:root {
            --bg-color: #000000;
            --text-primary: #f5f5f7;
            --text-secondary: #a1a1a6;
            --accent-color: #0071e3;
            --accent-hover: #0077ed;
            --card-bg: #111111;
            --border-color: rgba(255, 255, 255, 0.15);
            --font-family: 'Inter', 'SF Pro Display', 'Helvetica Neue', 'Helvetica', 'Arial', sans-serif;
        }
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body { font-family: var(--font-family); background-color: var(--bg-color); color: var(--text-primary); -webkit-font-smoothing: antialiased; }
        .background-container { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; z-index: -1; background-color: var(--bg-color); }
        .background-image { position: absolute; top: 0; left: 0; width: 100%; height: 100%; background-size: cover; background-position: center; opacity: 0; filter: blur(8px) brightness(0.7); transform: scale(1.05); transition: opacity 1.5s cubic-bezier(0.4, 0, 0.2, 1), transform 1.5s cubic-bezier(0.4, 0, 0.2, 1); }
        .background-image.active { opacity: 0.5; transform: scale(1); }
        .main-header { position: sticky; top: 0; z-index: 100; background-color: rgba(0, 0, 0, 0.7); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); border-bottom: 1px solid var(--border-color); }
        .nav-container { display: flex; justify-content: space-between; align-items: center; max-width: 1100px; margin: 0 auto; padding: 1rem 2rem; }
        .nav-title { font-size: 1.2rem; font-weight: 600; text-decoration: none; color: inherit; display: flex; align-items: center; }
        .nav-logo { height: 28px; margin-right: 12px; }
        .nav-title span { font-weight: 400; opacity: 0.7; }
        .nav-links a { color: var(--text-secondary); text-decoration: none; margin-left: 2rem; font-weight: 500; transition: color 0.3s ease; }
        .nav-links a:hover { color: var(--text-primary); }
        .nav-links a.active { color: var(--accent-color); font-weight: 600; }
        footer { padding: 4rem 2rem; text-align: center; color: var(--text-secondary); font-size: 0.9rem; }
        .download-container { display: flex; justify-content: center; align-items: center; min-height: calc(100vh - 120px); padding: 4rem 1rem; }
        .download-panel { background: var(--card-bg); border: 1px solid var(--border-color); border-radius: 24px; padding: 3rem; width: 100%; max-width: 600px; text-align: center; opacity: 0; transform: translateY(20px); animation: fadeInPanel 1s forwards ease-out; animation-delay: 0.2s; }
        @keyframes fadeInPanel { to { opacity: 1; transform: translateY(0); } }
        .panel-title { font-size: 2.5rem; font-weight: 700; margin-bottom: 1rem; }
        .panel-subtitle { font-size: 1.1rem; color: var(--text-secondary); margin-bottom: 2.5rem; }
        .controls { display: flex; flex-direction: column; gap: 1.5rem; margin-bottom: 2rem; }
        .custom-select { position: relative; width: 100%; }
        select { appearance: none; -webkit-appearance: none; background-color: rgba(255, 255, 255, 0.05); border: 1px solid var(--border-color); padding: 1rem 3rem 1rem 1.5rem; font-size: 1rem; color: var(--text-primary); border-radius: 12px; cursor: pointer; width: 100%; transition: all 0.3s; font-family: inherit; font-weight: 500; }
        select:hover { border-color: var(--accent-color); }
        .custom-select::after { content: '\f078'; font-family: "Font Awesome 6 Free"; font-weight: 900; position: absolute; top: 50%; right: 1.5rem; transform: translateY(-50%); pointer-events: none; color: var(--text-secondary); transition: color 0.3s; }
        .custom-select:hover::after { color: var(--accent-color); }
        .download-button { display: inline-flex; align-items: center; justify-content: center; gap: 10px; width: 100%; padding: 1rem 2rem; background: var(--accent-color); border: none; border-radius: 12px; text-decoration: none; color: #fff; font-weight: 600; font-size: 1rem; user-select: none; transition: background-color 0.3s, transform 0.2s, opacity 0.3s; }
        .download-button:hover:not(.disabled) { background: var(--accent-hover); transform: scale(1.02); }
        .download-button.disabled { opacity: 0.4; pointer-events: none; background: #333; }
        .version-info { color: var(--text-secondary); margin-top: 1.5rem; min-height: 1.2rem; }
        #version-display { font-weight: 700; color: var(--text-primary); }
        #post-download-content { display: none; text-align: left; }
        #post-download-content h3 { text-align: center; font-size: 1.8rem; font-weight: 600; color: #4cd964; margin-bottom: 0.5rem; }
        #post-download-content .instructions-intro { text-align: center; color: var(--text-secondary); margin-bottom: 2.5rem; }
        .steps-list { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 1.5rem; }
        .step { display: flex; align-items: flex-start; gap: 1rem; }
        .step-number { background-color: rgba(255, 255, 255, 0.1); color: var(--text-secondary); font-weight: 700; font-size: 0.9rem; width: 32px; height: 32px; border-radius: 50%; display: grid; place-items: center; flex-shrink: 0; border: 1px solid var(--border-color); }
        .step-content h4 { font-weight: 600; font-size: 1.1rem; color: var(--text-primary); margin: 0.2rem 0 0.2rem 0; }
        .step-content p { color: var(--text-secondary); font-size: 1rem; line-height: 1.5; margin: 0; }
        .step-content code { background-color: rgba(255, 255, 255, 0.1); padding: 0.2em 0.5em; border-radius: 6px; font-family: 'SF Mono', 'Menlo', 'monospace'; }
        .step.critical .step-number { background-color: #ffb400; border-color: #ffb400; color: #000; }
        .step.critical h4 { color: #ffb400; }
        .fade-in-final { animation: fadeInFinal 0.8s forwards ease-out; }
        @keyframes fadeInFinal { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
        iframe#version-frame { display: none; }
        @media (max-width: 768px) {
            .nav-container { padding: 1rem; }
            .nav-links { display: none; }
            .download-container { padding: 2rem 1rem; align-items: flex-start; }
            .download-panel { padding: 2rem; }
            .panel-title { font-size: 2rem; }
        }