:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --primary-light: rgba(59, 130, 246, 0.15);
    --secondary-color: #0f172a;
    --accent-color: #f59e0b;
    --accent-hover: #d97706;
    --bg-color: #0f172a; /* Premium dark gradient background */
    --card-bg: #1e293b;
    --card-hover-bg: #283548;
    --text-color: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --radius: 12px;
    --radius-pill: 50px;
    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: var(--primary-color);
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.25;
    margin-bottom: 15px;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.4rem; }
.section-title { text-align: center; margin-bottom: 35px; }

.highlight {
    background: linear-gradient(135deg, #60a5fa 0%, #3b82f6 50%, #93c5fd 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 30px rgba(59, 130, 246, 0.4);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 1rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    gap: 8px;
}

.btn-primary {
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(59, 130, 246, 0.4);
}

.btn-primary:hover {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.6);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.05);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(8px);
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.btn-accent {
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(245, 158, 11, 0.4);
}
.btn-accent:hover {
    background: linear-gradient(135deg, #d97706 0%, #b45309 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(245, 158, 11, 0.6);
}

.btn-white {
    background-color: #ffffff;
    color: var(--bg-color);
    font-weight: 700;
}
.btn-white:hover {
    background-color: #f1f5f9;
    transform: translateY(-2px);
}

.btn-large {
    padding: 14px 32px;
    font-size: 1.1rem;
}

.btn-block {
    display: flex;
    width: 100%;
}

/* Navbar */
.navbar {
    background-color: rgba(15, 23, 42, 0.88);
    backdrop-filter: blur(16px);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.4rem;
    font-weight: 700;
    color: #fff;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-links {
    display: flex;
    gap: 25px;
}
.nav-links a {
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
}
.nav-links a:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    padding: 90px 0 70px;
    background: radial-gradient(circle at 80% 20%, rgba(59, 130, 246, 0.12) 0%, transparent 50%),
                radial-gradient(circle at 20% 80%, rgba(15, 23, 42, 1) 0%, #0f172a 100%);
    overflow: hidden;
    position: relative;
}

.hero-container {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 40px;
    align-items: center;
}

.hero-content {
    text-align: left;
}

.hero-content p {
    font-size: 1.15rem;
    color: var(--text-muted);
    margin-bottom: 25px;
}

.hero-actions {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

/* Hero Pills (场景痛点 + 零风险信任标签) */
.hero-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 25px;
}

.pill-item {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(30, 41, 59, 0.8);
    border: 1px solid rgba(59, 130, 246, 0.3);
    border-radius: var(--radius-pill);
    font-size: 0.9rem;
    font-weight: 600;
    color: #e2e8f0;
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    transition: var(--transition);
}

.pill-item:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    background: rgba(59, 130, 246, 0.15);
}

.trust-micro-text {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 10px;
    display: flex;
    align-items: center;
    gap: 6px;
}

/* Hero Visual */
.hero-visual {
    position: relative;
    height: 380px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.dynamic-card {
    position: absolute;
    background: rgba(30, 41, 59, 0.75);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: var(--radius);
    padding: 18px 26px;
    display: flex;
    align-items: center;
    gap: 15px;
    box-shadow: var(--shadow-lg);
    animation: float 6s ease-in-out infinite;
}

.dynamic-card .icon {
    font-size: 1.8rem;
}
.dynamic-card .text {
    font-weight: 600;
    color: #fff;
    font-size: 0.95rem;
}

.card-1 {
    top: 10%;
    left: 5%;
    animation-delay: 0s;
}
.card-2 {
    top: 45%;
    right: 5%;
    animation-delay: 2s;
}
.card-3 {
    bottom: 10%;
    left: 15%;
    animation-delay: 4s;
}

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

/* Section styling */
section {
    padding: 75px 0;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 30px;
    transition: var(--transition);
}

.card:hover {
    border-color: rgba(59, 130, 246, 0.5);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
}

.feature-card { text-align: center; }
.feature-card .icon {
    font-size: 2.8rem;
    margin-bottom: 15px;
}
.feature-card p, .support-card p {
    color: var(--text-muted);
}

/* Pricing Header Promos */
.pricing-header-box {
    margin-bottom: 35px;
    text-align: center;
}

.promo-banner {
    display: inline-block;
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.2) 0%, rgba(217, 119, 6, 0.3) 100%);
    border: 1px solid rgba(245, 158, 11, 0.6);
    border-radius: 30px;
    padding: 10px 24px;
    font-weight: 700;
    color: #fef08a;
    font-size: 1rem;
    box-shadow: 0 4px 15px rgba(245, 158, 11, 0.2);
    margin-bottom: 15px;
}

.countdown-bar {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-size: 0.95rem;
    color: #93c5fd;
    margin-top: 10px;
}

.timer-box {
    background: #1e293b;
    border: 1px solid #3b82f6;
    padding: 2px 8px;
    border-radius: 6px;
    font-family: monospace;
    font-weight: 700;
    color: #ffffff;
    font-size: 1.05rem;
}

/* Pricing Grid */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    align-items: stretch;
}

.pricing-card {
    position: relative;
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.pricing-card.featured {
    border: 2px solid var(--primary-color);
    background: linear-gradient(180deg, #1e293b 0%, #0f172a 100%);
    box-shadow: 0 10px 35px rgba(59, 130, 246, 0.25);
    transform: scale(1.03);
}

.badge {
    position: absolute;
    top: -14px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    color: #fff;
    padding: 4px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 700;
    box-shadow: 0 4px 10px rgba(239, 68, 68, 0.4);
    white-space: nowrap;
}

.price {
    font-size: 2.6rem;
    font-weight: 800;
    margin: 15px 0 10px;
    color: #fff;
}

.price span {
    font-size: 1rem;
    color: var(--text-muted);
    font-weight: 400;
}

.plan-features {
    text-align: left;
    margin-bottom: 25px;
    flex-grow: 1;
}

.plan-features li {
    margin-bottom: 12px;
    color: var(--text-muted);
    position: relative;
    padding-left: 24px;
    font-size: 0.95rem;
}

.plan-features li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #10b981;
    font-weight: bold;
}

.guarantee-badge {
    margin-top: 10px;
    font-size: 0.8rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
}

/* Articles Grid */
.articles-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.article-card {
    display: flex;
    flex-direction: column;
    text-align: left;
    text-decoration: none;
    color: var(--text-color);
}

.article-img {
    height: 140px;
    background: linear-gradient(135deg, #1e293b, #0f172a);
    border-radius: var(--radius) var(--radius) 0 0;
    margin: -30px -30px 20px -30px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 2.8rem;
    font-weight: bold;
    color: rgba(255, 255, 255, 0.08);
}

.article-card h3 {
    font-size: 1.1rem;
    margin-bottom: 10px;
    color: #fff;
    line-height: 1.4;
}

.article-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

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

.faq-item {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 15px;
}

.faq-item h3 {
    font-size: 1.15rem;
    margin-bottom: 8px;
    color: #fff;
}

.faq-item p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Footer */
.footer {
    background-color: #0b1120;
    padding: 50px 0 90px; /* Space for sticky bar on mobile */
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 25px;
    margin-bottom: 20px;
}

.footer-links a {
    color: var(--text-muted);
    font-weight: 500;
}

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

.copyright {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* 挽留弹窗 (Exit-Intent Popup Modal) */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(8px);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    padding: 20px;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-card {
    background: linear-gradient(145deg, #1e293b 0%, #0f172a 100%);
    border: 2px solid var(--primary-color);
    border-radius: 16px;
    width: 100%;
    max-width: 480px;
    padding: 35px 25px 25px;
    position: relative;
    text-align: center;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.7);
    transform: translateY(20px);
    transition: all 0.3s ease;
}

.modal-overlay.active .modal-card {
    transform: translateY(0);
}

.modal-close {
    position: absolute;
    top: 12px;
    right: 15px;
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    line-height: 1;
}

.modal-close:hover {
    color: #fff;
}

.modal-card h3 {
    font-size: 1.5rem;
    color: #fff;
    margin-bottom: 10px;
}

.modal-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 20px;
}

.modal-coupon-box {
    background: rgba(59, 130, 246, 0.1);
    border: 1px dashed var(--primary-color);
    border-radius: var(--radius);
    padding: 15px;
    margin-bottom: 20px;
}

.coupon-code {
    font-size: 1.6rem;
    font-weight: 800;
    color: #60a5fa;
    letter-spacing: 2px;
    margin: 5px 0;
}

/* 移动端悬浮购买条 (Mobile Sticky Bar) */
.mobile-sticky-bar {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background: rgba(15, 23, 42, 0.92);
    backdrop-filter: blur(16px);
    border-top: 1px solid var(--border-color);
    padding: 10px 15px calc(10px + env(safe-area-inset-bottom));
    z-index: 90;
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.4);
}

.sticky-bar-content {
    display: flex;
    gap: 10px;
    max-width: 500px;
    margin: 0 auto;
}

.sticky-bar-content .btn {
    flex: 1;
    padding: 10px 14px;
    font-size: 0.92rem;
}

/* Responsive Media Queries */
@media (max-width: 992px) {
    .feature-grid, .pricing-grid, .articles-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .pricing-card.featured {
        transform: scale(1);
    }
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .hero-content {
        text-align: center;
    }
    .hero-actions {
        justify-content: center;
    }
    .hero-pills {
        justify-content: center;
    }
    .trust-micro-text {
        justify-content: center;
    }
    .hero-visual {
        height: 320px;
    }
    .nav-links {
        display: none;
    }
}

@media (max-width: 768px) {
    .mobile-sticky-bar {
        display: block;
    }
    .feature-grid, .pricing-grid, .grid-2, .articles-grid {
        grid-template-columns: 1fr;
    }
    .hero {
        padding: 50px 0 40px;
    }
    h1 { font-size: 1.9rem; }
    h2 { font-size: 1.6rem; }
    .nav-actions .btn-secondary {
        display: none;
    }
}

@media (max-width: 480px) {
    .btn {
        padding: 10px 18px;
        font-size: 0.95rem;
    }
    .hero-actions {
        flex-direction: column;
    }
    .hero-actions .btn {
        width: 100%;
    }
}