/* Reset & Base */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif; background: #0f0a18; color: #e0d8ea; line-height: 1.6; min-height: 100vh; background-image: radial-gradient(circle at center, #1a112c 0%, #0f0a18 100%); }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* RPG Theme Variables */
:root {
    --rpg-gold: #e2b714;
    --rpg-gold-glow: rgba(226, 183, 20, 0.6);
    --rpg-purple: #5a4b7d;
    --rpg-dark: #120c1c;
    --rpg-card: linear-gradient(135deg, #2a1b3d 0%, #1a0b2e 100%);
    --rpg-text: #e0d8ea;
}

.rpg-font { font-family: 'Georgia', serif; font-weight: bold; letter-spacing: 1px; }

/* Navigation */
.navbar { display: flex; justify-content: space-between; align-items: center; padding: 15px 5%; background: rgba(18, 12, 28, 0.95); border-bottom: 2px solid var(--rpg-purple); position: sticky; top: 0; z-index: 100; box-shadow: 0 4px 15px rgba(0,0,0,0.5); backdrop-filter: blur(2px); }
.nav-logo { font-size: 26px; color: var(--rpg-gold); text-shadow: 0 0 10px var(--rpg-gold-glow); display: flex; align-items: center; gap: 10px; }
.nav-links { display: flex; gap: 30px; align-items: center; }
.nav-links a { font-size: 16px; transition: all 0.3s; color: var(--rpg-text); }
.nav-links a:hover { color: var(--rpg-gold); text-shadow: 0 0 8px var(--rpg-gold-glow); }
.btn-download-nav { padding: 8px 22px; background: var(--rpg-card); border: 1px solid var(--rpg-gold); border-radius: 4px; color: var(--rpg-gold) !important; box-shadow: 0 0 10px var(--rpg-gold-glow) inset; transition: all 0.3s; }
.btn-download-nav:hover { background: var(--rpg-gold); color: var(--rpg-dark) !important; box-shadow: 0 0 15px var(--rpg-gold); }

/* Hero Section */
.hero { position: relative; padding: 80px 5% 60px; text-align: center; overflow: hidden; min-height: 85vh; display: flex; flex-direction: column; justify-content: center; align-items: center; }
.hero::before { content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 100%; background: url('data:image/svg+xml;utf8,<svg width="60" height="60" viewBox="0 0 60 60" xmlns="http://www.w3.org/2000/svg"><path d="M30 0l30 30-30 30L0 30z" fill="none" stroke="rgba(90,75,125,0.1)" stroke-width="1"/></svg>'); z-index: 0; }
.hero-content { z-index: 2; max-width: 900px; margin: 0 auto; position: relative; }

.hero h1 { font-size: 42px; margin-bottom: 20px; color: var(--rpg-gold); text-shadow: 0 0 20px var(--rpg-gold-glow); line-height: 1.4; }
.hero p { font-size: 18px; margin-bottom: 40px; color: #b8a9c9; }

.hero-buttons { display: flex; gap: 20px; justify-content: center; margin-bottom: 50px; flex-wrap: wrap; }
.btn-rpg { padding: 15px 35px; font-size: 18px; background: var(--rpg-card); color: var(--rpg-gold); border: 2px solid var(--rpg-gold); box-shadow: 0 0 15px var(--rpg-gold-glow) inset, 0 5px 15px rgba(0,0,0,0.6); transition: all 0.3s; border-radius: 6px; cursor: pointer; text-transform: uppercase; }
.btn-rpg:hover { transform: translateY(-3px); box-shadow: 0 0 25px var(--rpg-gold-glow) inset, 0 8px 20px rgba(0,0,0,0.8); background: rgba(226, 183, 20, 0.1); }
.btn-pc { background: var(--rpg-gold); color: var(--rpg-dark); box-shadow: 0 0 20px var(--rpg-gold-glow); }
.btn-pc:hover { background: #f3c825; color: var(--rpg-dark); box-shadow: 0 0 30px var(--rpg-gold); }

.hero-images { display: flex; justify-content: center; gap: 20px; margin-top: 20px; z-index: 1; align-items: flex-end; }
.hero-images img { max-width: 30%; border: 2px solid var(--rpg-purple); border-radius: 8px; box-shadow: 0 10px 30px rgba(0,0,0,0.8); transition: all 0.4s ease; }
.hero-images img:hover { transform: translateY(-15px) scale(1.02); border-color: var(--rpg-gold); box-shadow: 0 15px 40px var(--rpg-gold-glow); }

/* Features Section - RPG Skill Tree */
.features { padding: 100px 5%; background: #0b0712; border-top: 2px solid var(--rpg-purple); border-bottom: 2px solid var(--rpg-purple); position: relative; }
.section-title { text-align: center; font-size: 38px; margin-bottom: 80px; color: var(--rpg-gold); text-shadow: 0 0 15px var(--rpg-gold-glow); }
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 50px; max-width: 1100px; margin: 0 auto; position: relative; }

/* Skill Tree Connecting Lines */
.tree-lines { position: absolute; top: 0; left: 0; right: 0; bottom: 0; z-index: 1; pointer-events: none; }
@media (min-width: 769px) {
    .line-v1 { position: absolute; left: 16.66%; top: 16.66%; bottom: 16.66%; width: 3px; background: var(--rpg-purple); box-shadow: 0 0 10px var(--rpg-purple); z-index: 1; }
    .line-h1 { position: absolute; top: 16.66%; left: 16.66%; right: 16.66%; height: 3px; background: var(--rpg-purple); box-shadow: 0 0 10px var(--rpg-purple); z-index: 1; }
    .line-h2 { position: absolute; top: 50%; left: 16.66%; right: 16.66%; height: 3px; background: var(--rpg-purple); box-shadow: 0 0 10px var(--rpg-purple); z-index: 1; }
    .line-h3 { position: absolute; top: 83.33%; left: 16.66%; width: 33.33%; height: 3px; background: var(--rpg-purple); box-shadow: 0 0 10px var(--rpg-purple); z-index: 1; }
    .line-v3 { position: absolute; right: 16.66%; top: 50%; bottom: 16.66%; width: 3px; background: var(--rpg-purple); box-shadow: 0 0 10px var(--rpg-purple); z-index: 1; }
}

.feature-card { background: var(--rpg-card); padding: 35px 25px; border: 2px solid var(--rpg-purple); border-radius: 12px; box-shadow: 0 8px 20px rgba(0,0,0,0.6); transition: all 0.3s; text-align: center; position: relative; z-index: 2; }
.feature-card::before { content: ''; position: absolute; top: -5px; left: -5px; right: -5px; bottom: -5px; border: 1px solid rgba(226, 183, 20, 0); border-radius: 16px; transition: all 0.3s; pointer-events: none; }
.feature-card:hover { transform: translateY(-5px); border-color: var(--rpg-gold); box-shadow: 0 10px 30px var(--rpg-gold-glow), inset 0 0 20px rgba(226, 183, 20, 0.1); }
.feature-card:hover::before { border-color: rgba(226, 183, 20, 0.4); }
.feature-card h3 { font-size: 22px; margin-bottom: 15px; color: var(--rpg-gold); }
.feature-card p { color: #b8a9c9; font-size: 14px; line-height: 1.7; }

/* Root Node Highlight */
.feature-card.root-node { border-color: var(--rpg-gold); box-shadow: 0 0 20px var(--rpg-gold-glow); }
.feature-card.root-node h3 { text-shadow: 0 0 10px var(--rpg-gold); }

/* Blog Section */
.blog { padding: 100px 5%; background: #150e1f; color: var(--rpg-text); }
.blog-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 40px; max-width: 1100px; margin: 0 auto; }
.blog-card { background: var(--rpg-card); border: 1px solid var(--rpg-purple); border-radius: 8px; box-shadow: 0 10px 25px rgba(0,0,0,0.5); transition: all 0.3s; display: flex; flex-direction: column; overflow: hidden; }
.blog-card:hover { transform: translateY(-5px); border-color: var(--rpg-gold); box-shadow: 0 15px 35px rgba(0,0,0,0.7); }
.blog-card img { width: 100%; height: 260px; object-fit: cover; border-bottom: 2px solid var(--rpg-purple); opacity: 0.85; transition: opacity 0.3s; }
.blog-card:hover img { opacity: 1; }
.blog-content { padding: 30px; }
.blog-date { display: inline-block; color: var(--rpg-gold); font-size: 14px; margin-bottom: 15px; letter-spacing: 1px; }
.blog-content h3 { font-size: 22px; margin-bottom: 15px; color: #fff; }
.blog-content p { color: #b8a9c9; margin-bottom: 0; }
.btn-more { display: block; width: 220px; margin: 60px auto 0; text-align: center; padding: 14px; background: transparent; color: var(--rpg-gold); border: 2px solid var(--rpg-gold); border-radius: 4px; transition: all 0.3s; }
.btn-more:hover { background: var(--rpg-gold); color: var(--rpg-dark); box-shadow: 0 0 20px var(--rpg-gold-glow); }

/* FAQ Section */
.faq { padding: 100px 5%; max-width: 900px; margin: 0 auto; }
.faq-item { background: var(--rpg-card); margin-bottom: 20px; border: 1px solid var(--rpg-purple); border-radius: 8px; padding: 25px 30px; transition: all 0.3s; }
.faq-item:hover { border-color: var(--rpg-gold); box-shadow: 0 5px 20px rgba(0,0,0,0.5); }
.faq-question { font-size: 18px; font-weight: bold; color: var(--rpg-gold); margin-bottom: 15px; display: flex; align-items: center; gap: 10px; }
.faq-question::before { content: '✦'; color: var(--rpg-purple); }
.faq-answer { color: #b8a9c9; line-height: 1.8; font-size: 15px; padding-left: 28px; }

/* Footer */
.footer { background: #08050d; padding: 80px 5% 30px; border-top: 2px solid var(--rpg-purple); }
.footer-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 40px; max-width: 1100px; margin: 0 auto 50px; }
.footer-col h4 { font-size: 18px; color: var(--rpg-gold); margin-bottom: 25px; }
.footer-col ul li { margin-bottom: 12px; }
.footer-col ul li a { color: #8a7a9e; transition: color 0.3s; }
.footer-col ul li a:hover { color: var(--rpg-gold); }
.footer-bottom { text-align: center; padding-top: 30px; border-top: 1px solid rgba(90, 75, 125, 0.3); color: #5a4b7d; font-size: 14px; }

/* Page specific headers */
.page-header { padding: 100px 5% 60px; text-align: center; background: #0b0712; border-bottom: 2px solid var(--rpg-purple); position: relative; }
.page-header::before { content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 100%; background: url('data:image/svg+xml;utf8,<svg width="60" height="60" viewBox="0 0 60 60" xmlns="http://www.w3.org/2000/svg"><path d="M30 0l30 30-30 30L0 30z" fill="none" stroke="rgba(226,183,20,0.05)" stroke-width="1"/></svg>'); z-index: 0; }
.page-header h1 { font-size: 38px; color: var(--rpg-gold); margin-bottom: 20px; text-shadow: 0 0 15px var(--rpg-gold-glow); position: relative; z-index: 1; line-height: 1.4; }
.page-header p { color: #b8a9c9; font-size: 18px; max-width: 600px; margin: 0 auto; position: relative; z-index: 1; }

/* Download Page Grid */
.download-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 30px; max-width: 1100px; margin: 60px auto; padding: 0 5%; }
.download-card { background: var(--rpg-card); border: 2px solid var(--rpg-purple); border-radius: 12px; padding: 40px 25px; text-align: center; transition: all 0.3s; }
.download-card:hover { transform: translateY(-8px); border-color: var(--rpg-gold); box-shadow: 0 15px 30px rgba(0,0,0,0.6); }
.download-card h3 { color: var(--rpg-gold); font-size: 24px; margin-bottom: 15px; }
.download-card p { color: #b8a9c9; margin-bottom: 30px; font-size: 15px; }
.download-card .btn-rpg { display: inline-block; padding: 12px 30px; font-size: 16px; }

/* Responsive adjustments for Tree */
@media (max-width: 768px) {
    .features-grid { grid-template-columns: 1fr; gap: 20px; }
    .tree-lines { display: none; }
}

/* === 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;
    }
}