:root {
    --main: #131415;
    --main-light: #1e1f21;
    --main-lighter: #2a2b2d;
    --text: #dcddde;
    --text-muted: #72767d;
    --accent: #5865F2;
    --accent-hover: #4752C4;
    --border: #2f3136;
    --success: #3ba55d;
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Roboto', sans-serif; }
html, body { width: 100%; height: 100%; background: var(--main); color: var(--text); }

.appHeader {
    background: var(--main);
    border-bottom: 1px solid var(--border);
    padding: 0 20px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
}

.brand { font-size: 1.1rem; font-weight: 500; color: var(--text); cursor: pointer; display: flex; align-items: center; gap: 10px; }
.brand::before { content: "D"; background: var(--accent); width: 32px; height: 32px; border-radius: 8px; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 1.2rem; }
.brand small { color: var(--text-muted); font-weight: 400; }

.btn { background: var(--main-lighter); color: var(--text); border: none; padding: 8px 16px; border-radius: 4px; cursor: pointer; font-size: 0.9rem; font-weight: 500; transition: all 0.2s; text-decoration: none; display: inline-flex; align-items: center; gap: 8px; }
.btn:hover { background: var(--main-light); }
.btn.accent { background: var(--accent); }
.btn.accent:hover { background: var(--accent-hover); }
.btn.large { padding: 12px 24px; font-size: 1rem; }

.appWrap { display: flex; padding-top: 56px; min-height: 100vh; }
.panel { background: var(--main); border-right: 1px solid var(--border); display: flex; flex-direction: column; }
.panelHeader { padding: 16px; font-size: 0.85rem; font-weight: 500; text-transform: uppercase; color: var(--text-muted); letter-spacing: 0.5px; border-bottom: 1px solid var(--border); }
.panel.left { width: 280px; flex-shrink: 0; }

.downloadList { padding: 8px; }
.downloadItem { padding: 12px; margin-bottom: 4px; border-radius: 4px; cursor: pointer; transition: all 0.2s; display: flex; align-items: center; gap: 12px; }
.downloadItem:hover { background: var(--main-lighter); }
.downloadItem.active { background: var(--main-light); border-left: 3px solid var(--accent); }
.downloadItem.detected { border-left: 3px solid var(--success); }

.platformIcon { font-size: 1.5rem; }
.platformInfo { flex: 1; }
.platformName { font-weight: 500; color: var(--text); }
.platformVersion { font-size: 0.8rem; color: var(--text-muted); }

.badge { background: var(--success); color: #fff; font-size: 0.7rem; padding: 2px 8px; border-radius: 10px; font-weight: 500; }
.badge.secondary { background: var(--accent); }
.badge.coming-soon { background: var(--text-muted); }

.panel.center { flex: 1; border-right: none; padding: 24px; overflow-y: auto; }
.contentHeader { margin-bottom: 24px; }
.contentHeader h1 { font-size: 1.8rem; font-weight: 500; margin-bottom: 8px; }
.contentHeader p { color: var(--text-muted); }

.featuredBox { background: var(--main-light); border: 1px solid var(--border); border-radius: 8px; padding: 32px; margin-bottom: 24px; text-align: center; position: relative; }
.featuredBox.detected::before { content: "DETECTED: " attr(data-os); position: absolute; top: -1px; left: 50%; transform: translateX(-50%); background: var(--success); color: #fff; padding: 4px 16px; font-size: 0.7rem; font-weight: 700; letter-spacing: 0.5px; border-radius: 0 0 8px 8px; }
.featuredBox.selected::before { content: "SELECTED"; position: absolute; top: -1px; left: 50%; transform: translateX(-50%); background: var(--accent); color: #fff; padding: 4px 16px; font-size: 0.7rem; font-weight: 700; letter-spacing: 0.5px; border-radius: 0 0 8px 8px; }

.featuredIcon { font-size: 4rem; margin-bottom: 16px; }
.featuredTitle { font-size: 1.5rem; font-weight: 500; margin-bottom: 8px; }
.featuredVersion { color: var(--text-muted); margin-bottom: 24px; }
.featuredActions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

.allPlatforms { margin-top: 32px; }
.allPlatforms h3 { font-size: 1.1rem; font-weight: 500; margin-bottom: 16px; color: var(--text-muted); display: flex; align-items: center; gap: 8px; }
.allPlatforms h3::before { content: "📥"; }
.platformsGrid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; }
.platformCard { background: var(--main-light); border: 1px solid var(--border); border-radius: 8px; padding: 20px; text-align: center; cursor: pointer; transition: all 0.2s; }
.platformCard:hover { border-color: var(--accent); transform: translateY(-2px); }
.platformCard.active { border-color: var(--accent); background: hsl(from var(--accent) h s calc(l * 0.2)); }
.platformCard.detected { border-color: var(--success); }
.platformCard .cardIcon { font-size: 2.5rem; margin-bottom: 12px; }
.platformCard .cardName { font-weight: 500; margin-bottom: 4px; }
.platformCard .cardVersion { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 12px; }
.platformCard .cardBtn { display: inline-block; background: var(--main-lighter); color: var(--text); padding: 8px 16px; border-radius: 4px; text-decoration: none; font-size: 0.9rem; transition: all 0.2s; }
.platformCard:hover .cardBtn { background: var(--accent); }
.platformCard.coming-soon { opacity: 0.6; cursor: not-allowed; }
.platformCard.coming-soon:hover { border-color: var(--border); transform: none; }

.featuresSection { margin-top: 32px; }
.featuresSection h3 { font-size: 1.1rem; font-weight: 500; margin-bottom: 16px; color: var(--text-muted); }
.featuresList { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 12px; }
.featureItem { background: var(--main-light); border: 1px solid var(--border); border-radius: 6px; padding: 16px; display: flex; align-items: center; gap: 12px; }
.featureIcon { font-size: 1.5rem; }

.appFooter { text-align: center; padding: 24px; color: var(--text-muted); font-size: 0.85rem; border-top: 1px solid var(--border); margin-top: 32px; }

@media (max-width: 768px) { .panel.left { display: none; } .panel.center { padding: 16px; } .platformsGrid { grid-template-columns: 1fr; } }

::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--main-lighter); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--main-light); }