------
                                            TOOL CARDS
--------------------------------------------------------------------------------------*/
.tool-card,
.info-card,
.step-card,
.benefit-card,
.mistake-card,
.related-card,
.formula-card,
.feature-panel,
.disclaimer-card,
.cta-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.tool-card {
    padding: 22px;
    transition: var(--transition);
}

.tool-card:hover,
.info-card:hover,
.step-card:hover,
.benefit-card:hover,
.mistake-card:hover,
.related-card:hover,
.formula-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.tool-icon {
    width: 48px;
    height: 48px;
    border-radius: 14px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: #e8f0ff;
    color: var(--primary-blue);
    font-size: 1.1rem;
    margin-bottom: 14px;
}

.tool-card h3,
.info-card h3,
.step-card h3,
.benefit-card h3,
.mistake-card h3,
.related-card h3,
.formula-card h3 {
    margin: 0 0 10px;
    font-size: 1.08rem;
    line-height: 1.35;
    color: var(--text-main);
}

.tool-card p,
.info-card p,
.step-card p,
.benefit-card p,
.mistake-card p,
.related-card p,
.formula-card p {
    margin: 0 0 12px;
    color: var(--text-muted);
    font-size: 0.96rem;
}

.tool-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    color: var(--primary-blue);
}

/*-------------------------------------------------------------------------------------
                                         FEATURE / FORMULA
--------------------------------------------------------------------------------------*/
.feature-panel {
    padding: 28px;
}

.formula-grid {
    margin-top: 28px;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
}

.formula-card {
    padding: 22px;
}

.formula-box {
    display: inline-block;
    margin: 8px 0 14px;
    padding: 12px 14px;
    border-radius: 12px;
    background: #eff6ff;
    color: var(--primary-blue-dark);
    font-weight: 800;
    font-size: 1rem;
    overflow-wrap: anywhere;
}

/*-------------------------------------------------------------------------------------
                                           STEP CARDS
--------------------------------------------------------------------------------------*/
.step-card {
    padding: 22px;
    position: relative;
}

.step-number {
    width: 36px;
    height: 36px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--primary-blue);
    color: var(--white);
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 14px;
}

/*-------------------------------------------------------------------------------------
                                        BENEFIT / AUDIENCE
--------------------------------------------------------------------------------------*/
.benefit-card {
    padding: 22px;
}

.benefit-card i {
    font-size: 1.2rem;
    color: var(--primary-blue);
    margin-bottom: 12px;
}

.audience-intro {
    margin: 0 0 24px;
    color: var(--text-muted);
}

.audience-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
}

.audience-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 18px;
    border: 1px solid var(--border-color);
    border-radius: 14px;
    background: var(--white);
    box-shadow: var(--shadow-sm);
}

.audience-item i {
    color: var(--primary-blue);
    font-size: 1rem;
    flex-shrink: 0;
}

.audience-item span {
    font-weight: 600;
    color: var(--text-main);
    font-size: 0.96rem;
}

/*-------------------------------------------------------------------------------------
                                          RELATED CARDS
--------------------------------------------------------------------------------------*/
.related-card {
    display: block;
    padding: 22px;
    transition: var(--transition);
}

.related-card span {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    color: var(--primary-blue);
}

/*-------------------------------------------------------------------------------------
                                               FAQ
--------------------------------------------------------------------------------------*/

.faq-list {
    display: grid;
    gap: 14px;
}

.faq-item {
    border: 1px solid var(--border-color);
    border-radius: 14px;
    background: var(--white);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.faq-item details {
    padding: 0;
}

.faq-item summary {
    list-style: none;
    cursor: pointer;
    padding: 18px 20px;
    font-weight: 700;
    color: var(--text-main);
    position: relative;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: "+";
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--primary-blue);
    font-size: 1.15rem;
    font-weight: 700;
}

.faq-item details[open] summary::after {
    content: "−";
}

.faq-item p {
    margin: 0;
    padding: 0 20px 18px;
    color: var(--text-muted);
}

/*-------------------------------------------------------------------------------------
                                      DISCLAIMER / CTA
--------------------------------------------------------------------------------------*/
.disclaimer-card {
    display: grid;
    grid-template-columns: 60px 1fr;
    gap: 18px;
    padding: 26px;
    align-items: start;
}

.disclaimer-icon {
    width: 52px;
    height: 52px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #e8f0ff;
    color: var(--primary-blue);
    font-size: 1.2rem;
}

.disclaimer-content h2 {
    margin: 0 0 10px;
    font-size: 1.2rem;
}

.disclaimer-content p {
    margin: 0;
    color: var(--text-muted);
}

.cta-card {
    padding: 36px 28px;
    text-align: center;
    background: linear-gradient(180deg, #ffffff 0%, #f8fbff 100%);
}

.cta-card h2 {
    margin: 0 0 12px;
    font-size: clamp(1.7rem, 2.1vw, 2.3rem);
    line-height: 1.2;
}

.cta-card p {
    max-width: 720px;
    margin: 0 auto;
    color: var(--text-muted);
}

.cta-actions {
    margin-top: 24px;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 14px;
}

/*-------------------------------------------------------------------------------------
                                         RESPONSIVE
--------------------------------------------------------------------------------------*/
@media (max-width: 1100px) {
    .page-shell {
        grid-template-columns: 1fr;
    }

    .side-panel {
        position: static;
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .method-grid,
    .steps-grid,
    .benefits-grid,
    .mistakes-grid,
    .related-grid,
    .formula-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 900px) {
    .hero-content,
    .calculator-grid,
    .method-grid,
    .steps-grid,
    .benefits-grid,
    .mistakes-grid,
    .related-grid,
    .formula-grid,
    .audience-grid,
    .side-panel {
        grid-template-columns: 1fr;
    }

    .strategy-hero {
        padding: 38px 0 54px;
    }

    .section-padding {
        padding: 60px 0;
    }

    .hero-text h1 {
        font-size: 2.2rem;
    }
}

@media (max-width: 768px) {
    .method-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .container,
    .narrow-container {
        width: min(100% - 24px, 1200px);
    }

    .section-padding {
        padding: 52px 0;
    }

    .hero-actions,
    .cta-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        width: 100%;
    }

    .feature-panel,
    .tool-card,
    .info-card,
    .step-card,
    .benefit-card,
    .mistake-card,
    .related-card,
    .formula-card,
    .side-card,
    .cta-card,
    .disclaimer-card {
        padding: 20px;
    }

    .disclaimer-card {
        grid-template-columns: 1fr;
    }

    .breadcrumb {
        font-size: 0.82rem;
    }

    .hero-intro,
    .hero-support {
        font-size: 0.98rem;
    }
}