/* ===================================
   KEVIN SOLO-OS Landing Page Styles
   Editorial warm minimal design
   v3.1 - CSS 变量重构
   =================================== */

:root {
    /* Brand */
    --color-dark: #1a1816;
    --color-dark-hover: #2e2b28;
    --color-gold: #a07f4a;
    --color-white: #ffffff;

    /* Text */
    --text-body: #4a4540;
    --text-body-dark: #3d372d;
    --text-muted: #8a7d68;
    --text-muted-dark: #c4bba8;
    --text-subtle: #6b6457;
    --text-hero-sub: #2a2824;
    --text-hero-tag: #5f584d;
    --text-credential: #5c5548;
    --text-evidence-note: #6b6457;
    --text-gold-label: #cdbf9c;
    --text-gold-light: #d4c7a7;
    --text-red: #e8a0a0;
    --text-preview-fade: #8f8778;
    --text-accent-green: #2d6a4f;

    /* Backgrounds */
    --bg-body: #faf8f4;
    --bg-warm: #f5f0e5;
    --bg-light: #fbfaf7;
    --bg-card-dark: rgba(var(--rgb-white), 0.04);
    --bg-card-light: rgba(var(--rgb-white), 0.75);
    --bg-sticky: rgba(var(--rgb-dark), 0.92);

    /* RGB channels for rgba() usage */
    --rgb-dark: 26, 24, 22;
    --rgb-white: 255, 255, 255;
    --rgb-gold: 160, 127, 74;
    --rgb-red: 200, 80, 80;
    --rgb-gold-light: 212, 199, 167;

    /* Radii */
    --radius-card: 16px;
    --radius-card-sm: 12px;
    --radius-card-lg: 20px;
    --radius-badge: 100px;
    --radius-button: 100px;

    /* Shadows */
    --shadow-card: 0 8px 20px rgba(var(--rgb-dark), 0.04);
    --shadow-card-hover: 0 16px 32px rgba(var(--rgb-dark), 0.08);
    --shadow-button: 0 10px 28px rgba(var(--rgb-dark), 0.18);
    --shadow-button-hover: 0 14px 32px rgba(var(--rgb-dark), 0.22);
    --shadow-backtop: 0 4px 14px rgba(var(--rgb-dark), 0.15);

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.75;
    color: var(--color-dark);
    background-color: var(--bg-body);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

/* ===== 文字选择样式 ===== */
::selection {
    background: rgba(var(--rgb-gold), 0.2);
    color: var(--color-dark);
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(48px, 8vw, 72px);
    font-weight: 800;
}

h2 {
    font-size: clamp(32px, 5vw, 44px);
}

h3 {
    font-size: clamp(20px, 3vw, 24px);
}

p {
    margin-bottom: 16px;
    color: var(--text-body);
}

strong {
    font-weight: 700;
    color: var(--color-dark);
}

ul {
    list-style: none;
}

a {
    text-decoration: none;
    color: inherit;
    transition: opacity 0.2s ease;
}

a:hover {
    opacity: 0.85;
}

a:focus-visible {
    outline: 2px solid rgba(var(--rgb-gold), 0.6);
    outline-offset: 4px;
}

.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 clamp(16px, 3vw, 40px);
}

section {
    padding: clamp(60px, 10vh, 100px) 0;
}

.section-label,
.hero-label {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.28em;
    text-transform: uppercase;
    margin-bottom: 20px;
    color: var(--text-muted);
    opacity: 0.9;
    text-align: center;
}

.section-title {
    margin-bottom: 48px;
    max-width: 940px;
    line-height: 1.25;
    text-align: center;
    margin-left: auto;
    margin-right: auto;
}

/* ===== 卡片滚动动画（无 FOUC） ===== */
@keyframes cardFadeIn {
    from {
        opacity: 0;
        transform: translateY(24px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.reveal.visible {
    animation: cardFadeIn 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

/* ===== 固定CTA栏 ===== */
.sticky-cta-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--bg-sticky);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    padding: 14px clamp(16px, 3vw, 40px);
    transform: translateY(-100%);
    transition: transform 0.45s cubic-bezier(0.16, 1, 0.3, 1),
                opacity 0.45s cubic-bezier(0.16, 1, 0.3, 1);
    opacity: 0;
    border-bottom: 1px solid rgba(var(--rgb-white), 0.06);
    contain: layout style;
}

.sticky-cta-bar.visible {
    transform: translateY(0);
    opacity: 1;
}

.sticky-content {
    max-width: 1140px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.sticky-brand {
    font-weight: 800;
    font-size: 18px;
    color: var(--color-white);
    letter-spacing: -0.02em;
}

.sticky-tagline {
    color: var(--text-muted-dark);
    font-size: 13px;
    display: none;
}

@media (min-width: 640px) {
    .sticky-tagline {
        display: block;
    }
}

.sticky-button {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 700;
    color: var(--color-gold);
    background: var(--color-white);
    border: 1.5px solid rgba(var(--rgb-gold), 0.3);
    border-radius: var(--radius-button);
    transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
    white-space: nowrap;
    box-shadow: 0 2px 8px rgba(var(--rgb-dark), 0.06);
}

.sticky-button::after {
    content: " →";
    font-weight: 700;
}

.sticky-button:hover {
    background: var(--color-gold);
    color: var(--color-white);
    border-color: var(--color-gold);
    transform: translateY(-1px);
    box-shadow: 0 6px 18px rgba(var(--rgb-gold), 0.3);
    opacity: 1;
}

/* ===== Hero ===== */
.hero {
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background:
        radial-gradient(ellipse 80% 60% at 50% 0%, rgba(199, 161, 96, 0.12), transparent 50%),
        radial-gradient(ellipse 60% 40% at 70% 20%, rgba(180, 140, 80, 0.08), transparent 40%),
        linear-gradient(180deg, #fdfcf8 0%, #f5f0e6 100%);
    position: relative;
    padding-top: 80px;
    contain: layout style;
}

.hero-enter {
    animation: heroFadeIn 0.8s ease forwards;
}

@keyframes heroFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.hero-title {
    font-size: clamp(56px, 12vw, 104px);
    font-weight: 900;
    letter-spacing: -0.06em;
    line-height: 1.08;
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--color-dark) 0%, #3d3830 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    max-width: 860px;
    margin: 0 auto 20px;
    font-size: clamp(20px, 3vw, 26px);
    font-weight: 600;
    color: var(--text-hero-sub);
    line-height: 1.45;
}

.hero-tagline {
    max-width: 780px;
    margin: 0 auto 44px;
    font-size: clamp(16px, 2.2vw, 19px);
    font-weight: 400;
    color: var(--text-hero-tag);
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 14px;
    flex-wrap: wrap;
    margin-bottom: 40px;
}

/* ===== 价值三要素 ===== */
.value-strip {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 14px;
    margin-top: 40px;
}

.value-item {
    display: flex;
    gap: 14px;
    padding: 20px 22px;
    background: rgba(var(--rgb-white), 0.70);
    border: 1px solid rgba(var(--rgb-dark), 0.06);
    border-radius: 14px;
    text-align: left;
    transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    backdrop-filter: blur(4px);
}

.value-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(var(--rgb-dark), 0.08);
    border-color: rgba(var(--rgb-dark), 0.10);
    opacity: 1;
}

.value-icon {
    font-size: 26px;
    flex-shrink: 0;
    line-height: 1;
}

.value-content strong {
    display: block;
    font-size: 15px;
    font-weight: 700;
    margin-bottom: 4px;
    color: var(--color-dark);
}

.value-content span {
    font-size: 13px;
    color: #6a6358;
    line-height: 1.5;
}

/* ===== Buttons ===== */
.cta-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 16px 36px;
    font-size: 17px;
    font-weight: 700;
    color: var(--color-white);
    background-color: var(--color-dark);
    border: 2px solid var(--color-dark);
    border-radius: var(--radius-button);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow:
        0 10px 32px rgba(var(--rgb-dark), 0.22),
        0 0 0 0 rgba(var(--rgb-gold), 0);
    white-space: nowrap;
}

.cta-button::after {
    content: " →";
    font-weight: 700;
}

.cta-button:hover {
    background-color: var(--color-white);
    color: var(--color-dark);
    transform: translateY(-2px);
    box-shadow:
        0 16px 38px rgba(var(--rgb-dark), 0.28),
        0 0 0 4px rgba(var(--rgb-gold), 0.12);
    opacity: 1;
}

.cta-button:active {
    transform: translateY(0);
}

.cta-button.large {
    padding: 20px 52px;
    font-size: 19px;
}

/* Pulse动画 */
.cta-button.pulse {
    animation: pulse 2.5s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 10px 28px rgba(var(--rgb-dark), 0.18);
    }
    50% {
        box-shadow: 0 10px 28px rgba(var(--rgb-dark), 0.18),
                    0 0 0 8px rgba(var(--rgb-dark), 0.06);
    }
}

.secondary-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 16px 28px;
    font-size: 17px;
    font-weight: 700;
    color: var(--color-dark);
    border: 2px solid rgba(var(--rgb-dark), 0.18);
    border-radius: var(--radius-button);
    background-color: rgba(var(--rgb-white), 0.65);
    backdrop-filter: blur(4px);
    transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
    white-space: nowrap;
}

.secondary-button::after {
    content: " →";
    font-weight: 700;
}

.secondary-button:hover {
    border-color: var(--color-gold);
    background-color: var(--color-white);
    color: var(--color-gold);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(var(--rgb-dark), 0.1);
    opacity: 1;
}

/* ===== Evidence Section ===== */
.evidence-shell {
    background-color: var(--bg-warm);
}

.evidence-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

.evidence-item {
    padding: 28px;
    border-radius: var(--radius-card);
    border: 1px solid rgba(var(--rgb-dark), 0.08);
    background-color: rgba(var(--rgb-white), 0.75);
    box-shadow: 0 8px 20px rgba(var(--rgb-dark), 0.04);
    transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.evidence-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 36px rgba(var(--rgb-dark), 0.10);
    opacity: 1;
}

.evidence-item.featured {
    border-color: rgba(var(--rgb-gold), 0.25);
}

.evidence-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid rgba(var(--rgb-dark), 0.08);
}

.evidence-icon {
    font-size: 22px;
}

.evidence-category {
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-muted);
}

.evidence-list {
    margin: 0;
    padding: 0;
}

.evidence-list li {
    padding: 10px 0;
    padding-left: 18px;
    position: relative;
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-body-dark);
    border-bottom: 1px solid rgba(var(--rgb-dark), 0.05);
}

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

.evidence-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background-color: var(--color-gold);
}

.evidence-cta {
    text-align: center;
}

.evidence-note {
    font-size: 14px;
    color: var(--text-subtle);
    margin-top: 16px;
    margin-bottom: 0;
}

/* ===== Problem Section ===== */
.problem,
.audience {
    background-color: var(--color-dark);
    color: var(--color-white);
}

.problem .section-label,
.audience .section-label {
    color: var(--text-gold-label);
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.problem-item {
    padding: 32px;
    background-color: rgba(var(--rgb-white), 0.04);
    border: 1px solid rgba(var(--rgb-white), 0.08);
    border-radius: var(--radius-card);
    transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
}

.problem-item:hover {
    background-color: rgba(var(--rgb-white), 0.07);
    transform: translateY(-4px);
    border-color: rgba(var(--rgb-white), 0.14);
    opacity: 1;
}

.problem-number {
    font-size: 44px;
    font-weight: 900;
    line-height: 1;
    margin-bottom: 12px;
    opacity: 0.1;
    position: absolute;
    top: 18px;
    right: 22px;
}

.problem-item h3 {
    margin-bottom: 12px;
    font-size: 20px;
    color: var(--color-white);
}

.problem-item p {
    color: var(--text-muted-dark);
    line-height: 1.75;
    font-size: 14px;
    margin-bottom: 0;
}

/* ===== Problem CTA ===== */
.problem-cta {
    margin-top: 48px;
    text-align: center;
}

.problem-cta .cta-button {
    margin-bottom: 14px;
}

.problem-cta-note {
    font-size: 14px;
    color: var(--text-gold-label);
    margin: 0;
}

/* ===== Solution Section ===== */
.solution {
    background-color: var(--bg-warm);
}

.solution-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.solution-item {
    padding: 32px;
    background-color: rgba(var(--rgb-white), 0.75);
    border: 1px solid rgba(var(--rgb-dark), 0.06);
    border-radius: var(--radius-card);
    transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 0 8px 20px rgba(var(--rgb-dark), 0.04);
}

.solution-item:hover {
    border-color: rgba(var(--rgb-dark), 0.12);
    transform: translateY(-3px);
    box-shadow: 0 16px 32px rgba(var(--rgb-dark), 0.08);
    opacity: 1;
}

.solution-icon {
    display: inline-block;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    margin-bottom: 16px;
    padding: 5px 12px;
    background-color: rgba(138, 125, 104, 0.1);
    border-radius: var(--radius-button);
}

.solution-item h3 {
    font-size: 20px;
    margin-bottom: 12px;
    line-height: 1.4;
    color: var(--color-dark);
}

.solution-item p {
    line-height: 1.75;
    margin-bottom: 0;
    font-size: 14px;
    color: var(--text-body);
}

/* ===== Audience Section ===== */
.audience-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    max-width: 800px;
    margin: 0 auto;
}

.audience-item {
    padding: 22px 26px;
    background-color: rgba(var(--rgb-white), 0.04);
    border: 1px solid rgba(var(--rgb-white), 0.08);
    border-radius: var(--radius-card-sm);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.audience-item:hover {
    transform: translateY(-2px);
    opacity: 1;
}

.audience-item.fit {
    border-color: rgba(212, 199, 167, 0.2);
}

.audience-item.unfit {
    border-color: rgba(200, 80, 80, 0.15);
}

.audience-mark {
    display: inline-block;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.08em;
    padding: 4px 10px;
    border-radius: var(--radius-button);
    margin-bottom: 10px;
}

.audience-item.fit .audience-mark {
    background-color: rgba(var(--rgb-white), 0.12);
    color: var(--text-gold-light);
}

.audience-item.unfit .audience-mark {
    background-color: rgba(200, 80, 80, 0.18);
    color: var(--text-red);
}

.audience-item p {
    margin-bottom: 0;
    color: var(--text-muted-dark);
    line-height: 1.65;
    font-size: 14px;
}

.audience-cta {
    margin-top: 40px;
    text-align: center;
}

/* ===== Preview Section ===== */
.preview {
    background-color: var(--color-white);
}

.preview-card {
    max-width: 760px;
    margin: 0 auto;
    padding: 36px;
    border: 1px solid rgba(var(--rgb-dark), 0.08);
    border-radius: var(--radius-card-lg);
    background: var(--bg-light);
    box-shadow: 0 6px 20px rgba(var(--rgb-dark), 0.04);
}

.preview-meta {
    display: flex;
    gap: 10px;
    margin-bottom: 18px;
}

.preview-series {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-muted);
}

.preview-tag {
    font-size: 11px;
    padding: 2px 10px;
    background: rgba(var(--rgb-gold), 0.12);
    color: var(--color-gold);
    border-radius: var(--radius-button);
}

.preview-title {
    font-size: clamp(20px, 3vw, 24px);
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--color-dark);
}

.preview-body {
    font-size: 14px;
    line-height: 1.85;
    color: var(--text-body-dark);
}

.preview-body p {
    margin-bottom: 14px;
}

.preview-list {
    margin: 18px 0 22px 0;
    padding-left: 24px;
}

.preview-list li {
    margin-bottom: 10px;
    padding-left: 8px;
    list-style-type: decimal;
}

.preview-insight {
    background: rgba(var(--rgb-gold), 0.08);
    padding: 14px 18px;
    border-radius: 10px;
    border-left: 3px solid var(--color-gold);
}

.preview-fade {
    margin-top: 20px;
    padding-top: 18px;
    border-top: 1px dashed rgba(var(--rgb-dark), 0.12);
    text-align: center;
}

.preview-fade p {
    color: var(--text-preview-fade);
    font-size: 13px;
    margin-bottom: 18px;
}

.preview-fade .cta-button {
    margin-top: 4px;
}

/* ===== About Kevin Section ===== */
.about-kevin {
    background-color: var(--bg-warm);
}

.about-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 48px;
    align-items: start;
}

.about-text h2 {
    font-size: clamp(26px, 4vw, 32px);
    margin-bottom: 20px;
    color: var(--color-dark);
}

.about-text p {
    font-size: 15px;
    line-height: 1.8;
    color: var(--text-body-dark);
    margin-bottom: 14px;
}

.about-credentials {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.credential-item {
    padding: 22px;
    background: rgba(var(--rgb-white), 0.65);
    border-radius: 14px;
    border: 1px solid rgba(var(--rgb-dark), 0.06);
    text-align: center;
}

.credential-num {
    display: block;
    font-size: 28px;
    font-weight: 800;
    color: var(--color-gold);
    margin-bottom: 6px;
}

.credential-label {
    font-size: 13px;
    color: var(--text-credential);
}

/* ===== How To Section ===== */
.how-to {
    background-color: var(--bg-light);
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.step-item {
    text-align: center;
    padding: 28px 22px;
    background: var(--color-white);
    border-radius: var(--radius-card);
    border: 1px solid rgba(var(--rgb-dark), 0.06);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.step-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 24px rgba(var(--rgb-dark), 0.06);
    opacity: 1;
}

.step-num {
    width: 50px;
    height: 50px;
    margin: 0 auto 18px;
    background: var(--color-dark);
    color: var(--color-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    font-weight: 800;
}

.step-item h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: var(--color-dark);
}

.step-item p {
    color: var(--text-credential);
    font-size: 14px;
    line-height: 1.6;
    margin-bottom: 0;
}

/* ===== Pricing Card ===== */
.pricing {
    background: var(--bg-light);
    text-align: center;
}

.pricing-card {
    max-width: 420px;
    margin: 0 auto;
}

.pricing-card-inner {
    background: var(--color-white);
    border: 1px solid rgba(var(--rgb-dark), 0.08);
    border-radius: var(--radius-card-lg);
    padding: 40px 32px;
    box-shadow: 0 8px 24px rgba(var(--rgb-dark), 0.06);
}

.pricing-header {
    margin-bottom: 24px;
}

.pricing-amount {
    font-size: 48px;
    font-weight: 900;
    color: var(--color-gold);
    letter-spacing: -0.03em;
}

.pricing-period {
    font-size: 16px;
    color: var(--text-muted);
    margin-left: 4px;
}

.pricing-card h3 {
    font-size: 18px;
    margin-bottom: 20px;
    color: var(--color-dark);
}

.pricing-features {
    text-align: left;
    margin-bottom: 28px;
}

.pricing-features li {
    padding: 10px 0;
    padding-left: 24px;
    position: relative;
    font-size: 14px;
    color: var(--text-body-dark);
    border-bottom: 1px solid rgba(var(--rgb-dark), 0.06);
}

.pricing-features li:last-child {
    border-bottom: none;
}

.pricing-features li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--text-accent-green);
    font-weight: 700;
}

.pricing-card .cta-button {
    width: 100%;
}

.pricing-subscribe {
    background-color: var(--color-gold) !important;
    border-color: var(--color-gold) !important;
    color: var(--color-white) !important;
    margin-bottom: 12px;
    box-shadow:
        0 10px 32px rgba(var(--rgb-gold), 0.3),
        0 0 0 0 rgba(var(--rgb-gold), 0) !important;
    animation: shimmer 3s ease-in-out infinite;
}

.pricing-subscribe:hover {
    background-color: var(--color-white) !important;
    color: var(--color-gold) !important;
    border-color: var(--color-gold) !important;
    box-shadow:
        0 16px 38px rgba(var(--rgb-gold), 0.35),
        0 0 0 6px rgba(var(--rgb-gold), 0.1) !important;
    animation: none;
}

@keyframes shimmer {
    0%, 100% {
        box-shadow:
            0 10px 32px rgba(var(--rgb-gold), 0.3),
            0 0 0 0 rgba(var(--rgb-gold), 0);
    }
    50% {
        box-shadow:
            0 10px 32px rgba(var(--rgb-gold), 0.3),
            0 0 0 6px rgba(var(--rgb-gold), 0.08);
    }
}

@keyframes whiteShimmer {
    0%, 100% {
        box-shadow:
            0 10px 36px rgba(255, 255, 255, 0.18),
            0 0 0 0 rgba(255, 255, 255, 0);
    }
    50% {
        box-shadow:
            0 10px 36px rgba(255, 255, 255, 0.18),
            0 0 0 6px rgba(255, 255, 255, 0.05);
    }
}

.pricing-preview {
    display: flex !important;
    width: 100% !important;
    box-sizing: border-box;
}

.pricing-note {
    font-size: 12px;
    color: var(--text-preview-fade);
    margin-top: 14px;
    line-height: 1.5;
}

/* ===== FAQ Section ===== */
.faq {
    background-color: var(--bg-light);
}

/* ===== FAQ Section ===== */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    padding: 26px 0;
    border-bottom: 1px solid rgba(var(--rgb-dark), 0.08);
    transition: all 0.25s ease;
}

.faq-question:hover {
    padding-left: 12px;
    color: var(--color-gold);
}

.faq-question:hover h3 {
    color: var(--color-gold);
}

.faq-question:hover .faq-icon {
    color: var(--color-gold);
    transform: rotate(90deg);
}

.faq-question h3 {
    margin-bottom: 0;
    font-size: clamp(16px, 2.5vw, 18px);
    color: var(--color-dark);
    flex: 1;
    padding-right: 16px;
}

.faq-icon {
    font-size: 22px;
    font-weight: 300;
    color: var(--color-dark);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    min-width: 24px;
    text-align: center;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.16, 1, 0.3, 1),
                padding 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.faq-item.active .faq-answer {
    max-height: 300px;
    padding-bottom: 26px;
}

.faq-answer p {
    font-size: 15px;
    line-height: 1.8;
    color: var(--text-hero-tag);
    margin-bottom: 0;
    padding-top: 6px;
}

.faq-item:last-child .faq-question,
.faq-item:last-child .faq-answer {
    border-bottom: none;
}

.faq-cta {
    margin-top: 40px;
    text-align: center;
}

/* ===== Final CTA ===== */
.final-cta {
    background:
        radial-gradient(ellipse 80% 50% at 50% 0%, rgba(214, 177, 106, 0.18), transparent 50%),
        var(--color-dark);
    color: var(--color-white);
    text-align: center;
}

.cta-title {
    color: var(--color-white);
    margin-bottom: 20px;
    line-height: 1.3;
}

.cta-description {
    font-size: clamp(16px, 2.2vw, 18px);
    margin-bottom: 36px;
    color: var(--text-muted-dark);
    line-height: 1.6;
}

.final-cta .cta-button {
    background-color: var(--color-white);
    color: var(--color-dark);
    border-color: var(--color-white);
    box-shadow:
        0 10px 36px rgba(255, 255, 255, 0.18),
        0 0 0 0 rgba(255, 255, 255, 0);
    animation: whiteShimmer 3s ease-in-out infinite;
}

.final-cta .cta-button:hover {
    background-color: transparent;
    color: var(--color-white);
    border-color: var(--color-white);
    box-shadow:
        0 14px 40px rgba(255, 255, 255, 0.22),
        0 0 0 6px rgba(255, 255, 255, 0.06);
    animation: none;
    opacity: 1;
}

/* ===== Footer ===== */
.footer {
    background-color: var(--bg-warm);
    text-align: center;
    padding: 44px 0;
    border-top: 1px solid rgba(var(--rgb-dark), 0.06);
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}

.footer-brand {
    font-weight: 900;
    font-size: 17px;
    color: var(--color-dark);
    margin-bottom: 0;
}

.footer-tagline {
    color: var(--text-subtle);
    font-size: 13px;
    margin-bottom: 0;
}

/* ===== Progress Bar ===== */
.progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--color-dark), var(--color-gold));
    width: 0%;
    z-index: 1001;
    transition: width 0.1s linear;
}

/* ===== Mobile Bottom CTA Bar (hidden on desktop) ===== */
.mobile-bottom-bar {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(26, 24, 22, 0.94);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 10px 16px;
    z-index: 1000;
    align-items: center;
    gap: 12px;
}

.mobile-bottom-price {
    color: var(--color-white);
    font-size: 12px;
    line-height: 1.3;
    flex-shrink: 0;
}

.mobile-bottom-price strong {
    display: block;
    font-size: 18px;
    color: var(--color-gold);
    font-weight: 800;
}

.mobile-bottom-price strong span {
    font-size: 12px;
    font-weight: 400;
}

.mobile-bottom-btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 44px;
    background: var(--color-gold);
    color: var(--color-white);
    font-size: 16px;
    font-weight: 700;
    border-radius: var(--radius-button);
    box-shadow: 0 6px 22px rgba(var(--rgb-gold), 0.35);
    animation: barPulse 2.5s ease-in-out infinite;
    border: none;
}

@keyframes barPulse {
    0%, 100% { box-shadow: 0 6px 22px rgba(var(--rgb-gold), 0.35); }
    50% { box-shadow: 0 6px 22px rgba(var(--rgb-gold), 0.35), 0 0 0 6px rgba(var(--rgb-gold), 0.08); }
}

/* ===== Back To Top Button ===== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background-color: var(--color-gold);
    color: var(--color-white);
    border: 2px solid var(--color-gold);
    border-radius: var(--radius-button);
    cursor: pointer;
    font-size: 20px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(16px);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 999;
    box-shadow: 0 8px 24px rgba(var(--rgb-gold), 0.25);
}

.back-to-top:hover {
    background-color: var(--color-white);
    color: var(--color-gold);
    border-color: var(--color-gold);
    transform: translateY(-3px);
    box-shadow: 0 12px 30px rgba(var(--rgb-gold), 0.3);
}

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

/* ===== Fade In Animation ===== */
/* 初始可见，无 FOUC；由 JS 触发动画 */
@keyframes sectionFadeIn {
    from {
        opacity: 0;
        transform: translateY(24px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in.visible {
    animation: sectionFadeIn 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

/* ===== Skip Navigation (Accessibility) ===== */
.skip-link {
    position: absolute;
    top: -100%;
    left: 16px;
    z-index: 10000;
    padding: 12px 24px;
    background: var(--color-dark);
    color: var(--color-white);
    font-size: 14px;
    font-weight: 600;
    border-radius: 0 0 8px 8px;
    transition: top 0.2s ease;
}

.skip-link:focus {
    top: 0;
    outline: none;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

/* ===== Scroll Indicator ===== */
.scroll-indicator {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    cursor: pointer;
    z-index: 10;
    opacity: 0.85;
    transition: opacity 0.3s ease;
}

.scroll-indicator:hover {
    opacity: 1;
}

.scroll-arrow {
    font-size: 2.5rem;
    color: #c0392b;
    font-weight: 700;
    line-height: 1;
    animation: bounce 2s ease-in-out infinite;
    display: block;
}

.scroll-text {
    font-size: 0.75rem;
    color: #c0392b;
    margin-top: 6px;
    letter-spacing: 0.08em;
    font-weight: 600;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-8px);
    }
    60% {
        transform: translateY(-4px);
    }
}

/* ===== Responsive - Tablet ===== */
@media (max-width: 1024px) {
    .value-strip {
        grid-template-columns: 1fr;
    }

    .problem-grid,
    .solution-grid,
    .evidence-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .about-credentials {
        flex-direction: row;
        flex-wrap: wrap;
    }

    .credential-item {
        flex: 1;
        min-width: 140px;
    }

    .steps-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }

    .audience-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== Responsive - Mobile ===== */
@media (max-width: 768px) {
    section {
        padding: 56px 0;
    }

    .hero {
        min-height: auto;
        padding: 100px 0 60px;
    }

    .hero-title {
        font-size: clamp(42px, 11vw, 56px);
    }

    .hero-actions {
        flex-direction: column;
        width: 100%;
        max-width: 280px;
        margin-left: auto;
        margin-right: auto;
    }

    .cta-button,
    .secondary-button {
        width: 100%;
        font-size: 16px;
    }

    .cta-button.pulse {
        animation: none;
    }

    .problem-grid,
    .solution-grid,
    .evidence-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .problem-item,
    .solution-item,
    .evidence-item,
    .audience-item {
        padding: 22px;
    }

    .steps-grid {
        grid-template-columns: 1fr;
    }

    .about-credentials {
        flex-direction: column;
    }

    .preview-card {
        padding: 24px;
    }

    .back-to-top {
        bottom: 80px;
        right: 20px;
        width: 42px;
        height: 42px;
        font-size: 16px;
    }

    /* 手机端底部固定 CTA 栏 */
    .sticky-cta-bar {
        display: none !important;
    }

    .mobile-bottom-bar {
        display: flex;
    }

    body {
        padding-bottom: 72px;
    }

    .cta-button,
    .secondary-button,
    .pricing-preview {
        height: 48px;
        font-size: 16px;
    }

    .pricing-subscribe {
        height: 50px;
        font-size: 17px;
    }

}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .reveal.visible,
    .fade-in.visible {
        animation: none;
        opacity: 1;
        transform: none;
    }

    .hero-enter {
        animation: none;
        opacity: 1;
    }
}

/* ===== Touch Device Feedback ===== */
.touch-device .cta-button.touch-active,
.touch-device .secondary-button.touch-active,
.touch-device .sticky-button.touch-active {
    transform: scale(0.98);
    opacity: 0.9;
}

.touch-device .back-to-top.touch-active {
    transform: scale(0.95);
}