/* ===== style.css ===== */
/* ===== 全局重置 & 基础 ===== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #4A9AD9;
    --primary-light: #7BB8E8;
    --primary-lighter: #B8D8F8;
    --primary-lightest: #E8F4FD;
    --primary-dark: #2D7FC4;
    --primary-deep: #1A5F96;
    --bg-body: #F5F9FF;
    --bg-white: #FFFFFF;
    --text-dark: #1A2A3A;
    --text-muted: #4A5A6A;
    --text-light: #7A8A9A;
    --shadow-sm: 0 4px 20px rgba(74, 154, 217, 0.10);
    --shadow-md: 0 8px 40px rgba(74, 154, 217, 0.15);
    --shadow-lg: 0 16px 60px rgba(74, 154, 217, 0.20);
    --radius: 16px;
    --radius-sm: 10px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font);
    background: var(--bg-body);
    color: var(--text-dark);
    line-height: 1.6;
}

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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.section-title {
    font-size: 2.2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
    color: var(--text-dark);
}

.section-sub {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-muted);
    max-width: 640px;
    margin: 0 auto 48px;
}

.section-title .highlight {
    color: var(--primary);
}

/* ===== 按钮 ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 36px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    background: var(--bg-white);
    color: var(--text-dark);
    box-shadow: var(--shadow-sm);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff;
    box-shadow: 0 4px 24px rgba(74, 154, 217, 0.35);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 32px rgba(74, 154, 217, 0.45);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: #fff;
}

.btn-sm {
    padding: 10px 24px;
    font-size: 0.9rem;
}

/* ===== 导航 ===== */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 16px 0;
    transition: var(--transition);
    background: rgba(255, 255, 255, 0.70);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(74, 154, 217, 0.08);
}

header.scrolled {
    background: rgba(255, 255, 255, 0.92);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.06);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.3rem;
    color: var(--primary-dark);
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 1.2rem;
    font-weight: 800;
}

.logo span {
    color: var(--text-dark);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    font-size: 0.95rem;
    color: var(--text-muted);
    transition: var(--transition);
    font-weight: 500;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}

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

.nav-links a:hover::after {
    width: 100%;
}

.nav-cta {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff !important;
    padding: 8px 20px;
    border-radius: 50px;
    font-weight: 600;
}

.nav-cta::after {
    display: none !important;
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(74, 154, 217, 0.35);
    color: #fff !important;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 4px;
    background: none;
    border: none;
}

.hamburger span {
    display: block;
    width: 26px;
    height: 2.5px;
    background: var(--text-dark);
    border-radius: 4px;
    transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ===== Hero ===== */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(170deg, var(--primary-lightest) 0%, #f0f8ff 60%, var(--bg-body) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -40%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(74, 154, 217, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(74, 154, 217, 0.06) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-content h1 {
    font-size: 3.2rem;
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -0.03em;
    margin-bottom: 20px;
    color: var(--text-dark);
}

.hero-content h1 .highlight {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-content p {
    font-size: 1.2rem;
    color: var(--text-muted);
    max-width: 480px;
    margin-bottom: 32px;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

.hero-stats {
    display: flex;
    gap: 48px;
    margin-top: 48px;
    padding-top: 32px;
    border-top: 1px solid rgba(74, 154, 217, 0.15);
}

.hero-stats-item {
    text-align: center;
}

.hero-stats-item .number {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-dark);
    display: block;
}

.hero-stats-item .label {
    font-size: 0.85rem;
    color: var(--text-light);
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-illustration {
    width: 100%;
    max-width: 480px;
    background: linear-gradient(145deg, var(--bg-white), var(--primary-lightest));
    border-radius: var(--radius);
    padding: 40px 32px;
    box-shadow: var(--shadow-lg);
    border: 1px solid rgba(74, 154, 217, 0.10);
    text-align: center;
}

.hero-illustration .emoji-big {
    font-size: 4rem;
    margin-bottom: 16px;
}

.hero-illustration h3 {
    font-size: 1.3rem;
    color: var(--text-dark);
    margin-bottom: 8px;
}

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

.hero-illustration .badge-row {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.hero-illustration .badge {
    background: var(--primary-lightest);
    padding: 6px 18px;
    border-radius: 50px;
    font-size: 0.8rem;
    color: var(--primary-dark);
    font-weight: 600;
}

/* ===== 功能 ===== */
.features {
    padding: 80px 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.feature-card {
    background: var(--bg-white);
    padding: 32px 28px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid rgba(74, 154, 217, 0.06);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-light), var(--primary));
    opacity: 0;
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-md);
    border-color: rgba(74, 154, 217, 0.12);
}

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

.feature-icon {
    font-size: 2.2rem;
    margin-bottom: 16px;
    display: block;
}

.feature-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-dark);
}

.feature-card p {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* ===== 价格 ===== */
.pricing {
    padding: 80px 0;
    background: var(--bg-white);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    margin-top: 16px;
}

.pricing-card {
    background: var(--bg-body);
    border-radius: var(--radius);
    padding: 36px 28px 32px;
    border: 1px solid rgba(74, 154, 217, 0.08);
    transition: var(--transition);
    text-align: center;
    position: relative;
}

.pricing-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.pricing-card.popular {
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
    background: var(--bg-white);
}

.pricing-card.popular .popular-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff;
    font-size: 0.7rem;
    font-weight: 700;
    padding: 4px 16px;
    border-radius: 50px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 12px;
}

.popular-badge {
    display: none;
}

.pricing-card .plan-name {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 4px;
}

.pricing-card .plan-price {
    font-size: 2.6rem;
    font-weight: 800;
    color: var(--primary-dark);
    margin: 12px 0 4px;
}

.pricing-card .plan-price small {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-light);
}

.pricing-card .plan-desc {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 20px;
}

.pricing-card .plan-features {
    list-style: none;
    text-align: left;
    margin: 20px 0 28px;
    padding: 0;
}

.pricing-card .plan-features li {
    padding: 6px 0;
    font-size: 0.92rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 10px;
}

.pricing-card .plan-features li::before {
    content: '✓';
    color: var(--primary);
    font-weight: 700;
    font-size: 1.1rem;
}

.pricing-card .btn {
    width: 100%;
    justify-content: center;
}

/* ===== 版本对比 ===== */
.compare {
    padding: 80px 0;
    background: var(--bg-body);
}

.table-wrap {
    overflow-x: auto;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    background: var(--bg-white);
    border: 1px solid rgba(74, 154, 217, 0.06);
}

.compare-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
    min-width: 600px;
}

.compare-table th,
.compare-table td {
    padding: 16px 24px;
    text-align: center;
    border-bottom: 1px solid rgba(74, 154, 217, 0.06);
}

.compare-table th {
    background: var(--primary-lightest);
    font-weight: 700;
    color: var(--primary-dark);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.compare-table th:first-child,
.compare-table td:first-child {
    text-align: left;
    font-weight: 600;
    color: var(--text-dark);
}

.compare-table tr:last-child td {
    border-bottom: none;
}

.compare-table td .check {
    color: var(--primary);
    font-weight: 700;
}

.compare-table td .cross {
    color: #ccc;
}

.compare-table tr:hover td {
    background: rgba(74, 154, 217, 0.02);
}

/* ===== FAQ ===== */
.faq {
    padding: 80px 0;
    background: var(--bg-white);
}

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

.faq-item {
    border-bottom: 1px solid rgba(74, 154, 217, 0.08);
    padding: 8px 0;
}

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

.faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 0;
    cursor: pointer;
    font-weight: 600;
    font-size: 1.05rem;
    color: var(--text-dark);
    transition: var(--transition);
    gap: 16px;
}

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

.faq-question .toggle-icon {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--primary-lightest);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: var(--primary);
    transition: var(--transition);
    font-weight: 300;
}

.faq-item.active .faq-question .toggle-icon {
    transform: rotate(45deg);
    background: var(--primary);
    color: #fff;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.3s ease;
    padding: 0 0 0 0;
    color: var(--text-muted);
    font-size: 0.98rem;
    line-height: 1.7;
}

.faq-item.active .faq-answer {
    max-height: 300px;
    padding: 0 0 20px 0;
}

/* ===== CTA ===== */
.cta-section {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--primary-lightest), var(--bg-body));
    text-align: center;
}

.cta-section h2 {
    font-size: 2.4rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.cta-section p {
    font-size: 1.1rem;
    color: var(--text-muted);
    max-width: 520px;
    margin: 0 auto 32px;
}

.cta-section .btn-group {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

/* ===== 页脚 ===== */
footer {
    padding: 40px 0;
    background: var(--text-dark);
    color: rgba(255, 255, 255, 0.7);
    text-align: center;
    font-size: 0.9rem;
}

footer .footer-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

footer .footer-links {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
    justify-content: center;
}

footer .footer-links a {
    color: rgba(255, 255, 255, 0.6);
    transition: var(--transition);
    font-size: 0.85rem;
}

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

footer .copy {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.4);
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .pricing-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .hero-content p {
        margin-left: auto;
        margin-right: auto;
    }
    .hero-actions {
        justify-content: center;
    }
    .hero-stats {
        justify-content: center;
    }
    .hero-illustration {
        max-width: 400px;
        margin: 0 auto;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        background: var(--bg-white);
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        padding: 24px;
        gap: 16px;
        box-shadow: var(--shadow-md);
        border-radius: 0 0 var(--radius) var(--radius);
        border: 1px solid rgba(74, 154, 217, 0.06);
        border-top: none;
    }

    .nav-links.open {
        display: flex;
    }

    .hamburger {
        display: flex;
    }

    .hero {
        padding: 120px 0 60px;
    }
    .hero-content h1 {
        font-size: 2.2rem;
    }
    .hero-content p {
        font-size: 1rem;
    }
    .hero-stats {
        gap: 24px;
        flex-wrap: wrap;
    }
    .hero-stats-item .number {
        font-size: 1.4rem;
    }

    .section-title {
        font-size: 1.7rem;
    }
    .section-sub {
        font-size: 1rem;
    }

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

    .compare-table th,
    .compare-table td {
        padding: 12px 16px;
        font-size: 0.85rem;
    }

    .cta-section h2 {
        font-size: 1.8rem;
    }

    header {
        padding: 12px 0;
    }
    .logo {
        font-size: 1.1rem;
    }
    .logo-icon {
        width: 34px;
        height: 34px;
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    .hero-content h1 {
        font-size: 1.8rem;
    }
    .hero-illustration {
        padding: 24px 16px;
    }
    .hero-illustration .emoji-big {
        font-size: 3rem;
    }
    .pricing-card .plan-price {
        font-size: 2rem;
    }
    .btn {
        padding: 12px 24px;
        font-size: 0.9rem;
    }
}