/* Reset & Base */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { 
    font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif; 
    /* Watercolor Paper Texture Background */
    background-color: #fdfcf8; 
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='paperTexture'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.04' numOctaves='5' result='noise'/%3E%3CfeColorMatrix type='matrix' values='1 0 0 0 0 0 0.98 0 0 0 0 0 0.96 0 0 0 0 0 0.1 0' in='noise' result='coloredNoise'/%3E%3CfeBlend in='SourceGraphic' in2='coloredNoise' mode='multiply'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' fill='%23fdfcf8' filter='url(%23paperTexture)'/%3E%3C/svg%3E");
    color: #4a5568; 
    line-height: 1.7; 
    min-height: 100vh; 
    overflow-x: hidden; 
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* Theme Variables - Watercolor */
:root {
    --wc-blue-light: rgba(167, 207, 235, 0.4);
    --wc-blue-mid: rgba(116, 172, 223, 0.6);
    --wc-blue-dark: #4a90e2;
    --wc-text-main: #2d3748;
    --wc-text-muted: #718096;
    --wc-bg-white: rgba(255, 255, 255, 0.85);
}

/* Navigation */
.navbar { 
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
    padding: 20px 5%; 
    background: transparent;
    position: sticky; 
    top: 0; 
    z-index: 100; 
    transition: all 0.3s;
}
.navbar.scrolled {
    background: rgba(253, 252, 248, 0.95);
    box-shadow: 0 4px 20px rgba(116, 172, 223, 0.1);
    backdrop-filter: blur(2px);
}
.nav-logo { 
    font-size: 24px; 
    font-weight: 300; 
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--wc-blue-dark);
    letter-spacing: 2px;
}
.nav-logo svg {
    width: 32px;
    height: 32px;
    fill: var(--wc-blue-dark);
    opacity: 0.8;
}
.nav-links { display: flex; gap: 35px; align-items: center; font-weight: 400; }
.nav-links a { 
    color: var(--wc-text-muted); 
    transition: all 0.4s ease; 
    font-size: 15px; 
    position: relative;
    padding: 5px 0;
}
.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0; left: 50%; width: 0; height: 6px;
    background: var(--wc-blue-light);
    transition: all 0.4s ease;
    transform: translateX(-50%);
    border-radius: 10px;
    z-index: -1;
}
.nav-links a:hover { color: var(--wc-blue-dark); }
.nav-links a:hover::after { width: 110%; }

.btn-download-nav { 
    padding: 8px 24px !important; 
    background: var(--wc-blue-dark);
    color: #fff !important; 
    border-radius: 30px;
    transition: all 0.4s ease; 
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.3);
}
.btn-download-nav::after { display: none; }
.btn-download-nav:hover { 
    background: #3182ce;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.4);
}

/* Hero Section - Watercolor */
.hero-wrapper {
    position: relative;
    min-height: 90vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 80px 5% 100px;
    overflow: hidden;
}

/* Watercolor Wash Backgrounds */
.watercolor-wash {
    position: absolute;
    border-radius: 50%;
    filter: blur(2px);
    z-index: 0;
    opacity: 0.7;
    animation: floatWash 20s infinite alternate ease-in-out;
}
.wash-1 {
    top: -10%; left: -10%; width: 600px; height: 600px;
    background: radial-gradient(circle, rgba(167,207,235,0.6) 0%, rgba(253,252,248,0) 70%);
    animation-delay: 0s;
}
.wash-2 {
    bottom: 10%; right: -5%; width: 800px; height: 500px;
    background: radial-gradient(circle, rgba(116,172,223,0.4) 0%, rgba(253,252,248,0) 70%);
    animation-delay: -5s;
}
.wash-3 {
    top: 40%; left: 30%; width: 500px; height: 500px;
    background: radial-gradient(circle, rgba(226,240,249,0.8) 0%, rgba(253,252,248,0) 70%);
    animation-delay: -10s;
}

@keyframes floatWash {
    0% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(30px, 20px) scale(1.1); }
    100% { transform: translate(-20px, 40px) scale(0.9); }
}

/* Subtle Plane Silhouette in Negative Space */
.hero-plane-silhouette {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    width: 600px;
    height: 600px;
    z-index: 1;
    opacity: 0.05; /* Very subtle */
    pointer-events: none;
}
.hero-plane-silhouette polygon {
    fill: #4a90e2;
}

.hero-content { 
    z-index: 20; 
    max-width: 900px; 
    text-align: center;
    position: relative;
    margin-top: 20px;
}

.hero-title {
    font-size: 46px; 
    font-weight: 300;
    margin-bottom: 25px;
    color: var(--wc-text-main);
    letter-spacing: 2px;
    line-height: 1.4;
}
.hero-title span {
    position: relative;
    display: inline-block;
}
/* Watercolor highlight behind text */
.hero-title span::before {
    content: '';
    position: absolute;
    bottom: 5px; left: -5px; right: -5px; height: 15px;
    background: var(--wc-blue-light);
    z-index: -1;
    border-radius: 10px;
    transform: rotate(-1deg);
}

.hero p { 
    font-size: 18px; 
    margin-bottom: 45px; 
    color: var(--wc-text-muted);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    font-weight: 300;
}

.hero-buttons { display: flex; gap: 25px; justify-content: center; margin-bottom: 60px; flex-wrap: wrap; }

.btn-primary { 
    padding: 15px 35px; 
    font-size: 16px; 
    font-weight: 400; 
    color: #fff; 
    background: var(--wc-blue-dark);
    border: none;
    border-radius: 30px;
    transition: all 0.4s ease;
    box-shadow: 0 8px 20px rgba(74, 144, 226, 0.3);
    letter-spacing: 1px;
}
.btn-primary:hover { 
    transform: translateY(-3px);
    background: #3182ce;
    box-shadow: 0 12px 25px rgba(74, 144, 226, 0.4);
}

.btn-outline { 
    padding: 15px 35px; 
    font-size: 16px; 
    font-weight: 400; 
    color: var(--wc-blue-dark); 
    background: var(--wc-bg-white);
    border: 1px solid rgba(74, 144, 226, 0.2);
    border-radius: 30px;
    transition: all 0.4s ease;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.03);
    letter-spacing: 1px;
}
.btn-outline:hover { 
    transform: translateY(-3px);
    background: #fff;
    border-color: rgba(74, 144, 226, 0.4);
    box-shadow: 0 12px 25px rgba(74, 144, 226, 0.1);
}

.hero-images { 
    display: flex; 
    justify-content: center; 
    gap: 30px; 
    align-items: flex-end; 
    margin-top: 10px;
    z-index: 20;
}
.hero-images img { 
    max-width: 28%; 
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
    transition: all 0.5s cubic-bezier(0.25, 0.8, 0.25, 1); 
    /* Soft border blending into background */
    border: 6px solid rgba(255,255,255,0.8);
}
.hero-images img:nth-child(2) {
    transform: translateY(-20px);
    z-index: 2;
    box-shadow: 0 25px 50px rgba(74, 144, 226, 0.15);
}
.hero-images img:hover { 
    transform: translateY(-30px) scale(1.03); 
    box-shadow: 0 30px 60px rgba(74, 144, 226, 0.2);
}

/* Features Section */
.features { padding: 100px 5%; position: relative; z-index: 10; background: rgba(255,255,255,0.4); backdrop-filter: blur(2px);}
.section-title { 
    text-align: center; 
    font-size: 32px; 
    margin-bottom: 70px; 
    font-weight: 300;
    color: var(--wc-text-main);
    letter-spacing: 2px;
    position: relative;
}
.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: var(--wc-blue-mid);
    margin: 20px auto 0;
    border-radius: 2px;
}

.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; max-width: 1200px; margin: 0 auto; }

.feature-card { 
    padding: 45px 35px; 
    background: var(--wc-bg-white);
    border-radius: 20px;
    transition: all 0.4s ease; 
    position: relative;
    box-shadow: 0 10px 30px rgba(0,0,0,0.02);
    text-align: center;
    border: 1px solid rgba(255,255,255,0.5);
}
.feature-card:hover { 
    transform: translateY(-10px); 
    box-shadow: 0 20px 40px rgba(116, 172, 223, 0.15);
    background: #fff;
}
.feature-card h3 { 
    font-size: 20px; 
    margin-bottom: 20px; 
    color: var(--wc-blue-dark);
    font-weight: 400;
}
.feature-card p { color: var(--wc-text-muted); font-size: 15px; font-weight: 300; line-height: 1.8;}

/* Blog Section */
.blog { padding: 100px 5%; position: relative;}
.blog-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 50px; max-width: 1100px; margin: 0 auto; }
.blog-card { 
    display: flex; 
    flex-direction: column; 
    background: #fff;
    border-radius: 20px;
    transition: all 0.4s ease;
    overflow: hidden;
    box-shadow: 0 15px 35px rgba(0,0,0,0.04);
}
.blog-card:hover { 
    transform: translateY(-10px);
    box-shadow: 0 25px 50px rgba(116, 172, 223, 0.15);
}
.blog-card img { 
    width: 100%; height: 280px; object-fit: cover; 
    transition: transform 0.5s ease;
}
.blog-card:hover img { transform: scale(1.05); }
.blog-content { padding: 40px; position: relative; background: #fff; z-index: 2;}
.blog-date { display: inline-block; margin-bottom: 15px; font-size: 13px; color: var(--wc-blue-dark); font-weight: 400; letter-spacing: 1px;}
.blog-content h3 { font-size: 22px; margin-bottom: 15px; color: var(--wc-text-main); font-weight: 400;}
.blog-content p { color: var(--wc-text-muted); margin-bottom: 0; font-size: 15px; font-weight: 300;}
.btn-more { 
    display: block; 
    width: 200px; 
    margin: 70px auto 0; 
    text-align: center; 
    padding: 15px; 
    background: transparent;
    color: var(--wc-blue-dark); 
    font-weight: 400; 
    border: 1px solid rgba(74, 144, 226, 0.3);
    border-radius: 30px;
    transition: all 0.4s ease; 
    letter-spacing: 1px;
}
.btn-more:hover { 
    background: var(--wc-blue-light); 
    border-color: transparent;
    color: var(--wc-blue-dark);
}

/* FAQ Section */
.faq { padding: 100px 5%; max-width: 900px; margin: 0 auto; background: var(--wc-bg-white); margin-top: 40px; margin-bottom: 80px; border-radius: 24px; box-shadow: 0 20px 50px rgba(0,0,0,0.03);}
.faq-item { 
    margin-bottom: 20px; 
    padding: 30px; 
    border-radius: 16px;
    background: #fff;
    transition: all 0.3s ease;
    border: 1px solid rgba(0,0,0,0.02);
}
.faq-item:hover {
    box-shadow: 0 10px 25px rgba(116, 172, 223, 0.1);
    transform: translateX(5px);
}
.faq-question { font-size: 18px; font-weight: 400; margin-bottom: 15px; color: var(--wc-text-main);}
.faq-answer { color: var(--wc-text-muted); font-size: 15px; font-weight: 300; line-height: 1.8;}

/* Footer */
.footer { background: #2d3748; padding: 80px 5% 40px; color: #a0aec0; position: relative; overflow: hidden;}
/* Subtle watercolor effect in footer */
.footer::before {
    content: ''; position: absolute; top: -50%; right: -10%; width: 500px; height: 500px;
    background: radial-gradient(circle, rgba(74, 144, 226, 0.1) 0%, transparent 70%);
    border-radius: 50%; filter: blur(2px);
}
.footer-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 50px; max-width: 1200px; margin: 0 auto 60px; position: relative; z-index: 1;}
.footer-col h4 { font-size: 16px; color: #fff; margin-bottom: 30px; font-weight: 400; letter-spacing: 1px;}
.footer-col ul li { margin-bottom: 15px; font-size: 14px;}
.footer-col ul li a { color: #a0aec0; transition: all 0.3s ease; font-weight: 300;}
.footer-col ul li a:hover { color: #ebf8ff; padding-left: 5px;}
.footer-bottom { text-align: center; padding-top: 30px; border-top: 1px solid rgba(255,255,255,0.05); font-size: 13px; font-weight: 300; position: relative; z-index: 1;}

/* Download Page Grid */
.download-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 40px; max-width: 1100px; margin: 80px auto; padding: 0 5%; }
.download-card { 
    padding: 50px 40px; 
    text-align: center; 
    background: #fff; 
    border-radius: 24px;
    box-shadow: 0 15px 40px rgba(0,0,0,0.04);
    transition: all 0.4s ease;
    border: 1px solid rgba(255,255,255,0.8);
}
.download-card:hover { 
    transform: translateY(-10px);
    box-shadow: 0 25px 50px rgba(116, 172, 223, 0.15);
}
.download-card h3 { font-size: 22px; margin-bottom: 20px; color: var(--wc-text-main); font-weight: 400;}
.download-card p { color: var(--wc-text-muted); margin-bottom: 35px; font-size: 15px; font-weight: 300; line-height: 1.8;}
.btn-dl-card { 
    display: inline-block; 
    padding: 14px 30px; 
    background: var(--wc-blue-dark);
    color: #fff; 
    font-weight: 400; 
    border-radius: 30px;
    transition: all 0.3s ease; 
    letter-spacing: 1px;
    box-shadow: 0 6px 15px rgba(74, 144, 226, 0.2);
}
.btn-dl-card:hover { 
    background: #3182ce; 
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(74, 144, 226, 0.4);
}

/* Page specific headers */
.page-header { 
    padding: 100px 5% 80px; 
    text-align: center; 
    position: relative;
}
.page-header::before {
    content: ''; position: absolute; top: 0; left: 50%; transform: translateX(-50%);
    width: 600px; height: 300px; background: radial-gradient(circle, rgba(167, 207, 235, 0.3) 0%, transparent 70%);
    border-radius: 50%; filter: blur(2px); z-index: -1;
}
.page-header-content {
    max-width: 800px;
    margin: 0 auto;
}
.page-header h1 { 
    font-size: 42px; 
    margin-bottom: 20px; 
    color: var(--wc-text-main);
    font-weight: 300;
    letter-spacing: 2px;
}
.page-header p { font-size: 18px; color: var(--wc-text-muted); font-weight: 300;}

/* === perf: reduce motion & lower GPU cost === */
.feature-card,
.blog-card,
.hero-content,
.glass-panel,
.pearl-card {
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
}
.navbar {
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation: none !important;
        transition: none !important;
        scroll-behavior: auto !important;
    }
}

/* perf: limit decorative infinite layers on mid/low-end devices */
@media (max-width: 768px) {
    .bubble:nth-child(n+3),
    .tiny-plane:nth-child(n+3),
    .bg-shard:nth-child(n+4),
    .orb:nth-child(n+2) {
        display: none !important;
    }
}