:root {
    --brand: #3C83F6;
    --bg: #070a13;
    --bg-alt: #0b111e;
    --card: #111827;
    --text: #f8fafc;
    --muted: #94a3b8;
    --border: rgba(148, 163, 184, .22);
    --ok: #25D366;

    /* ── Layout width ── change here to switch A / B ──────────────── */
    /* Layout A · Conservative（稳妥） */
    /* --container-max: 1280px; */
    /* --container-pad: clamp(16px, 2.2vw, 28px); */

    /* Layout B · Balanced wide-screen（兼顾大屏观感） */
    --container-max: 1520px;
    --container-pad: clamp(16px, 2vw, 28px);
}

[data-theme="light"] {
    --bg: #f7f9fe;
    --bg-alt: #edf3ff;
    --card: #ffffff;
    --text: #0b1730;
    --muted: #2f4664;
    --border: rgba(43, 84, 150, .30)
}

* {
    box-sizing: border-box
}

html,
body {
    margin: 0;
    padding: 0
}

body {
    font-family: Inter, Segoe UI, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6
}

html {
    scroll-behavior: smooth
}

a {
    text-decoration: none;
    color: inherit
}

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-pad)
}

.section {
    padding: 88px 0
}

.section:not(.hero) {
    content-visibility: auto;
    contain-intrinsic-size: 960px
}

.alt {
    background: var(--bg-alt)
}

.required-star {
    color: #ef4444;
    font-weight: 700
}

h1,
h2,
h3,
h4 {
    line-height: 1.15;
    letter-spacing: -.02em
}

h2 {
    font-size: clamp(28px, 4vw, 44px);
    margin: 0 0 10px
}

.center {
    text-align: center
}

.nav {
    position: fixed;
    left: 0;
    right: 0;
    top: 0;
    height: 72px;
    z-index: 100;
    background: color-mix(in srgb, var(--bg) 92%, transparent);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border)
}

.nav-inner {
    height: 72px;
    display: flex;
    justify-content: space-between;
    align-items: center
}

.logo {
    height: 28px;
    width: auto;
    filter: drop-shadow(0 1px 1px rgba(0, 0, 0, .35))
}

[data-theme="light"] .logo {
    filter: brightness(0) saturate(100%) invert(39%) sepia(97%) saturate(1732%) hue-rotate(204deg) brightness(100%) contrast(94%) drop-shadow(0 1px 1px rgba(255, 255, 255, .25))
}

.logo-fallback {
    display: none;
    font-size: 24px;
    font-weight: 800;
    letter-spacing: .04em;
    color: #ffffff;
    line-height: 1
}

[data-theme="light"] .logo-fallback {
    color: #0b1730
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 10px
}

.top-cta {
    height: 40px;
    padding: 0 18px;
    border-radius: 10px;
    background: #1d4ed8;
    color: #fff;
    font-weight: 700;
    font-size: 13px;
    display: inline-flex;
    align-items: center
}

[data-theme="light"] .nav {
    background: #ffffff;
    backdrop-filter: none
}

.hero {
    padding-top: 130px;
    min-height: 96vh;
    display: flex;
    align-items: center;
    background: radial-gradient(circle at 12% 8%, rgba(60, 131, 246, .18), transparent 40%), linear-gradient(90deg, rgba(5, 12, 26, .98) 0%, rgba(4, 10, 22, .95) 48%, rgba(3, 8, 19, .9) 100%)
}

.hero-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(520px, 640px);
    gap: clamp(32px, 4vw, 72px);
    align-items: center
}

.hero-grid> :first-child {
    max-width: 700px
}

.pill {
    display: inline-block;
    padding: 7px 14px;
    border-radius: 999px;
    color: var(--brand);
    border: 1px solid color-mix(in srgb, var(--brand) 40%, transparent);
    font-size: 11px;
    letter-spacing: .14em;
    text-transform: uppercase
}

.hero-from {
    font-size: 14px;
    color: var(--muted);
    letter-spacing: .1em;
    text-transform: uppercase;
    margin: 14px 0 12px
}

.hero-from strong {
    color: var(--text)
}

h1 {
    font-size: clamp(34px, 6vw, 64px);
    margin: 0 0 18px;
    max-width: 12ch;
    text-wrap: balance
}

.hero-sub {
    font-size: 20px;
    color: var(--muted);
    max-width: 34ch;
    margin: 0 0 28px
}

.hero-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap
}

.btn {
    height: 48px;
    padding: 0 22px;
    border-radius: 10px;
    font-weight: 700;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: none;
    cursor: pointer
}

.btn-primary {
    background: #1d4ed8;
    color: #fff
}

.btn-wa {
    background: #22c55e;
    color: #fff
}

.hero-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 18px;
    padding: 18px;
    width: 100%;
    max-width: 700px;
    justify-self: end;
    position: relative;
    overflow: hidden;
    isolation: isolate;
    box-shadow: 0 24px 80px rgba(0, 0, 0, .28)
}

.hero-card::before {
    content: "";
    position: absolute;
    inset: -20% auto auto -12%;
    width: 240px;
    height: 240px;
    border-radius: 999px;
    background: radial-gradient(circle, rgba(60, 131, 246, .22) 0%, rgba(60, 131, 246, 0) 72%);
    z-index: -1;
    pointer-events: none
}

.hero-media {
    aspect-ratio: 16/9;
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--border);
    background: #060c18
}

.hero-media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: .88
}

.anchor-target,
.card[id],
.section[id] {
    scroll-margin-top: 104px
}

.chips {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 12px
}

.anchor-target {
    position: relative;
    top: -104px;
    display: block;
    width: 1px;
    height: 1px;
    pointer-events: none;
    visibility: hidden
}

.chips span {
    font-size: 11px;
    padding: 5px 10px;
    border-radius: 999px;
    color: var(--brand);
    border: 1px solid color-mix(in srgb, var(--brand) 35%, transparent);
    background: color-mix(in srgb, var(--brand) 12%, transparent)
}

[data-theme="light"] .hero-media img {
    opacity: 1
}

[data-theme="light"] .hero {
    background: radial-gradient(circle at 10% 0, rgba(60, 131, 246, .20), rgba(60, 131, 246, .05) 45%, transparent 70%)
}

[data-theme="light"] .alt {
    background: linear-gradient(180deg, #edf3ff 0%, #f5f8ff 100%)
}

[data-theme="light"] .chips span {
    background: color-mix(in srgb, var(--brand) 14%, #ffffff)
}


.profit-equation {
    color: var(--brand);
    line-height: 1.7
}

.profit-equation .eq-positive {
    color: #22c55e
}

.profit-equation .eq-risk {
    color: #f97316
}

.profit-equation .eq-cost {
    color: #60a5fa
}

.profit-equation .eq-plus {
    color: var(--muted)
}

[data-theme="light"] .profit-equation .eq-positive {
    color: #15803d
}

[data-theme="light"] .profit-equation .eq-risk {
    color: #c2410c
}

[data-theme="light"] .profit-equation .eq-cost {
    color: #1d4ed8
}

.profit-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 14px
}

.card,
.card-lite {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 20px
}

.card small {
    display: block;
    color: var(--muted);
    font-size: 12px;
    letter-spacing: .08em;
    text-transform: uppercase;
    margin-bottom: 8px
}

.card h3 {
    margin: 0 0 16px;
    font-size: 21px
}

.card ul,
.card-lite ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 7px;
    color: var(--muted);
    font-size: 14px
}

.card ul li::before,
.card-lite ul li::before {
    content: "→ ";
    color: var(--brand)
}

.visual {
    margin-top: 12px;
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 10px;
    background: color-mix(in srgb, var(--bg-alt) 68%, transparent)
}

.visual-photo {
    padding: 0;
    overflow: hidden;
    aspect-ratio: 16/10
}

.visual-photo img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover
}

.formula {
    margin-top: 18px;
    border: 1px solid color-mix(in srgb, var(--brand) 40%, transparent);
    border-radius: 14px;
    padding: 22px;
    text-align: center;
    background: linear-gradient(135deg, rgba(60, 131, 246, .1), rgba(60, 131, 246, .03))
}

.formula p {
    margin: 4px 0;
    font-size: clamp(18px, 2.3vw, 28px);
    font-weight: 800
}

.three-col {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 14px
}

.card-lite h3 {
    margin: 0 0 16px;
    font-size: 20px
}

.comparison-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
    gap: 24px;
    width: 100%;
    margin: 0;
    align-items: center
}

.comp-col {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 16px;
    overflow: hidden;
    min-width: 0
}

.comparison-vs {
    height: 44px;
    width: 44px;
    justify-self: center;
    border-radius: 999px;
    border: 1px solid color-mix(in srgb, var(--brand) 45%, transparent);
    background: color-mix(in srgb, var(--brand) 14%, var(--bg));
    color: var(--brand);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: .06em;
    display: inline-flex;
    align-items: center;
    justify-content: center
}

.comp-bad {
    opacity: .85
}

.comp-good {
    border-color: var(--brand);
    box-shadow: 0 12px 32px color-mix(in srgb, var(--brand) 12%, transparent);
    transform: translateY(-4px);
    position: relative;
    z-index: 1
}

.comp-header {
    padding: 20px;
    font-size: 20px;
    font-weight: 700;
    text-align: center;
    border-bottom: 1px solid var(--border)
}

.comp-bad .comp-header {
    background: color-mix(in srgb, #ef4444 8%, transparent);
    color: #f87171
}

.comp-good .comp-header {
    background: color-mix(in srgb, var(--brand) 12%, transparent);
    color: var(--brand)
}

.comp-list {
    list-style: none;
    margin: 0;
    padding: 24px
}

.comp-list li {
    padding: 14px 0;
    display: flex;
    align-items: center;
    gap: 14px;
    border-bottom: 1px solid color-mix(in srgb, var(--border) 60%, transparent);
    color: var(--text);
    font-size: 16px;
    font-weight: 500
}

.comp-list li:last-child {
    border-bottom: none
}

.comp-list .bad-icon,
.comp-list .good-icon {
    font-size: 20px
}

.comparison-sub {
    max-width: 920px;
    margin: 0 auto 28px;
    color: var(--muted);
    font-size: clamp(12px, .9vw, 16px);
    line-height: 1.5;
    font-weight: 600
}

.hp-field {
    position: absolute !important;
    left: -10000px !important;
    width: 1px;
    height: 1px;
    overflow: hidden
}

.faq {
    max-width: 860px
}

.faq details {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 14px 16px
}

.faq details+details {
    margin-top: 10px
}

.faq summary {
    cursor: pointer;
    font-weight: 700
}

.faq p {
    margin: 8px 0 0;
    color: var(--muted)
}

.form-wrap {
    max-width: 760px
}

.form-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 22px
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px
}

.form-grid label {
    display: block;
    font-size: 12px;
    color: var(--muted);
    letter-spacing: .06em;
    text-transform: uppercase
}

.form-grid input,
.form-grid select {
    display: block;
    margin-top: 6px;
    width: 100%;
    height: 44px;
    border-radius: 10px;
    border: 1px solid var(--border);
    background: color-mix(in srgb, var(--card) 84%, #fff 2%);
    color: var(--text);
    padding: 0 12px
}

.form-grid input[list] {
    padding-right: 12px
}

.form-grid .full {
    grid-column: 1/-1
}

.submit-btn {
    margin-top: 12px;
    width: 100%
}

.msg {
    margin-top: 8px;
    font-size: 12px;
    text-align: center
}

.error {
    color: #ef4444
}

.ok {
    color: #22c55e
}

.field-error {
    display: block;
    font-size: 11px;
    color: #f87171;
    margin-top: 5px;
    padding: 4px 8px;
    border-radius: 6px;
    background: color-mix(in srgb, #ef4444 12%, transparent);
    border: 1px solid color-mix(in srgb, #ef4444 25%, transparent);
}

.field-error[hidden] {
    display: none;
}

.form-grid input.is-invalid,
.form-grid select.is-invalid {
    border-color: #ef4444;
    outline: none;
    box-shadow: 0 0 0 1px color-mix(in srgb, #ef4444 18%, transparent);
}

.footer {
    padding: 22px 0 100px;
    border-top: 1px solid var(--border)
}

.footer-stack {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px
}

.footer-trust {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    justify-content: center;
    color: #89b3e5;
    font-size: 13px
}

.trust-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap
}

.trust-icon {
    font-size: 12px;
    line-height: 1
}

.trust-divider {
    color: color-mix(in srgb, #89b3e5 60%, transparent)
}

.footer-copy {
    margin: 0;
    text-align: center;
    color: #a7c0df;
    font-size: 13px
}

.footer {
    content-visibility: auto;
    contain-intrinsic-size: 180px
}

.theme-btn {
    height: 40px;
    min-width: 40px;
    padding: 0 10px;
    border: 1px solid var(--border);
    background: transparent;
    border-radius: 10px;
    color: var(--text);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0
}

.theme-btn .icon-moon {
    display: none
}

[data-theme="dark"] .theme-btn .icon-sun {
    display: none
}

[data-theme="dark"] .theme-btn .icon-moon {
    display: inline
}

.thumb-cta {
    display: none
}

.zoomable-image {
    cursor: zoom-in
}

.image-lightbox {
    position: fixed;
    inset: 0;
    z-index: 300;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 16px;
    background: color-mix(in srgb, var(--bg) 88%, transparent)
}

.image-lightbox.is-open {
    display: flex
}

.image-lightbox img {
    max-width: min(96vw, 1200px);
    max-height: 90vh;
    width: auto;
    height: auto;
    border-radius: 12px;
    border: 1px solid var(--border);
    background: var(--card)
}

.image-lightbox-close {
    position: absolute;
    top: 14px;
    right: 14px;
    height: 40px;
    width: 40px;
    border-radius: 10px;
    border: 1px solid var(--border);
    background: var(--card);
    color: var(--text);
    font-size: 24px;
    line-height: 1;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center
}

body.lightbox-open {
    overflow: hidden
}

@media (min-width:981px) {

    .hero {
        min-height: clamp(720px, 88vh, 920px)
    }

    h1 {
        font-size: clamp(44px, 4.2vw, 72px)
    }

    #profit .visual-photo,
    #stability .visual-photo {
        aspect-ratio: 16/10;
        height: auto
    }

    #profit .card,
    #stability .card-lite {
        display: flex;
        flex-direction: column
    }

    #profit .visual,
    #stability .visual {
        margin-top: auto
    }
}

@media (min-width:1440px) {

    .section {
        padding: 104px 0
    }

    .section>.container,
    .section .container {
        width: 100%
    }

    .hero-grid {
        grid-template-columns: minmax(0, 1fr) minmax(620px, 760px);
        gap: clamp(44px, 5vw, 96px)
    }

    .hero-grid> :first-child {
        padding-right: 8px
    }

    h1 {
        font-size: clamp(56px, 4.4vw, 82px)
    }

    .hero-sub {
        font-size: 22px
    }

    .hero-card {
        padding: 20px 20px 18px;
        border-radius: 22px
    }

    .hero-media {
        border-radius: 16px
    }

    .chips {
        gap: 10px
    }

    .chips span {
        font-size: 11px;
        letter-spacing: .01em
    }

    .profit-grid,
    .three-col,
    .comparison-grid {
        gap: 20px
    }

    .card,
    .card-lite {
        padding: 24px
    }

    .card h3,
    .card-lite h4 {
        font-size: 24px
    }

    .card ul,
    .card-lite ul {
        font-size: 15px;
        gap: 9px
    }

    .comparison-sub {
        margin-bottom: 36px;
        font-size: clamp(14px, .95vw, 18px)
    }

    .formula {
        margin-top: 24px;
        padding: 24px 28px
    }

    .faq {
        max-width: 980px
    }

    .faq details {
        padding: 18px 20px
    }

    .form-wrap {
        max-width: 860px
    }
}

@media (min-width:1800px) {

    :root {
        --container-max: 1600px;
    }

    .hero-grid {
        grid-template-columns: minmax(0, 1fr) 780px;
        gap: 88px
    }

    .hero-grid> :first-child {
        max-width: 760px
    }

    h1 {
        font-size: 84px
    }

    .profit-grid,
    .three-col,
    .comparison-grid {
        gap: 24px
    }

    .card,
    .card-lite,
    .comp-list,
    .comp-header {
        font-size: inherit
    }
}

@media (max-width:980px) {

    .hero-grid,
    .three-col,
    .comparison-grid {
        grid-template-columns: 1fr
    }

    .profit-grid {
        grid-template-columns: 1fr
    }

    .top-cta {
        display: none
    }
}

@media (max-width:767px) {
    body {
        padding-bottom: 88px;
        font-size: 18px
    }

    h2 {
        font-size: 32px
    }

    .hero-sub {
        font-size: 20px
    }

    .card ul,
    .card-lite ul,
    .faq p {
        font-size: 17px
    }

    .form-grid {
        grid-template-columns: 1fr
    }

    .hero-actions {
        justify-content: flex-end
    }

    .thumb-cta {
        position: fixed;
        left: 10px;
        right: 10px;
        bottom: 10px;
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 10px;
        z-index: 180;
        background: color-mix(in srgb, var(--bg) 88%, transparent);
        border: 1px solid var(--border);
        border-radius: 14px;
        padding: 10px;
        backdrop-filter: blur(8px);
        opacity: 0;
        transform: translateY(10px);
        pointer-events: none;
        transition: opacity .2s ease, transform .2s ease
    }

    .thumb-cta.is-visible {
        opacity: 1;
        transform: translateY(0);
        pointer-events: auto
    }

    .thumb-cta a {
        height: 44px;
        border-radius: 10px;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 14px;
        font-weight: 800
    }

    .thumb-cta .primary {
        background: var(--brand);
        color: #fff
    }

    .thumb-cta.wa-only {
        grid-template-columns: 1fr
    }

    .thumb-cta.wa-only .primary {
        display: none
    }

    .thumb-cta .wa {
        background: var(--ok);
        color: #fff
    }

    .footer-trust {
        row-gap: 6px;
        column-gap: 10px;
        font-size: 12px
    }

    .trust-divider {
        display: none
    }

    .footer-copy {
        font-size: 12px
    }
}

[data-theme="light"] .thumb-cta {
    background: #ffffff;
    backdrop-filter: none
}

[data-theme="light"] .footer-trust {
    color: #2b64a5
}

[data-theme="light"] .trust-divider {
    color: color-mix(in srgb, #2b64a5 55%, transparent)
}

[data-theme="light"] .footer-copy {
    color: #355f93
}

[data-theme="light"] .card ul,
[data-theme="light"] .card-lite ul,
[data-theme="light"] .faq p {
    color: #1f3148
}

[data-theme="light"] .visual,
[data-theme="light"] .form-grid input,
[data-theme="light"] .form-grid select {
    background: #ffffff
}