:root {
    --bg-main: #F9F9F6;
    --card-bg: #FFFFFF;
    --primary: #00B49F;
    --primary-light: rgba(0, 180, 159, 0.1);
    --secondary: #FF7052;
    --text-dark: #2C3E50;
    --text-muted: #7F8C8D;
    --border-color: #EAECEE;
    --shadow-soft: 0 10px 30px rgba(0,0,0,0.03);
    --shadow-glow: 0 20px 40px rgba(0, 180, 159, 0.15);
}

html { scroll-behavior: smooth; }
* { margin: 0; padding: 0; box-sizing: border-box; }
[id] { scroll-margin-top: 100px; }

body {
    background: var(--bg-main);
    color: var(--text-dark);
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

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

/* Hidden inputs for CSS Logic */
input[type="radio"].css-logic { display: none; }

/* Navigation */
header {
    background: rgba(249, 249, 246, 0.9);
    backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}
.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
}
.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}
.nav-links {
    display: flex;
    gap: 20px;
    list-style: none;
}
.nav-links a {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}
.nav-links a:hover { color: var(--primary); }

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 30px;
    font-weight: 600;
    text-decoration: none;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}
.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 4px 15px rgba(0, 180, 159, 0.2);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 180, 159, 0.3);
    background: #00a08e;
}
.btn-secondary {
    background: transparent;
    color: var(--secondary);
    border: 1px solid var(--secondary);
}
.btn-secondary:hover {
    background: var(--secondary);
    color: #fff;
    box-shadow: 0 4px 15px rgba(255, 112, 82, 0.2);
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 100px 20px 60px;
}
.hero h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
    color: var(--text-dark);
    letter-spacing: -0.5px;
}
.hero p {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 40px;
}
.cta-group {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 60px;
}

/* Interactive Speed Scenario Switcher */
.scenario-widget {
    background: var(--card-bg);
    border-radius: 24px;
    padding: 30px;
    box-shadow: var(--shadow-soft);
    max-width: 600px;
    margin: 0 auto;
    border: 1px solid var(--border-color);
}
.scenario-tabs {
    display: flex;
    position: relative;
    background: var(--bg-main);
    border-radius: 40px;
    padding: 6px;
    margin-bottom: 30px;
}
.scenario-tabs label {
    flex: 1;
    text-align: center;
    padding: 12px;
    cursor: pointer;
    z-index: 2;
    font-weight: 600;
    color: var(--text-muted);
    transition: color 0.4s;
    font-size: 0.95rem;
}
.tab-indicator {
    position: absolute;
    top: 6px; left: 6px; bottom: 6px;
    width: calc(25% - 3px);
    background: var(--card-bg);
    border-radius: 30px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    transition: transform 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    z-index: 1;
}
#sc-web:checked ~ .scenario-tabs .tab-indicator { transform: translateX(0); }
#sc-4k:checked ~ .scenario-tabs .tab-indicator { transform: translateX(100%); }
#sc-game:checked ~ .scenario-tabs .tab-indicator { transform: translateX(200%); }
#sc-work:checked ~ .scenario-tabs .tab-indicator { transform: translateX(300%); }

#sc-web:checked ~ .scenario-tabs label[for="sc-web"],
#sc-4k:checked ~ .scenario-tabs label[for="sc-4k"],
#sc-game:checked ~ .scenario-tabs label[for="sc-game"],
#sc-work:checked ~ .scenario-tabs label[for="sc-work"] { color: var(--primary); }

.gauge-display {
    position: relative;
    height: 120px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}
.gauge-value {
    position: absolute;
    font-size: 4.5rem;
    font-weight: 800;
    color: var(--primary);
    opacity: 0;
    transform: scale(0.9) translateY(10px);
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    top: -20px;
}
.unit { font-size: 1.5rem; font-weight: 500; color: var(--text-muted); margin-left: 4px; }
.gauge-label { position: absolute; bottom: 10px; color: var(--text-muted); font-size: 1rem; display: flex; align-items: center; gap: 8px;}

#sc-web:checked ~ .gauge-display .val-web,
#sc-4k:checked ~ .gauge-display .val-4k,
#sc-game:checked ~ .gauge-display .val-game,
#sc-work:checked ~ .gauge-display .val-work { opacity: 1; transform: scale(1) translateY(0); }

/* Feature Grid */
.features-section { padding: 80px 0; }
.section-title { text-align: center; font-size: 2.5rem; margin-bottom: 50px; font-weight: 700; color: var(--text-dark); }
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}
.feature-card {
    background: var(--card-bg);
    border-radius: 24px;
    padding: 40px;
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(0, 180, 159, 0.04);
    transition: transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.6s ease;
}
.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-glow);
}
.feature-icon {
    width: 48px;
    height: 48px;
    color: var(--primary);
    margin-bottom: 24px;
}
.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 16px;
    color: var(--text-dark);
}
.feature-card p { color: var(--text-muted); }

/* Streaming & AI Cards */
.media-ai-section { padding: 20px 0 60px; }
.two-col-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}
.graphic-card {
    background: var(--card-bg);
    border-radius: 24px;
    padding: 40px;
    box-shadow: var(--shadow-soft);
    border: 1px solid var(--border-color);
    transition: transform 0.5s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.5s;
}
.graphic-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-glow);
}
.streaming-card { border-top: 4px solid var(--secondary); }
.ai-card { border-top: 4px solid var(--primary); }
.graphic-card h3 { font-size: 1.75rem; margin-bottom: 16px; color: var(--text-dark); }
.graphic-card p { color: var(--text-muted); margin-bottom: 30px; font-size: 1.1rem; line-height: 1.6; }
.tags { display: flex; gap: 10px; flex-wrap: wrap; }
.tags span {
    padding: 6px 16px;
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--text-dark);
    font-weight: 500;
}

/* Pricing Grid */
.pricing-section { padding: 60px 0 80px; }
.pricing-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.pricing-card { background: var(--card-bg); border-radius: 24px; padding: 40px; box-shadow: var(--shadow-soft); text-align: center; border: 1px solid var(--border-color); }
.pricing-card.popular { border: 2px solid var(--primary); transform: scale(1.05); box-shadow: var(--shadow-glow); position: relative; }
.badge { position: absolute; top: -14px; left: 50%; transform: translateX(-50%); background: var(--secondary); color: #fff; padding: 4px 16px; border-radius: 20px; font-size: 0.85rem; font-weight: 600; }
.pricing-card h3 { font-size: 1.5rem; margin-bottom: 10px; }
.price { font-size: 3rem; font-weight: 800; color: var(--text-dark); margin-bottom: 30px; }
.price span { font-size: 1rem; font-weight: normal; color: var(--text-muted); }
.pricing-list { list-style: none; text-align: left; margin-bottom: 30px; }
.pricing-list li { padding: 12px 0; border-bottom: 1px solid var(--border-color); color: var(--text-muted); display: flex; align-items: center; gap: 10px;}
.pricing-list li svg { width: 18px; height: 18px; color: var(--primary); flex-shrink: 0; }
.pricing-card .btn { width: 100%; display: block; }

/* Reviews Section */
.reviews-section { padding: 80px 0; background: var(--card-bg); border-top: 1px solid var(--border-color); border-bottom: 1px solid var(--border-color); margin: 40px 0; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.review-card { background: var(--bg-main); padding: 30px; border-radius: 20px; border: 1px solid var(--border-color); box-shadow: inset 0 2px 4px rgba(0,0,0,0.02); }
.review-card p { font-style: italic; color: var(--text-muted); margin-bottom: 20px; font-size: 1.05rem; line-height: 1.8; }
.review-card .author { font-weight: 600; color: var(--text-dark); text-align: right; }

/* FAQ Section */
.faq-section { padding: 40px 0 80px; }
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { background: var(--card-bg); border-radius: 16px; border: 1px solid var(--border-color); margin-bottom: 16px; box-shadow: var(--shadow-soft); transition: box-shadow 0.3s; }
.faq-item:hover { box-shadow: var(--shadow-glow); }
.faq-item summary { padding: 20px 24px; font-size: 1.1rem; font-weight: 600; cursor: pointer; list-style: none; display: flex; justify-content: space-between; align-items: center; color: var(--text-dark); outline: none; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: '+'; font-size: 1.5rem; color: var(--primary); transition: transform 0.3s; }
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { padding: 0 24px 24px; color: var(--text-muted); line-height: 1.7; border-top: 1px dashed var(--border-color); margin-top: 10px; padding-top: 20px; }

/* Subpages */
.page-header { background: var(--card-bg); padding: 80px 20px; border-bottom: 1px solid var(--border-color); text-align: center; }
.page-header h1 { font-size: 2.5rem; color: var(--text-dark); }
.content-box { background: var(--card-bg); padding: 60px; border-radius: 24px; box-shadow: var(--shadow-soft); margin: 60px auto; max-width: 900px; border: 1px solid var(--border-color); }
.content-box h2 { font-size: 1.75rem; color: var(--primary); margin: 40px 0 20px; }
.content-box p { font-size: 1.1rem; color: var(--text-muted); margin-bottom: 20px; }
.content-box ul { padding-left: 20px; margin-bottom: 20px; }
.content-box li { color: var(--text-muted); margin-bottom: 10px; font-size: 1.1rem; }

/* Blog & Article Styles */
.blog-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px; margin-top: 40px; }
.blog-card { background: var(--card-bg); border-radius: 20px; padding: 30px; border: 1px solid var(--border-color); box-shadow: var(--shadow-soft); transition: transform 0.3s; }
.blog-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-glow); }
.blog-card h3 { font-size: 1.4rem; margin-bottom: 15px; line-height: 1.4; color: var(--text-dark); }
.blog-card p { color: var(--text-muted); margin-bottom: 20px; font-size: 1.05rem; }
.read-more { color: var(--primary); font-weight: 600; text-decoration: none; display: inline-flex; align-items: center; gap: 5px; }

.article-layout { max-width: 900px; margin: 40px auto 80px; background: var(--card-bg); padding: 60px; border-radius: 24px; box-shadow: var(--shadow-soft); border: 1px solid var(--border-color); }
.article-title { font-size: 2.5rem; color: var(--text-dark); line-height: 1.3; margin-bottom: 20px; font-weight: 800;}
.article-meta { color: var(--text-muted); font-size: 1rem; margin-bottom: 40px; border-bottom: 1px solid var(--border-color); padding-bottom: 20px; display: flex; gap: 20px; }
.toc { background: var(--bg-main); padding: 30px; border-radius: 16px; margin-bottom: 40px; border: 1px solid var(--border-color); }
.toc h4 { margin-bottom: 15px; color: var(--text-dark); font-size: 1.2rem; }
.toc ul { list-style: none; padding-left: 0; }
.toc ul li { margin-bottom: 10px; }
.toc ul li a { color: var(--primary); text-decoration: none; font-size: 1.05rem;}
.toc ul li a:hover { text-decoration: underline; }
.article-content h2 { font-size: 1.8rem; color: var(--text-dark); margin: 40px 0 20px; border-bottom: 2px solid var(--primary-light); padding-bottom: 10px; }
.article-content h3 { font-size: 1.4rem; color: var(--text-dark); margin: 30px 0 15px; }
.article-content p { font-size: 1.15rem; color: var(--text-muted); line-height: 1.8; margin-bottom: 20px; }
.article-content a { color: var(--primary); text-decoration: none; font-weight: 500; }
.article-content a:hover { text-decoration: underline; }
.article-content strong { color: var(--text-dark); }
.article-content ul, .article-content ol { padding-left: 20px; margin-bottom: 20px; font-size: 1.15rem; color: var(--text-muted); line-height: 1.8;}
.article-content li { margin-bottom: 10px; }
.faq-box { margin-top: 60px; padding-top: 40px; border-top: 1px dashed var(--border-color); }
.related-reading { margin-top: 40px; background: var(--bg-main); padding: 30px; border-radius: 16px; }
.related-reading h3 { margin-bottom: 20px; color: var(--text-dark); font-size: 1.3rem;}
.related-reading ul { list-style: circle; padding-left: 20px; }
.related-reading li { margin-bottom: 12px; }
.related-reading a { color: var(--text-dark); text-decoration: none; font-size: 1.1rem; line-height: 1.6; }
.related-reading a:hover { color: var(--primary); text-decoration: underline;}

/* Footer */
footer { background: var(--card-bg); padding: 60px 20px; text-align: center; border-top: 1px solid var(--border-color); }
.footer-links { display: flex; justify-content: center; gap: 30px; margin-bottom: 24px; }
.footer-links a { color: var(--text-muted); text-decoration: none; font-weight: 500; transition: color 0.3s; }
.footer-links a:hover { color: var(--primary); }
.copyright { color: var(--text-muted); font-size: 0.95rem; }

/* Media Queries */
@media (max-width: 900px) {
    .feature-grid, .two-col-grid, .pricing-grid, .grid-3, .blog-grid { grid-template-columns: 1fr; }
    .pricing-card.popular { transform: none; }
    .nav-links { display: none; }
    .cta-group { flex-direction: column; }
    .content-box, .article-layout { padding: 30px 20px; margin: 30px 10px; }
    .article-title { font-size: 2rem; }
}