/* ============================================================
   CSharpSkin - 产品官网样式（Fluent Design 浅色风格）
   ============================================================ */

/* ---------- Reset & Variables ---------- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #60a5fa;
    --primary-bg: #eff6ff;
    --accent: #7c3aed;
    --accent-light: #a78bfa;
    --bg: #f8fafc;
    --bg-white: #ffffff;
    --bg-card: #ffffff;
    --bg-card-hover: #f1f5f9;
    --bg-code: #1e293b;
    --text: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;
    --text-dim: #94a3b8;
    --text-inverse: #f1f5f9;
    --border: #e2e8f0;
    --border-light: #cbd5e1;
    --border-dark: #94a3b8;
    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 20px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow: 0 2px 12px rgba(0,0,0,0.06);
    --shadow-lg: 0 12px 40px rgba(0,0,0,0.08);
    --shadow-blue: 0 4px 20px rgba(37,99,235,0.15);
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --max-width: 1200px;
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
}

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
a { color: inherit; text-decoration: none; transition: var(--transition); }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 10px 24px; border-radius: var(--radius-sm); font-weight: 600;
    font-size: 0.9rem; cursor: pointer; transition: var(--transition);
    border: none; white-space: nowrap; font-family: inherit;
}
.btn-lg { padding: 14px 32px; font-size: 1rem; }
.btn-primary {
    background: var(--primary); color: #fff;
    box-shadow: var(--shadow-blue);
}
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); box-shadow: 0 8px 28px rgba(37,99,235,0.25); }
.btn-ghost { color: var(--text-secondary); background: var(--bg-white); border: 1.5px solid var(--border-light); }
.btn-ghost:hover { color: var(--primary); border-color: var(--primary-light); background: var(--primary-bg); }
.btn-ghost-light { color: rgba(255,255,255,0.8); background: transparent; border: 1.5px solid rgba(255,255,255,0.3); }
.btn-ghost-light:hover { color: #fff; border-color: rgba(255,255,255,0.6); background: rgba(255,255,255,0.1); }
.btn-white { background: #fff; color: var(--primary-dark); }
.btn-white:hover { transform: translateY(-1px); box-shadow: 0 8px 24px rgba(0,0,0,0.15); }

/* ---------- Navbar ---------- */
.navbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    padding: 16px 0; transition: var(--transition);
}
.navbar.scrolled {
    background: rgba(255,255,255,0.85); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border); box-shadow: var(--shadow-sm);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.2rem; color: var(--text); flex-shrink: 0; }
.logo svg { flex-shrink: 0; }
.logo-img {  height: 50px; flex-shrink: 0; border-radius: 6px; object-fit: contain; }
.nav-links { display: flex; gap: 32px; }
.nav-links a { font-size: 0.9rem; color: var(--text-muted); position: relative; font-weight: 500; }
.nav-links a:hover { color: var(--primary); }
.nav-links a::after {
    content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 2px;
    background: var(--primary); transition: width 0.3s; border-radius: 1px;
}
.nav-links a:hover::after { width: 100%; }
.nav-actions { display: flex; gap: 12px; align-items: center; }
.mobile-toggle {
    display: none; flex-direction: column; gap: 5px; background: none;
    border: none; cursor: pointer; padding: 4px; flex-shrink: 0;
}
.mobile-toggle span { width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: var(--transition); }

/* ---------- Hero ---------- */
.hero {
    min-height: 100vh; display: flex; align-items: center; justify-content: center;
    position: relative; padding: 120px 0 80px; overflow: hidden;
    background: linear-gradient(180deg, var(--bg) 0%, #e0e7ff 100%);
}
.hero-bg { position: absolute; inset: 0; overflow: hidden; }
.hero-bg::before {
    content: ''; position: absolute; top: 10%; right: -10%;
    width: 600px; height: 600px; border-radius: 50%;
    background: radial-gradient(circle, rgba(37,99,235,0.08), transparent 70%);
    animation: float1 12s ease-in-out infinite;
}
.hero-bg::after {
    content: ''; position: absolute; bottom: 5%; left: -5%;
    width: 500px; height: 500px; border-radius: 50%;
    background: radial-gradient(circle, rgba(124,58,237,0.06), transparent 70%);
    animation: float2 10s ease-in-out infinite;
}
@keyframes float1 { 0%, 100% { transform: translate(0, 0); } 50% { transform: translate(-30px, 20px); } }
@keyframes float2 { 0%, 100% { transform: translate(0, 0); } 50% { transform: translate(20px, -30px); } }
.hero-grid {
    position: absolute; inset: 0;
    background-image:
        linear-gradient(rgba(37,99,235,0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37,99,235,0.04) 1px, transparent 1px);
    background-size: 48px 48px;
    -webkit-mask-image: radial-gradient(ellipse at center, black 20%, transparent 70%);
    mask-image: radial-gradient(ellipse at center, black 20%, transparent 70%);
}
.hero-content { position: relative; z-index: 2; text-align: center; max-width: 800px; }
.hero-badge {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 6px 20px; border-radius: 50px;
    background: var(--bg-white); border: 1px solid var(--border);
    font-size: 0.85rem; color: var(--primary); margin-bottom: 32px;
    box-shadow: var(--shadow-sm);
}
.badge-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); animation: dotBlink 2s ease-in-out infinite; }
@keyframes dotBlink { 0%, 100% { opacity: 1; } 50% { opacity: 0.3; } }
.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem); font-weight: 900;
    line-height: 1.15; margin-bottom: 24px; letter-spacing: -0.02em; color: var(--text);
}
.gradient-text {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.hero-desc { font-size: 1.15rem; color: var(--text-muted); max-width: 520px; margin: 0 auto 40px; line-height: 1.7; }
.hero-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin-bottom: 64px; }
.hero-stats { display: flex; align-items: center; justify-content: center; gap: 48px; }
.stat-item { text-align: center; }
.stat-number { font-size: 2.5rem; font-weight: 900; color: var(--text); display: block; line-height: 1; }
.stat-suffix { font-size: 1.2rem; font-weight: 700; color: var(--text); }
.stat-label { font-size: 0.85rem; color: var(--text-muted); margin-top: 6px; display: block; }
.stat-divider { width: 1px; height: 40px; background: var(--border-light); }
.hero-scroll {
    position: absolute; bottom: 32px; left: 50%; transform: translateX(-50%);
    display: flex; flex-direction: column; align-items: center; gap: 6px;
    font-size: 0.8rem; color: var(--text-dim); animation: scrollBounce 2s ease-in-out infinite;
}
@keyframes scrollBounce { 0%, 100% { transform: translateX(-50%) translateY(0); } 50% { transform: translateX(-50%) translateY(8px); } }

/* ---------- Section Common ---------- */
.section-header { text-align: center; margin-bottom: 64px; }
.section-tag {
    display: inline-block; font-size: 0.8rem; font-weight: 600; letter-spacing: 0.05em;
    text-transform: uppercase; color: var(--primary);
    background: var(--primary-bg); padding: 6px 16px; border-radius: 50px; margin-bottom: 16px;
}
.section-title { font-size: clamp(1.8rem, 3.5vw, 2.8rem); font-weight: 800; margin-bottom: 16px; color: var(--text); }
.section-desc { font-size: 1.05rem; color: var(--text-muted); max-width: 560px; margin: 0 auto; }

/* ---------- Features ---------- */
.features { padding: 120px 0; }
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.feature-card {
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 36px 28px;
    transition: var(--transition); position: relative; overflow: hidden;
    box-shadow: var(--shadow-sm);
}
.feature-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    opacity: 0; transition: opacity 0.3s;
}
.feature-card:hover { border-color: var(--border-light); transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.feature-card:hover::before { opacity: 1; }
.feature-icon {
    width: 56px; height: 56px; border-radius: var(--radius-sm);
    background: var(--primary-bg); display: flex; align-items: center;
    justify-content: center; margin-bottom: 20px; color: var(--primary); transition: var(--transition);
}
.feature-card:hover .feature-icon { background: rgba(37,99,235,0.15); }
.feature-card h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 10px; color: var(--text); }
.feature-card p { font-size: 0.9rem; color: var(--text-muted); line-height: 1.7; }

/* ---------- Preview / Demo Window ---------- */
.preview { padding: 80px 0 120px; background: var(--bg-white); }
.preview-window {
    max-width: 720px; margin: 0 auto; background: #fafbfc;
    border: 1px solid var(--border-light); border-radius: var(--radius);
    overflow: hidden; box-shadow: 0 16px 48px rgba(0,0,0,0.08);
}
.window-titlebar {
    display: flex; align-items: center; justify-content: space-between;
    padding: 12px 16px; background: #f1f5f9; border-bottom: 1px solid var(--border);
}
.window-dots { display: flex; gap: 8px; }
.window-dots span { width: 12px; height: 12px; border-radius: 50%; }
.window-dots span:nth-child(1) { background: #ff5f57; }
.window-dots span:nth-child(2) { background: #ffbd2e; }
.window-dots span:nth-child(3) { background: #28ca42; }
.window-title { font-size: 0.82rem; color: var(--text-muted); font-weight: 500; }
.window-controls { display: flex; gap: 8px; }
.win-btn { color: var(--text-dim); font-size: 0.85rem; cursor: default; }
.win-btn.close { color: #ff5f57; }
.window-body { padding: 24px; display: flex; flex-direction: column; gap: 18px; }
.demo-row { display: flex; align-items: center; gap: 16px; }
.demo-label { width: 140px; flex-shrink: 0; font-size: 0.85rem; color: var(--text-muted); font-weight: 500; }
.demo-controls { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }

/* Demo Controls */
.cs-button {
    padding: 8px 20px; border: 1px solid var(--border-light); border-radius: 6px; font-size: 0.85rem;
    cursor: pointer; transition: var(--transition); font-family: inherit;
    background: var(--bg-white); color: var(--text-secondary); font-weight: 500;
}
.cs-button.primary { background: var(--primary); color: #fff; border-color: var(--primary); }
.cs-button.primary:hover { background: var(--primary-dark); box-shadow: var(--shadow-blue); }
.cs-button:hover { border-color: var(--primary-light); color: var(--primary); }
.cs-button.danger { background: #fef2f2; color: #dc2626; border-color: #fecaca; }
.cs-button.danger:hover { background: #fee2e2; border-color: #fca5a5; }

.cs-input, .cs-select {
    padding: 8px 14px; background: var(--bg-white); border: 1px solid var(--border-light);
    border-radius: 6px; color: var(--text); font-size: 0.85rem; font-family: inherit;
    outline: none; transition: var(--transition); min-width: 200px;
}
.cs-input:focus, .cs-select:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.12); }
.cs-select { cursor: pointer; }
.cs-select option { background: var(--bg-white); color: var(--text); }

.cs-checkbox, .cs-radio { display: flex; align-items: center; gap: 6px; font-size: 0.85rem; cursor: pointer; color: var(--text-secondary); }
.cs-checkbox input, .cs-radio input { accent-color: var(--primary); width: 16px; height: 16px; cursor: pointer; }

.cs-progress { width: 200px; height: 6px; background: #e2e8f0; border-radius: 3px; overflow: hidden; }
.cs-progress-bar { height: 100%; background: linear-gradient(90deg, var(--primary), var(--accent)); border-radius: 3px; }

.cs-switch { position: relative; display: inline-block; width: 44px; height: 22px; cursor: pointer; }
.cs-switch input { opacity: 0; width: 0; height: 0; }
.switch-slider {
    position: absolute; inset: 0; background: #cbd5e1; border-radius: 22px;
    transition: var(--transition); cursor: pointer;
}
.switch-slider::before {
    content: ''; position: absolute; height: 16px; width: 16px; left: 3px; bottom: 3px;
    background: #fff; border-radius: 50%; transition: var(--transition); box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}
.cs-switch input:checked + .switch-slider { background: var(--primary); }
.cs-switch input:checked + .switch-slider::before { transform: translateX(22px); }

/* ---------- Start / Steps ---------- */
.start { padding: 80px 0 120px; }
.steps { display: flex; align-items: flex-start; justify-content: center; gap: 0; max-width: 900px; margin: 0 auto 48px; }
.step-item { flex: 1; text-align: center; position: relative; padding: 0 16px; }
.step-number {
    font-size: 3.5rem; font-weight: 900; color: rgba(37,99,235,0.06);
    position: absolute; top: -20px; left: 50%; transform: translateX(-50%);
    line-height: 1; z-index: 0; pointer-events: none;
}
.step-icon {
    width: 64px; height: 64px; border-radius: 50%; background: var(--bg-white);
    border: 2px solid var(--border-light); display: flex; align-items: center;
    justify-content: center; margin: 0 auto 20px; position: relative; z-index: 1;
    color: var(--primary); transition: var(--transition); box-shadow: var(--shadow-sm);
}
.step-item:hover .step-icon { border-color: var(--primary); background: var(--primary-bg); }
.step-item h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 10px; color: var(--text); }
.step-item p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.7; }
.step-connector { display: flex; align-items: center; padding-top: 32px; flex-shrink: 0; }
.step-connector span { width: 40px; height: 2px; background: var(--border); display: block; position: relative; }
.step-connector span::after {
    content: ''; position: absolute; right: -3px; top: -3px; width: 8px; height: 8px;
    border-top: 2px solid var(--border-light); border-right: 2px solid var(--border-light); transform: rotate(45deg);
}

/* Code Block */
.code-block {
    max-width: 720px; margin: 0 auto; background: var(--bg-code); border-radius: var(--radius); overflow: hidden;
    box-shadow: var(--shadow-lg);
}
.code-header {
    display: flex; align-items: center; gap: 16px;
    padding: 12px 20px; background: rgba(0,0,0,0.2); border-bottom: 1px solid rgba(255,255,255,0.06);
}
.code-dots { display: flex; gap: 7px; }
.code-dots span { width: 11px; height: 11px; border-radius: 50%; }
.code-dots span:nth-child(1) { background: #ff5f57; }
.code-dots span:nth-child(2) { background: #ffbd2e; }
.code-dots span:nth-child(3) { background: #28ca42; }
.code-title { font-size: 0.82rem; color: var(--text-dim); font-family: "Consolas", "Courier New", monospace; }
.code-body { padding: 20px 24px; overflow-x: auto; }
.code-body code {
    font-family: "Consolas", "Courier New", monospace; font-size: 0.85rem; line-height: 1.8; color: #e2e8f0;
}
.code-comment { color: #64748b; font-style: italic; }
.code-keyword { color: #a78bfa; }
.code-type { color: #60a5fa; }

/* ---------- License ---------- */
.license { padding: 120px 0; background: var(--bg-white); }
.license-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px; }
.license-card {
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius); padding: 36px 28px; text-align: center; transition: var(--transition);
    box-shadow: var(--shadow-sm);
}
.license-card:hover { border-color: var(--border-light); transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.license-icon { width: 56px; height: 56px; border-radius: 50%; background: var(--primary-bg); display: flex; align-items: center; justify-content: center; margin: 0 auto 20px; color: var(--primary); }
.license-card h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 10px; color: var(--text); }
.license-card p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.7; }

/* ---------- CTA ---------- */
.cta { padding: 80px 0 120px; }
.cta-card {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: var(--radius-lg); padding: 72px 48px; text-align: center; position: relative; overflow: hidden;
    box-shadow: 0 20px 60px rgba(37,99,235,0.2);
}
.cta-card::before { content: ''; position: absolute; top: -100px; right: -80px; width: 300px; height: 300px; border-radius: 50%; background: rgba(255,255,255,0.1); }
.cta-card::after { content: ''; position: absolute; bottom: -60px; left: -40px; width: 200px; height: 200px; border-radius: 50%; background: rgba(255,255,255,0.06); }
.cta-card h2 { font-size: clamp(1.6rem, 3.5vw, 2.5rem); font-weight: 900; margin-bottom: 12px; color: #fff; position: relative; z-index: 1; }
.cta-card p { font-size: 1.05rem; color: rgba(255,255,255,0.8); margin-bottom: 36px; position: relative; z-index: 1; }
.cta-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; position: relative; z-index: 1; }

/* ---------- Footer ---------- */
.footer { padding: 64px 0 32px; background: var(--bg-white); border-top: 1px solid var(--border); }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 48px; }
.footer-brand .logo { margin-bottom: 12px; }
.footer-brand p { font-size: 0.85rem; color: var(--text-muted); }
.footer-links h4 { font-size: 0.9rem; font-weight: 600; color: var(--text); margin-bottom: 16px; }
.footer-links ul { display: flex; flex-direction: column; gap: 10px; }
.footer-links a { font-size: 0.85rem; color: var(--text-muted); }
.footer-links a:hover { color: var(--primary); }
.footer-bottom { text-align: center; padding-top: 24px; border-top: 1px solid var(--border); }
.footer-bottom p { font-size: 0.82rem; color: var(--text-dim); }

/* ---------- Back to Top ---------- */
.back-to-top {
    position: fixed; bottom: 32px; right: 32px; z-index: 999;
    width: 44px; height: 44px; border-radius: 50%;
    background: var(--bg-white); border: 1px solid var(--border-light);
    color: var(--text-muted); cursor: pointer; display: flex;
    align-items: center; justify-content: center;
    opacity: 0; visibility: hidden; transition: var(--transition); box-shadow: var(--shadow);
}
.back-to-top.visible { opacity: 1; visibility: visible; }
.back-to-top:hover { background: var(--primary); color: #fff; border-color: var(--primary); transform: translateY(-2px); }

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
    .nav-links { display: none; }
    .mobile-toggle { display: flex; }
    .hero-stats { gap: 32px; }
    .stat-number { font-size: 2rem; }
}
@media (max-width: 768px) {
    .container { padding: 0 16px; }
    .navbar { padding: 12px 0; }
    .navbar.scrolled { background: rgba(255,255,255,0.95); }
    .logo { font-size: 1.05rem; gap: 8px; }
    .logo svg { width: 28px; height: 28px; }
    .logo-img { width: 28px; height: 28px; }
    .nav-actions .btn { padding: 8px 16px; font-size: 0.82rem; }

    .nav-links {
        display: flex; flex-direction: column; position: fixed;
        top: 0; right: 0; width: 75%; max-width: 320px;
        height: 100vh; height: 100dvh; background: var(--bg-white);
        border-left: 1px solid var(--border); padding: 80px 28px 32px;
        gap: 4px; transform: translateX(100%);
        transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
        z-index: 1001; overflow-y: auto; box-shadow: -10px 0 40px rgba(0,0,0,0.1);
    }
    .nav-links.open { transform: translateX(0); }
    .nav-links li { width: 100%; }
    .nav-links a { display: block; font-size: 1rem; padding: 14px 0; border-bottom: 1px solid var(--border); color: var(--text-secondary); }
    .nav-links a::after { display: none; }
    .nav-overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.3); z-index: 1000; opacity: 0; transition: opacity 0.3s; }
    .nav-overlay.visible { display: block; opacity: 1; }
    .mobile-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
    .mobile-toggle.active span:nth-child(2) { opacity: 0; }
    .mobile-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

    .hero { min-height: 100vh; min-height: 100dvh; padding: 100px 0 60px; }
    .hero-badge { font-size: 0.78rem; padding: 5px 14px; margin-bottom: 24px; }
    .hero-title { font-size: clamp(2rem, 9vw, 3rem); margin-bottom: 16px; }
    .hero-desc { font-size: 1rem; margin-bottom: 32px; }
    .hero-buttons { flex-direction: column; align-items: stretch; gap: 12px; margin-bottom: 48px; }
    .hero-buttons .btn { justify-content: center; }
    .hero-stats { gap: 20px; flex-wrap: wrap; }
    .stat-divider { display: none; }
    .stat-number { font-size: 1.6rem; }
    .stat-suffix { font-size: 0.9rem; }
    .stat-label { font-size: 0.72rem; }
    .hero-scroll { display: none; }

    .section-header { margin-bottom: 40px; }
    .section-tag { font-size: 0.72rem; padding: 5px 14px; }
    .section-title { font-size: clamp(1.4rem, 5vw, 2rem); }
    .section-desc { font-size: 0.92rem; }

    .features { padding: 64px 0; }
    .features-grid { grid-template-columns: 1fr; gap: 16px; }
    .feature-card { padding: 28px 22px; }
    .feature-icon { width: 48px; height: 48px; margin-bottom: 16px; }

    .preview { padding: 48px 0 80px; }
    .window-body { padding: 16px; gap: 14px; }
    .demo-row { flex-direction: column; align-items: flex-start; gap: 8px; }
    .demo-label { width: auto; }
    .demo-controls { flex-wrap: wrap; }
    .cs-input, .cs-select { min-width: 0; width: 100%; }
    .cs-progress { width: 100%; }

    .start { padding: 48px 0 80px; }
    .steps { flex-direction: column; gap: 32px; }
    .step-item { padding: 0; }
    .step-connector { padding-top: 0; justify-content: center; }
    .step-connector span { width: 2px; height: 28px; }
    .step-connector span::after { right: -3px; top: auto; bottom: -4px; transform: rotate(135deg); }
    .code-block { max-width: 100%; }
    .code-body { padding: 16px; }
    .code-body code { font-size: 0.76rem; }

    .license { padding: 64px 0; }
    .license-grid { grid-template-columns: 1fr; gap: 16px; }
    .license-card { padding: 28px 22px; }

    .cta { padding: 48px 0 80px; }
    .cta-card { padding: 48px 20px; border-radius: 16px; }
    .cta-card h2 { font-size: 1.4rem; }
    .cta-card p { font-size: 0.92rem; margin-bottom: 28px; }
    .cta-buttons { flex-direction: column; }

    .footer { padding: 48px 0 24px; }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 28px; margin-bottom: 32px; }
    .footer-brand { grid-column: 1 / -1; text-align: center; }
    .footer-brand .logo { justify-content: center; }
    .footer-links { text-align: center; }
    .footer-bottom p { font-size: 0.76rem; }

    .back-to-top { bottom: 20px; right: 16px; width: 40px; height: 40px; }
}
@media (max-width: 480px) {
    .container { padding: 0 14px; }
    .hero { padding: 90px 0 48px; }
    .hero-title { font-size: clamp(1.8rem, 10vw, 2.5rem); }
    .hero-desc { font-size: 0.92rem; }
    .hero-stats { gap: 16px; }
    .stat-number { font-size: 1.4rem; }
    .stat-suffix { font-size: 0.8rem; }
    .feature-card { padding: 24px 18px; }
    .cta-card { padding: 36px 16px; }
    .cta-card h2 { font-size: 1.2rem; }
    .footer-grid { grid-template-columns: 1fr; gap: 24px; }
}
@media (max-width: 360px) {
    .hero-title { font-size: 1.6rem; }
    .stat-number { font-size: 1.2rem; }
    .nav-actions .btn { padding: 6px 12px; font-size: 0.76rem; }
    .logo span { font-size: 0.95rem; }
}
@media (hover: none) and (pointer: coarse) {
    .feature-card:hover, .license-card:hover { transform: none; box-shadow: var(--shadow-sm); }
    .feature-card:hover::before { opacity: 0; }
}
@supports (padding: env(safe-area-inset-bottom)) {
    .footer-bottom { padding-bottom: env(safe-area-inset-bottom); }
    .back-to-top { bottom: calc(20px + env(safe-area-inset-bottom)); }
}