/* Slanted Gradient SaaS Style */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
    --saas-primary: #6366f1; /* Indigo */
    --saas-primary-hover: #4f46e5;
    --saas-secondary: #ec4899; /* Pink */
    --saas-bg: #f8fafc; /* Slate 50 */
    --saas-surface: #ffffff;
    --saas-text: #0f172a; /* Slate 900 */
    --saas-muted: #64748b; /* Slate 500 */
    --saas-border: #e2e8f0; /* Slate 200 */
    --font-main: 'Inter', sans-serif;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
}

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

body {
    background-color: var(--saas-bg);
    color: var(--saas-text);
    font-family: var(--font-main);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
    font-weight: 800;
    letter-spacing: -0.025em;
    line-height: 1.2;
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
    border-radius: var(--radius-lg);
}

/* Buttons */
.btn-saas {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: all 0.2s;
    cursor: pointer;
    border: 1px solid transparent;
}
.btn-saas.primary {
    background-color: var(--saas-primary);
    color: white;
    box-shadow: var(--shadow-md);
}
.btn-saas.primary:hover {
    background-color: var(--saas-primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}
.btn-saas.secondary {
    background-color: white;
    color: var(--saas-text);
    border-color: var(--saas-border);
    box-shadow: var(--shadow-sm);
}
.btn-saas.secondary:hover {
    background-color: #f1f5f9;
}
.btn-saas.white {
    background-color: white;
    color: var(--saas-primary);
    box-shadow: var(--shadow-md);
}
.btn-saas.white:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

/* 1. Navigation */
.saas-nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
    transition: all 0.3s ease;
    background: transparent;
}
.saas-nav.scrolled {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--saas-border);
    box-shadow: var(--shadow-sm);
}
.saas-nav.scrolled .nav-brand, .saas-nav.scrolled .nav-links a {
    color: var(--saas-text);
}
.nav-brand {
    font-size: 1.5rem;
    font-weight: 800;
    color: white;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.nav-brand svg { width: 24px; height: 24px; fill: currentColor; }
.nav-links {
    display: flex;
    gap: 2rem;
}
.nav-links a {
    font-weight: 500;
    color: rgba(255, 255, 255, 0.9);
}
.nav-links a:hover {
    opacity: 0.8;
}
.nav-actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}
.lang-switch {
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
}
.saas-nav.scrolled .lang-switch { color: var(--saas-text); }

/* 2. Hero Section (Slanted Gradient) */
.saas-hero {
    position: relative;
    padding: 12rem 2rem 10rem;
    background: linear-gradient(135deg, #4f46e5 0%, #ec4899 100%);
    color: white;
    text-align: center;
    z-index: 1;
}
/* The Slant */
.saas-hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100px;
    background: var(--saas-bg);
    clip-path: polygon(0 100%, 100% 0, 100% 100%);
    z-index: -1;
}
.hero-content {
    max-width: 800px;
    margin: 0 auto;
}
.hero-title {
    font-size: 4.5rem;
    margin-bottom: 1.5rem;
}
.hero-subtitle {
    font-size: 1.25rem;
    font-weight: 400;
    opacity: 0.9;
    margin-bottom: 2.5rem;
}
.hero-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
}
.trust-badges {
    display: flex;
    justify-content: center;
    gap: 2rem;
    font-size: 0.875rem;
    font-weight: 500;
    opacity: 0.8;
}
.trust-badges span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.trust-badges span::before {
    content: '✓';
    background: rgba(255,255,255,0.2);
    border-radius: 50%;
    width: 16px; height: 16px;
    display: flex; align-items: center; justify-content: center;
    font-size: 10px;
}

/* 3. Metrics (Floating Cards overlapping slant) */
.saas-metrics {
    max-width: 1200px;
    margin: -80px auto 4rem;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    position: relative;
    z-index: 10;
}
.metric-card {
    background: var(--saas-surface);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    text-align: center;
    border: 1px solid var(--saas-border);
}
.m-val {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--saas-primary);
    margin-bottom: 0.5rem;
}
.m-lbl {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--saas-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* 4. Features (Z-Pattern) */
.saas-features {
    max-width: 1200px;
    margin: 0 auto;
    padding: 6rem 2rem;
}
.feature-row {
    display: flex;
    align-items: center;
    gap: 4rem;
    margin-bottom: 8rem;
}
.feature-row:last-child { margin-bottom: 0; }
.feature-row:nth-child(even) { flex-direction: row-reverse; }
.feat-text { flex: 1; }
.feat-text h2 { font-size: 2.5rem; margin-bottom: 1rem; }
.feat-text p { font-size: 1.125rem; color: var(--saas-muted); margin-bottom: 2rem; }
.feat-list { list-style: none; }
.feat-list li { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 1rem; font-weight: 500; }
.feat-list li::before { content: ''; display: inline-block; width: 8px; height: 8px; background: var(--saas-primary); border-radius: 50%; }
.feat-visual { flex: 1; position: relative; }
.feat-visual::before {
    content: ''; position: absolute; top: -20px; left: -20px; right: 20px; bottom: 20px;
    background: linear-gradient(135deg, #e0e7ff 0%, #fae8ff 100%);
    border-radius: var(--radius-xl); z-index: -1;
}
.feature-row:nth-child(even) .feat-visual::before { left: 20px; right: -20px; }
.feat-visual img { box-shadow: var(--shadow-xl); border: 1px solid var(--saas-border); }

/* 5. Nodes (Slanted Dark Section) */
.saas-nodes {
    position: relative;
    padding: 10rem 2rem;
    background: #0f172a;
    color: white;
    text-align: center;
    z-index: 1;
}
.saas-nodes::before {
    content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 100px;
    background: var(--saas-bg); clip-path: polygon(0 0, 100% 0, 0 100%); z-index: -1;
}
.saas-nodes::after {
    content: ''; position: absolute; bottom: 0; left: 0; width: 100%; height: 100px;
    background: var(--saas-bg); clip-path: polygon(100% 100%, 100% 0, 0 100%); z-index: -1;
}
.saas-nodes h2 { font-size: 2.5rem; margin-bottom: 4rem; }
.node-grid {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1.5rem;
}
.node-card {
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    padding: 2rem;
    border-radius: var(--radius-lg);
    transition: all 0.2s;
}
.node-card:hover { background: rgba(255,255,255,0.1); transform: translateY(-5px); }
.node-card h4 { font-size: 1.25rem; margin-bottom: 0.5rem; }
.node-card span { color: #38bdf8; font-weight: 600; font-size: 0.875rem; }

/* 6. Reviews (Masonry-like Grid) */
.saas-reviews {
    max-width: 1200px;
    margin: 0 auto;
    padding: 8rem 2rem;
    text-align: center;
}
.saas-reviews h2 { font-size: 2.5rem; margin-bottom: 4rem; }
.review-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}
.review-card {
    background: var(--saas-surface);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--saas-border);
    text-align: left;
    display: flex;
    flex-direction: column;
}
.r-stars { color: #fbbf24; font-size: 1.25rem; margin-bottom: 1rem; }
.r-text { font-size: 1rem; color: var(--saas-muted); margin-bottom: 1.5rem; flex: 1; }
.r-user { font-weight: 700; display: flex; align-items: center; gap: 1rem; }
.r-avatar { width: 40px; height: 40px; border-radius: 50%; background: #e2e8f0; display: flex; align-items: center; justify-content: center; font-weight: 800; color: var(--saas-muted); }

/* 7. Pricing (3 Columns, Center Highlight) */
.saas-pricing {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem 8rem;
    text-align: center;
}
.saas-pricing h2 { font-size: 2.5rem; margin-bottom: 4rem; }
.price-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    align-items: center;
}
.price-card {
    background: var(--saas-surface);
    border-radius: var(--radius-xl);
    padding: 3rem 2rem;
    border: 1px solid var(--saas-border);
    box-shadow: var(--shadow-md);
    text-align: left;
}
.price-card.recommended {
    border: 2px solid var(--saas-primary);
    box-shadow: var(--shadow-xl);
    transform: scale(1.05);
    position: relative;
}
.price-card.recommended::before {
    content: '最受欢迎';
    position: absolute;
    top: -12px; left: 50%; transform: translateX(-50%);
    background: var(--saas-primary); color: white;
    padding: 4px 12px; border-radius: 20px; font-size: 0.75rem; font-weight: 700;
}
.p-name { font-size: 1.25rem; font-weight: 600; margin-bottom: 0.5rem; }
.p-desc { font-size: 0.875rem; color: var(--saas-muted); margin-bottom: 2rem; }
.p-price { font-size: 3rem; font-weight: 800; margin-bottom: 2rem; }
.p-price span { font-size: 1rem; color: var(--saas-muted); font-weight: 500; }
.p-features { list-style: none; margin-bottom: 2rem; }
.p-features li { padding: 0.75rem 0; border-bottom: 1px solid var(--saas-border); font-size: 0.875rem; color: var(--saas-muted); display: flex; align-items: center; gap: 0.5rem; }
.p-features li::before { content: '✓'; color: var(--saas-primary); font-weight: 800; }

/* 8. FAQ & Footer */
.saas-faq {
    max-width: 800px;
    margin: 0 auto;
    padding: 4rem 2rem 8rem;
}
.saas-faq h2 { font-size: 2.5rem; text-align: center; margin-bottom: 3rem; }
.faq-item {
    background: var(--saas-surface);
    border: 1px solid var(--saas-border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    margin-bottom: 1rem;
    box-shadow: var(--shadow-sm);
}
.faq-q { font-size: 1.125rem; font-weight: 600; margin-bottom: 0.5rem; }
.faq-a { color: var(--saas-muted); font-size: 0.95rem; }

.saas-footer {
    background: white;
    border-top: 1px solid var(--saas-border);
    padding: 4rem 2rem 2rem;
}
.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}
.footer-brand { font-size: 1.5rem; font-weight: 800; }
.footer-links { display: flex; gap: 2rem; }
.footer-links a { color: var(--saas-muted); font-weight: 500; font-size: 0.875rem; }
.footer-links a:hover { color: var(--saas-primary); }
.footer-copy { width: 100%; text-align: center; margin-top: 2rem; color: var(--saas-muted); font-size: 0.875rem; }

/* Subpages */
.sub-hero {
    padding: 10rem 2rem 6rem;
    background: linear-gradient(135deg, #4f46e5 0%, #ec4899 100%);
    color: white;
    text-align: center;
}
.sub-hero h1 { font-size: 3.5rem; margin-bottom: 1rem; }
.sub-hero p { font-size: 1.25rem; opacity: 0.9; }

.dl-grid {
    max-width: 1000px;
    margin: -3rem auto 8rem;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    position: relative;
    z-index: 10;
}
.dl-card {
    background: var(--saas-surface);
    border-radius: var(--radius-xl);
    padding: 3rem;
    text-align: center;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--saas-border);
}
.dl-icon { font-size: 3rem; margin-bottom: 1.5rem; }
.dl-card h3 { font-size: 1.5rem; margin-bottom: 0.5rem; }
.dl-card p { color: var(--saas-muted); margin-bottom: 2rem; }

.help-container {
    max-width: 1200px;
    margin: 4rem auto 8rem;
    padding: 0 2rem;
    display: grid;
    grid-template-columns: 250px 1fr;
    gap: 4rem;
}
.help-nav {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    position: sticky;
    top: 100px;
}
.help-nav a {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    color: var(--saas-muted);
    font-weight: 500;
}
.help-nav a:hover { background: #f1f5f9; color: var(--saas-text); }
.help-nav a.active { background: #e0e7ff; color: var(--saas-primary); font-weight: 600; }
.help-content {
    background: var(--saas-surface);
    padding: 3rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--saas-border);
}
.help-sec { margin-bottom: 3rem; }
.help-sec h2 { font-size: 1.8rem; margin-bottom: 1.5rem; color: var(--saas-text); border-bottom: 1px solid var(--saas-border); padding-bottom: 0.5rem; }
.help-sec h3 { font-size: 1.25rem; margin-bottom: 1rem; margin-top: 2rem; }
.help-sec p, .help-sec li { color: var(--saas-muted); margin-bottom: 1rem; }
.help-sec ul { padding-left: 1.5rem; }

/* Responsive */
@media (max-width: 1024px) {
    .saas-metrics { grid-template-columns: repeat(2, 1fr); }
    .feature-row, .feature-row:nth-child(even) { flex-direction: column; gap: 2rem; text-align: center; }
    .feat-list li { justify-content: center; }
    .price-grid { grid-template-columns: 1fr; max-width: 500px; margin: 0 auto; }
    .price-card.recommended { transform: none; }
    .dl-grid { grid-template-columns: 1fr; }
    .help-container { grid-template-columns: 1fr; }
    .help-nav { position: static; flex-direction: row; flex-wrap: wrap; }
}
@media (max-width: 768px) {
    .nav-links { display: none; }
    .hero-title { font-size: 3rem; }
    .hero-actions { flex-direction: column; }
    .review-grid { grid-template-columns: 1fr; }
    .footer-content { flex-direction: column; text-align: center; }
}