/* ============================================
   知源题库 KnowSource — 宣发页面样式
   ============================================ */

/* --- CSS 变量 --- */
:root {
    /* 品牌色 */
    --color-primary: #667eea;
    --color-primary-dark: #5a6fd6;
    --color-secondary: #764ba2;
    --color-accent: #7c5ce7;

    /* 渐变 */
    --gradient-brand: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-brand-soft: linear-gradient(135deg, rgba(102, 126, 234, 0.08) 0%, rgba(118, 75, 162, 0.08) 100%);
    --gradient-hero: linear-gradient(160deg, #667eea 0%, #764ba2 60%, #4a3f8a 100%);

    /* 中性色 */
    --color-bg: #ffffff;
    --color-bg-alt: #f8f9fc;
    --color-bg-dark: #1a1a2e;
    --color-text: #1e293b;
    --color-text-secondary: #64748b;
    --color-text-tertiary: #94a3b8;
    --color-border: #e2e8f0;
    --color-border-light: #f1f5f9;

    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 4px 10px -6px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 20px 40px -10px rgba(0, 0, 0, 0.1), 0 8px 20px -10px rgba(0, 0, 0, 0.06);
    --shadow-glow: 0 0 30px rgba(102, 126, 234, 0.25);

    /* 字体 */
    --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;

    /* 字号 */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
    --text-5xl: 3rem;
    --text-6xl: 3.75rem;

    /* 间距 */
    --space-section: 6rem;

    /* 圆角 */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-3xl: 2rem;

    /* 过渡 */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 400ms cubic-bezier(0.16, 1, 0.3, 1);
}

/* --- Reset & Base --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--color-text);
    background: var(--color-bg);
    overflow-x: hidden;
}

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

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

ul {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* --- Container --- */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* --- Section Header --- */
.section-header {
    text-align: center;
    margin-bottom: 3.5rem;
}

.section-label {
    display: inline-block;
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-primary);
    background: rgba(102, 126, 234, 0.1);
    padding: 0.3rem 0.75rem;
    border-radius: 100px;
    margin-bottom: 1rem;
}

.section-title {
    font-size: var(--text-4xl);
    font-weight: 800;
    letter-spacing: -0.02em;
    line-height: 1.2;
    color: var(--color-text);
    margin-bottom: 0.75rem;
}

.section-subtitle {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    max-width: 480px;
    margin: 0 auto;
}

/* ==========================================
   导航栏
   ========================================== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    transition: background var(--transition-base), box-shadow var(--transition-base);
}

.nav.scrolled {
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
    border-bottom: 1px solid var(--color-border-light);
}

.nav.scrolled .nav-logo {
    color: var(--color-text);
}

.nav.scrolled .nav-links a {
    color: var(--color-text-secondary);
}

.nav.scrolled .nav-links a:hover {
    color: var(--color-primary);
}

.nav.scrolled .nav-cta {
    color: #fff;
    background: var(--gradient-brand);
}

.nav.scrolled .nav-toggle span {
    background: var(--color-text);
}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    font-weight: 700;
    font-size: var(--text-lg);
    color: #ffffff;
    transition: color var(--transition-base);
}

.nav-logo:hover {
    opacity: 0.8;
}

.nav-logo-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    font-size: var(--text-sm);
    font-weight: 500;
    color: rgba(255, 255, 255, 0.75);
    transition: color var(--transition-fast);
}

.nav-links a:hover {
    color: #ffffff;
}

.nav-cta {
    display: inline-flex;
    align-items: center;
    padding: 0.5rem 1.25rem;
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text);
    background: #ffffff;
    border-radius: 100px;
    transition: opacity var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.nav-cta:hover {
    opacity: 0.9;
    transform: translateY(-1px);
    box-shadow: var(--shadow-glow);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: #ffffff;
    border-radius: 2px;
    transition: transform var(--transition-fast), opacity var(--transition-fast), background var(--transition-base);
}

/* ==========================================
   Hero 区域
   ========================================== */
.hero {
    position: relative;
    min-height: 100dvh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 6rem 1.5rem 4rem;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.hero-gradient {
    position: absolute;
    inset: 0;
    background: var(--gradient-hero);
    opacity: 0.95;
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
    background-size: 60px 60px;
}

.hero-container {
    position: relative;
    z-index: 1;
    display: flex;
    align-items: center;
    gap: 3rem;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.hero-inner {
    position: relative;
    z-index: 1;
    max-width: 560px;
    flex-shrink: 0;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: var(--text-xs);
    font-weight: 600;
    color: rgba(255, 255, 255, 0.8);
    background: rgba(255, 255, 255, 0.12);
    padding: 0.4rem 0.9rem;
    border-radius: 100px;
    margin-bottom: 2rem;
    backdrop-filter: blur(10px);
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    color: #ffffff;
    margin-bottom: 1.5rem;
}

.hero-highlight {
    background: linear-gradient(90deg, #fbbf24, #f59e0b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: var(--text-lg);
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
    margin-bottom: 2.5rem;
}

.hero-desc strong {
    color: #ffffff;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 3rem;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.75rem;
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--color-text);
    background: #ffffff;
    border-radius: 100px;
    transition: all var(--transition-fast);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    padding: 0.75rem 1.75rem;
    font-size: var(--text-base);
    font-weight: 600;
    color: #ffffff;
    border: 1.5px solid rgba(255, 255, 255, 0.3);
    border-radius: 100px;
    transition: all var(--transition-fast);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
}

.btn-large {
    padding: 1rem 2.5rem;
    font-size: var(--text-lg);
}

.hero-stats {
    display: flex;
    gap: 2.5rem;
}

.hero-stat {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.hero-stat-num {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: #ffffff;
    font-variant-numeric: tabular-nums;
}

.hero-stat-label {
    font-size: var(--text-sm);
    color: rgba(255, 255, 255, 0.65);
}

/* Hero Visual — 模拟界面 */
.hero-visual {
    flex-shrink: 0;
    display: none;
}

@media (min-width: 1024px) {
    .hero-visual {
        display: block;
    }
}

.hero-mockup {
    width: 480px;
    background: #ffffff;
    border-radius: var(--radius-xl);
    box-shadow: 0 40px 80px rgba(0, 0, 0, 0.3);
    overflow: hidden;
    animation: floatUpDown 6s ease-in-out infinite;
}

@keyframes floatUpDown {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-12px); }
}

.mockup-toolbar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: #f1f5f9;
    border-bottom: 1px solid #e2e8f0;
}

.mockup-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #cbd5e1;
}

.mockup-dot:nth-child(1) { background: #f87171; }
.mockup-dot:nth-child(2) { background: #fbbf24; }
.mockup-dot:nth-child(3) { background: #4ade80; }

.mockup-title {
    margin-left: 0.5rem;
    font-size: 11px;
    color: var(--color-text-tertiary);
}

.mockup-body {
    display: flex;
    height: 340px;
}

.mockup-sidebar {
    width: 140px;
    background: #f8fafc;
    border-right: 1px solid #e2e8f0;
    padding: 0.75rem 0.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.mockup-nav-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.625rem;
    border-radius: var(--radius-md);
    font-size: 12px;
    color: var(--color-text-tertiary);
    transition: all var(--transition-fast);
}

.mockup-nav-item svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

.mockup-nav-item.active {
    background: var(--gradient-brand);
    color: #ffffff;
}

.mockup-content {
    flex: 1;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.625rem;
}

.mockup-search {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: var(--radius-md);
    font-size: 12px;
    color: var(--color-text-tertiary);
    margin-bottom: 0.25rem;
}

.mockup-search svg {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
}

.mockup-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.625rem;
    border: 1px solid #f1f5f9;
    border-radius: var(--radius-sm);
    font-size: 11px;
    color: var(--color-text);
    animation: slideInRow 2s ease-in-out infinite;
    background: #ffffff;
}

@keyframes slideInRow {
    0%, 50% { opacity: 0.3; transform: translateY(4px); }
    100% { opacity: 1; transform: translateY(0); }
}

.mockup-tag {
    font-size: 10px;
    font-weight: 600;
    color: var(--color-primary);
    background: rgba(102, 126, 234, 0.1);
    padding: 2px 6px;
    border-radius: 4px;
    flex-shrink: 0;
}

.mockup-type {
    font-size: 10px;
    color: var(--color-text-tertiary);
    margin-left: auto;
    flex-shrink: 0;
}

/* ==========================================
   痛点区域
   ========================================== */
.pain-points {
    padding: var(--space-section) 0;
    background: var(--color-bg);
}

.pain-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.pain-card {
    text-align: center;
    padding: 2rem 1.25rem;
    background: #ffffff;
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-xl);
    transition: all var(--transition-base);
}

.pain-card:hover {
    border-color: #fecaca;
    box-shadow: var(--shadow-lg);
}

.pain-icon {
    display: flex;
    justify-content: center;
    margin-bottom: 1rem;
    transition: transform var(--transition-base);
}

.pain-card:hover .pain-icon {
    transform: scale(1.05);
}

.pain-icon svg {
    width: 48px;
    height: 48px;
    color: #ef4444;
}

.pain-card h3 {
    font-size: var(--text-base);
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: #dc2626;
}

.pain-card p {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.pain-arrow {
    display: flex;
    justify-content: center;
    margin-bottom: 1.5rem;
    animation: bounceDown 2s ease-in-out infinite;
}

.pain-arrow svg {
    width: 40px;
    height: 40px;
    color: var(--color-primary);
}

@keyframes bounceDown {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(8px); }
}

.pain-conclusion {
    text-align: center;
    font-size: var(--text-xl);
    font-weight: 600;
    color: var(--color-text);
}

.pain-conclusion strong {
    color: var(--color-primary);
}

/* ==========================================
   功能特性
   ========================================== */
.features {
    padding: var(--space-section) 0;
    background: var(--color-bg-alt);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.feature-card {
    background: #ffffff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: 2rem 1.75rem;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-brand);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.feature-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-xl);
    transform: translateY(-4px);
}

.feature-card:hover::before {
    opacity: 1;
}

.feature-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-lg);
    background: var(--gradient-brand-soft);
    margin-bottom: 1.25rem;
}

.feature-icon svg {
    width: 24px;
    height: 24px;
    color: var(--color-primary);
}

.feature-card h3 {
    font-size: var(--text-lg);
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.feature-card p {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.65;
}

/* ==========================================
   工作流程
   ========================================== */
.workflow {
    padding: var(--space-section) 0;
    background: var(--color-bg);
}

.workflow-steps {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 0;
    max-width: 1000px;
    margin: 0 auto;
}

.workflow-step {
    flex: 1;
    text-align: center;
    padding: 0 1rem;
}

.step-number {
    display: inline-block;
    font-size: var(--text-xs);
    font-weight: 700;
    letter-spacing: 0.05em;
    color: var(--color-primary);
    background: rgba(102, 126, 234, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
    margin-bottom: 1rem;
}

.step-icon {
    display: flex;
    justify-content: center;
    margin-bottom: 1.25rem;
}

.step-icon svg {
    width: 64px;
    height: 64px;
    color: var(--color-primary);
}

.workflow-step h3 {
    font-size: var(--text-xl);
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.workflow-step p {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.7;
}

.workflow-connector {
    display: flex;
    align-items: flex-start;
    padding-top: 2.5rem;
    flex-shrink: 0;
    color: var(--color-text-tertiary);
}

.workflow-connector svg {
    width: 24px;
    height: 24px;
}

/* ==========================================
   能力亮点
   ========================================== */
.highlights {
    padding: var(--space-section) 0;
    background: var(--color-bg-alt);
}

.highlights-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    max-width: 900px;
    margin: 0 auto;
}

.highlight-item {
    display: flex;
    gap: 1.25rem;
    align-items: flex-start;
}

.highlight-icon {
    flex-shrink: 0;
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-brand-soft);
    border-radius: var(--radius-xl);
}

.highlight-icon svg {
    width: 28px;
    height: 28px;
    color: var(--color-primary);
}

.highlight-text h3 {
    font-size: var(--text-lg);
    font-weight: 700;
    margin-bottom: 0.375rem;
}

.highlight-text p {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.65;
}

/* ==========================================
   适用人群
   ========================================== */
.audience {
    padding: var(--space-section) 0;
    background: var(--color-bg);
}

.audience-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.audience-card {
    background: #ffffff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: 2rem 1.75rem;
    text-align: center;
    transition: all var(--transition-base);
}

.audience-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.audience-card.featured {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.08);
}

.audience-icon {
    display: flex;
    justify-content: center;
    margin-bottom: 1.25rem;
}

.audience-icon svg {
    width: 64px;
    height: 64px;
    color: var(--color-primary);
}

.audience-card h3 {
    font-size: var(--text-xl);
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.audience-card > p {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.65;
    margin-bottom: 1.25rem;
}

.audience-card ul {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    text-align: left;
}

.audience-card ul li {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    padding-left: 1.25rem;
    position: relative;
}

.audience-card ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.55em;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--color-primary);
}

/* ==========================================
   版本对比
   ========================================== */
.pricing {
    padding: var(--space-section) 0;
    background: var(--color-bg-alt);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.pricing-card {
    background: #ffffff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-2xl);
    padding: 2.5rem 2rem;
    position: relative;
    transition: all var(--transition-base);
}

.pricing-card:hover {
    box-shadow: var(--shadow-lg);
}

.pricing-card.recommended {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1), var(--shadow-lg);
    transform: scale(1.03);
}

.pricing-card.recommended:hover {
    transform: scale(1.05);
}

.pricing-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    font-size: var(--text-xs);
    font-weight: 700;
    color: #ffffff;
    background: var(--gradient-brand);
    padding: 0.3rem 1.25rem;
    border-radius: 100px;
    white-space: nowrap;
}

.pricing-header {
    text-align: center;
    margin-bottom: 2rem;
}

.pricing-header h3 {
    font-size: var(--text-2xl);
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.pricing-desc {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-bottom: 1.25rem;
}

.pricing-price {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 0.125rem;
}

.price-symbol {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--color-text);
}

.price-num {
    font-size: 2.75rem;
    font-weight: 800;
    line-height: 1;
    letter-spacing: -0.02em;
}

.price-period {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.pricing-features {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.pricing-features li {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    font-size: var(--text-sm);
    color: var(--color-text);
}

.pricing-features li svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    color: var(--color-primary);
}

.pricing-btn {
    display: block;
    width: 100%;
    text-align: center;
    padding: 0.75rem;
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text);
    border: 1.5px solid var(--color-border);
    border-radius: 100px;
    transition: all var(--transition-fast);
}

.pricing-btn:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.pricing-btn.primary {
    color: #ffffff;
    background: var(--gradient-brand);
    border: none;
}

.pricing-btn.primary:hover {
    opacity: 0.9;
    box-shadow: var(--shadow-glow);
}

/* 终身档 */
.pricing-lifetime {
    max-width: 600px;
    margin: 0 auto;
}

.lifetime-card {
    position: relative;
    background: var(--gradient-brand);
    border-radius: var(--radius-2xl);
    padding: 2rem 2.5rem;
    color: #ffffff;
    overflow: hidden;
}

.lifetime-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    font-size: var(--text-xs);
    font-weight: 700;
    color: var(--color-primary);
    background: #ffffff;
    padding: 0.3rem 0.9rem;
    border-radius: 100px;
}

.lifetime-content {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.lifetime-content h3 {
    font-size: var(--text-xl);
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.lifetime-content p {
    font-size: var(--text-sm);
    opacity: 0.85;
    line-height: 1.5;
}

.lifetime-price {
    display: flex;
    align-items: baseline;
    gap: 0.125rem;
    margin-left: auto;
    flex-shrink: 0;
}

.lifetime-price .price-num {
    color: #ffffff;
}

.lifetime-price .price-symbol,
.lifetime-price .price-period {
    color: rgba(255, 255, 255, 0.75);
}

.lifetime-content .btn-primary {
    flex-shrink: 0;
}

/* ==========================================
   FAQ
   ========================================== */
.faq {
    padding: var(--space-section) 0;
    background: var(--color-bg);
}

.faq-list {
    max-width: 720px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.faq-item {
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: border-color var(--transition-fast);
}

.faq-item:hover {
    border-color: var(--color-border);
}

.faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 1.25rem 1.5rem;
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--color-text);
    text-align: left;
    transition: color var(--transition-fast);
}

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

.faq-question svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    transition: transform var(--transition-base);
    color: var(--color-text-tertiary);
}

.faq-question[aria-expanded="true"] svg {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-smooth), padding var(--transition-smooth);
}

.faq-answer p {
    padding: 0 1.5rem 1.25rem;
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: 1.7;
}

.faq-item.open .faq-answer {
    max-height: 200px;
}

/* ==========================================
   CTA
   ========================================== */
.cta {
    padding: var(--space-section) 0;
    background: var(--color-bg);
}

.cta-card {
    text-align: center;
    background: var(--gradient-brand);
    border-radius: var(--radius-3xl);
    padding: 4rem 2rem;
    color: #ffffff;
    position: relative;
    overflow: hidden;
}

.cta-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(255,255,255,0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 50%, rgba(255,255,255,0.06) 0%, transparent 50%);
}

.cta-card h2 {
    font-size: var(--text-4xl);
    font-weight: 800;
    margin-bottom: 1rem;
    position: relative;
}

.cta-card > p {
    font-size: var(--text-lg);
    opacity: 0.85;
    margin-bottom: 2.5rem;
    position: relative;
}

.cta-actions {
    position: relative;
}

.cta-note {
    margin-top: 1.25rem;
    font-size: var(--text-sm);
    opacity: 0.6;
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    padding: 4rem 0 2rem;
    background: var(--color-bg-dark);
    color: rgba(255, 255, 255, 0.7);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-brand p {
    font-size: var(--text-sm);
    line-height: 1.6;
    margin-top: 1rem;
    max-width: 280px;
}

.footer-brand .nav-logo {
    color: #ffffff;
}

.footer-links h4 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: #ffffff;
    margin-bottom: 1rem;
}

.footer-links a {
    display: block;
    font-size: var(--text-sm);
    margin-bottom: 0.625rem;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: #ffffff;
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    text-align: center;
    font-size: var(--text-xs);
    opacity: 0.5;
}

/* ==========================================
   响应式
   ========================================== */
@media (max-width: 1024px) {
    .pain-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .highlights-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
    }

    .workflow-steps {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }

    .workflow-step {
        max-width: 400px;
    }

    .workflow-connector {
        transform: rotate(90deg);
        padding-top: 0;
    }

    .audience-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin: 0 auto;
    }

    .pricing-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin-left: auto;
        margin-right: auto;
    }

    .pricing-card.recommended {
        transform: none;
    }

    .pricing-card.recommended:hover {
        transform: translateY(-4px);
    }

    .lifetime-content {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
    }

    .lifetime-price {
        margin-left: 0;
    }

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

@media (max-width: 768px) {
    :root {
        --space-section: 4rem;
    }

    .section-title {
        font-size: var(--text-3xl);
    }

    .nav-links {
        display: none;
    }

    .nav-cta {
        display: none;
    }

    .nav-toggle {
        display: flex;
    }

    /* 移动端菜单 */
    .nav.mobile-open .nav-links {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        padding: 1.5rem;
        gap: 1rem;
        border-bottom: 1px solid var(--color-border-light);
        box-shadow: var(--shadow-lg);
    }

    .nav.mobile-open .nav-links a {
        color: var(--color-text-secondary);
    }

    .nav.mobile-open .nav-links a:hover {
        color: var(--color-primary);
    }

    .hero {
        padding-top: 5rem;
        min-height: auto;
        padding-bottom: 3rem;
    }

    .hero-container {
        padding: 0;
        gap: 0;
    }

    .hero-inner {
        max-width: 100%;
    }

    .hero-stats {
        gap: 1.5rem;
    }

    .pain-grid {
        grid-template-columns: 1fr;
        max-width: 350px;
        margin-left: auto;
        margin-right: auto;
    }

    .features-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin-left: auto;
        margin-right: auto;
    }

    .cta-card h2 {
        font-size: var(--text-3xl);
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
    }

    .footer-brand {
        grid-column: 1 / -1;
    }
}

@media (max-width: 480px) {
    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }

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

    .hero-actions .btn-primary,
    .hero-actions .btn-secondary {
        justify-content: center;
    }

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

    .lifetime-card {
        padding: 1.5rem;
    }
}

/* --- 滚动动画 --- */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity var(--transition-smooth), transform var(--transition-smooth);
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- 移动端菜单动画 --- */
.nav-toggle.open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle.open span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

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

    html {
        scroll-behavior: auto;
    }
}