/* style.css - “轻语”品牌风格：通透、互动、现代 */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Noto+Sans+SC:wght@400;500;700;900&display=swap');

:root {
    --primary-color: #6366f1; /* Soft Indigo */
    --primary-hover: #4f46e5;
    --primary-gradient: linear-gradient(135deg, #818cf8 0%, #c084fc 100%);
    --primary-gradient-hover: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
    --text-main: #1e293b;
    --text-light: #64748b;
    --bg-main: #ffffff;
    --bg-light: #f8fafc; /* Very light cool gray */
    --bg-glass: rgba(255, 255, 255, 0.75);
    --border-color: #e2e8f0;
    --white: #ffffff;
    --shadow-soft: 0 10px 40px -10px rgba(99, 102, 241, 0.1);
    --shadow-hover: 0 20px 40px -10px rgba(99, 102, 241, 0.25);
    --radius-lg: 24px;
    --radius-md: 16px;
}

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

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
}

html::before {
    content: '';
    position: fixed;
    width: 40vw;
    height: 40vw;
    background: #38bdf8; /* Light Blue */
    top: 30%;
    left: 30%;
    border-radius: 50%;
    filter: blur(120px);
    z-index: -1;
    opacity: 0.4;
    animation: floatBg 25s infinite alternate-reverse ease-in-out;
}

body {
    font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.7;
    color: var(--text-main);
    background-color: var(--bg-light);
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

body::before, body::after {
    content: '';
    position: fixed;
    border-radius: 50%;
    filter: blur(120px);
    z-index: -1;
    opacity: 0.5;
    animation: floatBg 20s infinite alternate ease-in-out;
}

body::before {
    width: 45vw;
    height: 45vw;
    background: #c084fc; /* Purple */
    top: -10%;
    left: -10%;
}

body::after {
    width: 45vw;
    height: 45vw;
    background: #818cf8; /* Indigo */
    bottom: -10%;
    right: -10%;
    animation-delay: -10s;
}

@keyframes floatBg {
    0% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(10vw, 5vh) scale(1.1); }
    66% { transform: translate(-5vw, 15vh) scale(0.9); }
    100% { transform: translate(5vw, -5vh) scale(1); }
}

/* Header & Nav */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px max(5%, calc(50% - 550px));
    background: var(--bg-glass);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255,255,255,0.5);
    box-shadow: 0 4px 20px rgba(0,0,0,0.03);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: all 0.3s ease;
}

.logo {
    font-size: 26px;
    font-weight: 900;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 1px;
}

nav a {
    margin: 0 18px;
    text-decoration: none;
    color: var(--text-light);
    font-weight: 500;
    position: relative;
    transition: color 0.3s ease;
}

nav a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -6px;
    left: 50%;
    background: var(--primary-gradient);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    transform: translateX(-50%);
    border-radius: 2px;
}

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

nav a:hover::after {
    width: 100%;
}

/* Buttons */
.cta-btn {
    display: inline-block;
    background: var(--primary-gradient);
    color: var(--white);
    padding: 14px 32px;
    text-decoration: none;
    border-radius: 30px; /* Pill shape */
    font-weight: 600;
    border: none;
    cursor: pointer;
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.3);
    transform: translateY(0);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-align: center;
}

.cta-btn:hover {
    background: var(--primary-gradient-hover);
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 10px 25px rgba(99, 102, 241, 0.45);
    color: var(--white);
}

.cta-btn.btn-small {
    padding: 10px 24px;
    font-size: 14px;
}

.cta-btn.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid #cbd5e1;
    box-shadow: none;
}

.cta-btn.btn-outline:hover {
    background: rgba(99, 102, 241, 0.05);
    border-color: var(--primary-hover);
    color: var(--primary-hover);
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.15);
}

/* Sections */
section {
    padding: 100px 5%;
}

.bg-light {
    background-color: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

.section-title {
    text-align: center;
    font-size: 36px;
    margin-bottom: 60px;
    font-weight: 800;
    color: var(--text-main);
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 140px 5% 160px;
    background: transparent;
    position: relative;
}

.hero h1 {
    font-size: 52px;
    margin-bottom: 24px;
    font-weight: 900;
    line-height: 1.25;
    background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -1px;
}

.hero .hero-subtitle {
    font-size: 22px;
    font-weight: 600;
    color: #334155;
    margin-bottom: 20px;
}

.hero p {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 45px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* Grid Layouts */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 35px;
    max-width: 1200px;
    margin: 0 auto;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 35px;
    max-width: 1100px;
    margin: 0 auto;
}

/* Cards (Soft UI & Glassmorphism hints) */
.card {
    background: var(--white);
    padding: 45px 35px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(255, 255, 255, 0.6);
    text-align: center;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275); /* Bouncy effect */
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
    border-color: rgba(99, 102, 241, 0.15);
}

.card .icon {
    font-size: 48px;
    margin-bottom: 25px;
    display: inline-block;
    transition: transform 0.4s ease;
}

.card:hover .icon {
    transform: scale(1.15) rotate(5deg);
}

.card h3 {
    margin-bottom: 15px;
    font-size: 22px;
    font-weight: 700;
}

/* Pricing */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 35px;
    max-width: 1150px;
    margin: 0 auto;
}

.price-card {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 45px 35px;
    text-align: center;
    background: var(--white);
    position: relative;
    box-shadow: var(--shadow-soft);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.price-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
    border-color: rgba(99, 102, 241, 0.3);
}

.price-card.popular {
    border: 2px solid #818cf8;
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.badge {
    position: absolute;
    top: -16px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-gradient);
    color: var(--white);
    padding: 6px 18px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 700;
    box-shadow: 0 4px 12px rgba(168, 85, 247, 0.35);
    letter-spacing: 1px;
}

.price-card h3 {
    font-size: 20px;
    color: var(--text-light);
    font-weight: 600;
}

.price {
    font-size: 48px;
    font-weight: 900;
    margin: 25px 0;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.price span {
    font-size: 16px;
    color: var(--text-light);
    font-weight: 500;
    -webkit-text-fill-color: var(--text-light);
}

.features-list {
    list-style: none;
    margin: 35px 0;
    text-align: left;
}

.features-list li {
    margin-bottom: 16px;
    padding-left: 32px;
    position: relative;
    color: var(--text-main);
    font-weight: 500;
}

.features-list li::before {
    content: '✦'; /* Changed from tick to a sparkle/star for ethereal look */
    color: #a855f7;
    font-size: 18px;
    position: absolute;
    left: 0;
    top: -2px;
}

.price-card .cta-btn {
    width: 100%;
}

/* Reviews */
.reviews-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 35px;
    max-width: 1150px;
    margin: 0 auto;
}
.review-card {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 35px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(255, 255, 255, 0.6);
    text-align: left;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.review-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
    border-color: rgba(99, 102, 241, 0.15);
}
.review-card p {
    font-size: 16px;
    color: var(--text-light);
    margin-bottom: 25px;
    font-style: italic;
    line-height: 1.8;
}
.reviewer {
    color: var(--primary-color);
    font-weight: 700;
    font-size: 15px;
}

/* FAQ */
.faq-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

.faq-item {
    background: var(--white);
    padding: 30px;
    border-radius: var(--radius-md);
    box-shadow: 0 4px 20px rgba(0,0,0,0.02);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.faq-item:hover {
    border-color: #cbd5e1;
    box-shadow: 0 8px 30px rgba(0,0,0,0.04);
}

.faq-item h4 {
    margin-bottom: 12px;
    font-size: 18px;
    color: var(--text-main);
    font-weight: 700;
}

.faq-item p {
    color: var(--text-light);
    font-size: 15px;
    line-height: 1.8;
}

/* Subpages Container */
.page-container {
    max-width: 800px;
    margin: 60px auto;
    padding: 50px;
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
}

.page-container.page-card {
    max-width: 480px;
    background: var(--bg-glass);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.7);
    padding: 40px 35px;
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.1);
}

.sitemap-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 15px;
    margin-bottom: 40px;
}
.sitemap-card {
    background: rgba(255, 255, 255, 0.5);
    border: 1px solid rgba(99, 102, 241, 0.2);
    padding: 15px;
    border-radius: var(--radius-md);
    text-align: center;
    color: var(--text-main) !important;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s ease;
    text-decoration: none !important;
    display: flex;
    align-items: center;
    justify-content: center;
}
.sitemap-card:hover {
    background: var(--white);
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
    color: var(--primary-color) !important;
    border-color: rgba(99, 102, 241, 0.5);
}
.page-container h1 {
    margin-bottom: 35px;
    text-align: center;
    font-weight: 800;
    font-size: 32px;
}
.page-container h2 {
    margin: 35px 0 15px;
    font-size: 22px;
    color: var(--primary-color);
}
.page-container p {
    margin-bottom: 15px;
    color: var(--text-light);
    line-height: 1.8;
}
.page-container ul {
    margin-left: 20px;
    margin-bottom: 20px;
    color: var(--text-light);
}
.page-container li {
    margin-bottom: 10px;
}
.page-container a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}
.page-container a:hover {
    text-decoration: underline;
}

/* Footer */
footer {
    background: #0f172a;
    color: #94a3b8;
    padding: 60px 5% 40px;
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 35px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.footer-links a {
    color: #cbd5e1;
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: #a855f7;
}

/* Media Queries (Responsive) */
@media (max-width: 900px) {
    .grid-3, .pricing-grid, .reviews-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .grid-3, .grid-2, .pricing-grid, .faq-grid, .reviews-grid {
        grid-template-columns: 1fr;
    }
    
    .hero {
        padding: 80px 5% 100px;
    }
    
    .hero h1 {
        font-size: 36px;
    }
    
    header {
        flex-direction: column;
        gap: 15px;
        padding: 20px;
    }
    
    nav {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: 12px;
    }
    
    nav a {
        margin: 0 5px;
        font-size: 14px;
    }
    
    .cta-btn {
        padding: 16px 24px;
        font-size: 16px;
        width: 100%;
    }
    
    header .cta-btn {
        margin-top: 10px;
    }
    
    .page-container {
        margin: 30px 5%;
        padding: 30px 20px;
    }
}

/* Accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: 8px 15px;
    z-index: 1000;
    transition: top 0.3s;
    text-decoration: none;
    font-weight: bold;
}
.skip-link:focus {
    top: 0;
}

/* FAQ Details Semantic */
details.faq-item {
    cursor: pointer;
}
details.faq-item summary {
    list-style: none;
    outline: none;
}
details.faq-item summary::-webkit-details-marker {
    display: none;
}
details.faq-item h4 {
    display: inline-block;
    margin-bottom: 0;
}
details.faq-item[open] h4 {
    margin-bottom: 12px;
}