*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    background: #0f172a;
}

body {
    min-width: 320px;
    margin: 0;
    overflow-x: hidden;
    color: #cbd5e1;
    background: radial-gradient( circle at 50% -10rem, rgba(14, 165, 233, 0.12), transparent 36rem ), #0f172a;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

a {
    color: inherit;
}

.guide-nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(148, 163, 184, 0.14);
    background: rgba(15, 23, 42, 0.94);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.guide-nav-inner {
    width: min(100% - 32px, 1120px);
    min-height: 64px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 24px;
    margin: 0 auto;
}

.guide-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: #f8fafc;
    font-size: 0.92rem;
    font-weight: 760;
    text-decoration: none;
}

.guide-brand-mark {
    width: 30px;
    height: 30px;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    border: 1px solid rgba(56, 189, 248, 0.4);
    border-radius: 6px;
    color: #38bdf8;
    background: #182334;
    font-size: 0.8rem;
    font-weight: 800;
}

.guide-nav-links {
    display: flex;
    align-items: center;
    gap: 5px;
}

    .guide-nav-links a {
        padding: 9px 11px;
        border-radius: 5px;
        color: #94a3b8;
        font-size: 0.78rem;
        font-weight: 650;
        text-decoration: none;
        transition: color 160ms ease, background 160ms ease;
    }

        .guide-nav-links a:hover {
            color: #e2e8f0;
            background: rgba(148, 163, 184, 0.08);
        }

    .guide-nav-links .guide-nav-cta {
        color: #ffffff;
        background: #0ea5e9;
    }

        .guide-nav-links .guide-nav-cta:hover {
            color: #ffffff;
            background: #0284c7;
        }

.guide-article {
    width: min(100% - 32px, 860px);
    margin: 0 auto;
    padding: 72px 0 90px;
}

.guide-hero {
    max-width: 760px;
    margin: 0 auto 46px;
    text-align: center;
}

.guide-kicker,
.section-number,
.comparison-label {
    display: block;
    color: #38bdf8;
    font-size: 0.68rem;
    font-weight: 820;
    letter-spacing: 0.17em;
}

.guide-hero h1 {
    margin: 14px 0 0;
    color: #f8fafc;
    font-size: clamp(2.5rem, 7vw, 4.7rem);
    line-height: 1;
    letter-spacing: -0.055em;
}

.guide-lead {
    max-width: 680px;
    margin: 24px auto 0;
    color: #a8b5c7;
    font-size: 1.08rem;
    line-height: 1.75;
}

.guide-actions {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 30px;
}

.primary-action,
.secondary-action,
.inline-cta {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    min-height: 45px;
    padding: 0 18px;
    border-radius: 7px;
    font-size: 0.82rem;
    font-weight: 760;
    text-decoration: none;
    transition: transform 160ms ease, background 160ms ease, border-color 160ms ease;
}

.primary-action {
    color: #ffffff;
    background: #0ea5e9;
}

    .primary-action:hover {
        transform: translateY(-2px);
        background: #0284c7;
    }

.secondary-action {
    border: 1px solid rgba(148, 163, 184, 0.2);
    color: #cbd5e1;
    background: #182334;
}

    .secondary-action:hover {
        border-color: rgba(56, 189, 248, 0.45);
    }

.contents-card,
.guide-article > section {
    scroll-margin-top: 86px;
}

.contents-card {
    margin-bottom: 22px;
    padding: 24px;
    border: 1px solid rgba(148, 163, 184, 0.15);
    border-radius: 10px;
    background: #182334;
}

    .contents-card > span {
        display: block;
        margin-bottom: 14px;
        color: #f8fafc;
        font-size: 0.78rem;
        font-weight: 780;
    }

    .contents-card > div {
        display: grid;
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 9px 20px;
    }

    .contents-card a {
        color: #94a3b8;
        font-size: 0.8rem;
        line-height: 1.45;
        text-decoration: none;
    }

        .contents-card a:hover {
            color: #38bdf8;
        }

.guide-article > section:not(.final-cta) {
    margin-top: 22px;
    padding: 38px;
    border: 1px solid rgba(148, 163, 184, 0.15);
    border-radius: 10px;
    background: #1c2738;
}

.guide-article h2 {
    margin: 9px 0 18px;
    color: #f8fafc;
    font-size: clamp(1.65rem, 4vw, 2.25rem);
    line-height: 1.16;
    letter-spacing: -0.03em;
}

.guide-article h3 {
    margin: 28px 0 10px;
    color: #e2e8f0;
    font-size: 1.08rem;
    line-height: 1.35;
}

.guide-article p {
    margin: 0 0 16px;
    color: #9aa8bc;
    font-size: 0.94rem;
    line-height: 1.8;
}

    .guide-article p:last-child {
        margin-bottom: 0;
    }

.tip-card {
    margin-top: 24px;
    padding: 18px;
    border-left: 3px solid #38bdf8;
    background: #182334;
}

    .tip-card strong {
        display: block;
        margin-bottom: 6px;
        color: #e2e8f0;
        font-size: 0.8rem;
    }

    .tip-card p {
        margin: 0;
        font-size: 0.84rem;
    }

.comparison-grid,
.activity-grid {
    display: grid;
    gap: 12px;
    margin: 22px 0;
}

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

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

    .comparison-grid article,
    .activity-grid article {
        padding: 20px;
        border: 1px solid rgba(148, 163, 184, 0.13);
        border-radius: 7px;
        background: #182334;
    }

    .comparison-grid h3,
    .activity-grid h3 {
        margin: 8px 0 9px;
        font-size: 1rem;
    }

    .comparison-grid p,
    .activity-grid p {
        margin: 0;
        font-size: 0.82rem;
        line-height: 1.65;
    }

.rating-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
    margin: 22px 0;
}

    .rating-list div {
        padding: 17px;
        border: 1px solid rgba(148, 163, 184, 0.13);
        border-radius: 7px;
        background: #182334;
    }

    .rating-list strong,
    .rating-list span {
        display: block;
    }

    .rating-list strong {
        color: #e2e8f0;
        font-size: 0.86rem;
    }

    .rating-list span {
        margin-top: 5px;
        color: #94a3b8;
        font-size: 0.78rem;
        line-height: 1.55;
    }

.clean-list,
.steps-list {
    display: grid;
    gap: 11px;
    margin: 20px 0;
    padding: 0;
    list-style: none;
}

    .clean-list li,
    .steps-list li {
        position: relative;
        padding: 14px 16px 14px 38px;
        border: 1px solid rgba(148, 163, 184, 0.12);
        border-radius: 6px;
        color: #9aa8bc;
        background: #182334;
        font-size: 0.86rem;
        line-height: 1.65;
    }

        .clean-list li::before,
        .steps-list li::before {
            position: absolute;
            top: 14px;
            left: 15px;
            color: #38bdf8;
            font-weight: 800;
        }

        .clean-list li::before {
            content: "•";
        }

.steps-list {
    counter-reset: steps;
}

    .steps-list li {
        counter-increment: steps;
    }

        .steps-list li::before {
            content: counter(steps);
            font-size: 0.72rem;
        }

    .clean-list strong,
    .steps-list strong {
        color: #dbe4ef;
    }

.inline-cta {
    margin-top: 7px;
    border: 1px solid rgba(56, 189, 248, 0.28);
    color: #7dd3fc;
    background: rgba(14, 165, 233, 0.06);
}

    .inline-cta:hover {
        border-color: rgba(56, 189, 248, 0.5);
        background: rgba(14, 165, 233, 0.11);
    }

.final-cta {
    margin-top: 50px;
    padding: 48px;
    border: 1px solid rgba(56, 189, 248, 0.22);
    border-radius: 10px;
    text-align: center;
    background: linear-gradient( 145deg, rgba(14, 165, 233, 0.09), rgba(28, 39, 56, 0.96) 55% );
}

    .final-cta h2 {
        max-width: 620px;
        margin: 12px auto 0;
    }

    .final-cta p {
        max-width: 600px;
        margin: 18px auto 26px;
    }

.guide-footer {
    width: min(100% - 32px, 1120px);
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    gap: 32px;
    margin: 0 auto;
    padding: 28px 0 40px;
    border-top: 1px solid rgba(148, 163, 184, 0.14);
}

    .guide-footer p {
        max-width: 430px;
        margin: 12px 0 0;
        color: #64748b;
        font-size: 0.78rem;
        line-height: 1.6;
    }

.guide-footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

    .guide-footer-links a {
        color: #94a3b8;
        font-size: 0.76rem;
        text-decoration: none;
    }

        .guide-footer-links a:hover {
            color: #38bdf8;
        }

.guide-back-to-top {
    position: fixed;
    right: 24px;
    bottom: 24px;
    z-index: 1000;
    width: 46px;
    height: 46px;
    border: 1px solid rgba(56, 189, 248, 0.28);
    border-radius: 50%;
    color: #38bdf8;
    background: rgba(24, 35, 52, 0.95);
    font: inherit;
    font-size: 1.05rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: opacity 180ms ease, visibility 180ms ease, transform 180ms ease, background 180ms ease;
}

    .guide-back-to-top.is-visible {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }

    .guide-back-to-top:hover {
        color: #ffffff;
        background: #0ea5e9;
    }

@media (max-width: 760px) {
    .guide-nav-links a:not(.guide-nav-cta) {
        display: none;
    }

    .guide-article {
        padding-top: 52px;
    }

    .contents-card > div,
    .comparison-grid,
    .activity-grid,
    .rating-list {
        grid-template-columns: 1fr;
    }

    .guide-footer {
        align-items: flex-start;
        flex-direction: column;
    }
}

@media (max-width: 520px) {
    .guide-article {
        width: min(100% - 24px, 860px);
        padding: 42px 0 70px;
    }

    .guide-hero h1 {
        font-size: clamp(2.25rem, 13vw, 3.25rem);
    }

    .guide-lead {
        font-size: 0.97rem;
    }

    .guide-actions {
        display: grid;
    }

    .primary-action,
    .secondary-action {
        width: 100%;
    }

    .contents-card {
        padding: 20px;
    }

    .guide-article > section:not(.final-cta) {
        padding: 28px 20px;
    }

    .final-cta {
        padding: 36px 20px;
    }

    .guide-back-to-top {
        right: max(16px, env(safe-area-inset-right));
        bottom: max(16px, env(safe-area-inset-bottom));
        width: 44px;
        height: 44px;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
    }
}


/* =====================================================
   GUIDE ACCORDION
   ===================================================== */

.guide-accordion {
    display: grid;
    gap: 10px;
    margin-top: 22px;
}

.guide-accordion-item {
    scroll-margin-top: 86px;
    overflow: hidden;
    border: 1px solid rgba(148, 163, 184, 0.15);
    border-radius: 9px;
    background: #1c2738;
    transition: border-color 180ms ease, background 180ms ease;
}

    .guide-accordion-item:hover,
    .guide-accordion-item.is-open {
        border-color: rgba(56, 189, 248, 0.34);
    }

    .guide-accordion-item.is-open {
        background: #1a2637;
    }

.guide-accordion-heading {
    margin: 0;
}

.guide-accordion-button {
    width: 100%;
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
    gap: 16px;
    padding: 20px 22px;
    border: 0;
    color: inherit;
    background: transparent;
    font: inherit;
    text-align: left;
    cursor: pointer;
    transition: background 180ms ease, color 180ms ease;
}

    .guide-accordion-button:hover {
        background: rgba(148, 163, 184, 0.035);
    }

    .guide-accordion-button:focus-visible {
        outline: 2px solid #38bdf8;
        outline-offset: -3px;
    }

.guide-accordion-number {
    min-width: 30px;
    color: #38bdf8;
    font-size: 0.66rem;
    font-weight: 820;
    letter-spacing: 0.14em;
}

.guide-accordion-title {
    color: #f8fafc;
    font-size: 1rem;
    font-weight: 760;
    line-height: 1.4;
}

.guide-accordion-chevron {
    flex-shrink: 0;
    color: #64748b;
    transition: transform 240ms ease, color 180ms ease;
}

.guide-accordion-item.is-open
.guide-accordion-chevron {
    color: #38bdf8;
    transform: rotate(180deg);
}

.guide-accordion-panel {
    display: grid;
    grid-template-rows: 0fr;
    visibility: hidden;
    transition: grid-template-rows 320ms ease, visibility 320ms;
}

.guide-accordion-item.is-open
.guide-accordion-panel {
    grid-template-rows: 1fr;
    visibility: visible;
}

.guide-accordion-content {
    min-height: 0;
    overflow: hidden;
    padding: 0 22px;
}

.guide-accordion-item.is-open
.guide-accordion-content {
    padding-bottom: 28px;
}

.guide-accordion-content h3 {
    margin-top: 24px;
}

.guide-accordion-content p:first-child {
    margin-top: 2px;
}

@media (max-width: 520px) {
    .guide-accordion-button {
        gap: 12px;
        padding: 18px 16px;
    }

    .guide-accordion-number {
        min-width: 26px;
    }

    .guide-accordion-title {
        font-size: 0.92rem;
    }

    .guide-accordion-content {
        padding: 0 16px;
    }

    .guide-accordion-item.is-open
    .guide-accordion-content {
        padding-bottom: 22px;
    }
}


/* =====================================================
   QUICK DIAGNOSTIC CARD
   ===================================================== */

.diagnostic-card {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(220px, 0.9fr);
    gap: 20px 28px;
    margin: 22px 0 0;
    padding: 26px;
    border: 1px solid rgba(56, 189, 248, 0.2);
    border-radius: 10px;
    background: linear-gradient( 145deg, rgba(14, 165, 233, 0.08), rgba(24, 35, 52, 0.96) 62% );
}

.diagnostic-kicker {
    display: block;
    margin-bottom: 8px;
    color: #38bdf8;
    font-size: 0.62rem;
    font-weight: 820;
    letter-spacing: 0.15em;
}

.diagnostic-card h2 {
    margin: 0;
    color: #f8fafc;
    font-size: 1.35rem;
    line-height: 1.3;
    letter-spacing: -0.025em;
}

.diagnostic-card ol {
    display: grid;
    gap: 7px;
    margin: 0;
    padding: 0;
    counter-reset: diagnostic;
    list-style: none;
}

.diagnostic-card li {
    position: relative;
    padding: 9px 10px 9px 34px;
    border: 1px solid rgba(148, 163, 184, 0.11);
    border-radius: 5px;
    color: #cbd5e1;
    background: rgba(15, 23, 42, 0.42);
    font-size: 0.77rem;
    line-height: 1.5;
    counter-increment: diagnostic;
}

    .diagnostic-card li::before {
        content: counter(diagnostic);
        position: absolute;
        top: 9px;
        left: 12px;
        color: #38bdf8;
        font-size: 0.68rem;
        font-weight: 820;
    }

.diagnostic-card > p {
    grid-column: 1 / -1;
    margin: 0;
    color: #8796aa;
    font-size: 0.8rem;
    line-height: 1.65;
}

@media (max-width: 680px) {
    .diagnostic-card {
        grid-template-columns: 1fr;
    }

        .diagnostic-card > p {
            grid-column: auto;
        }
}

@media (max-width: 520px) {
    .diagnostic-card {
        padding: 20px;
    }

        .diagnostic-card h2 {
            font-size: 1.18rem;
        }
}