*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #fff; --bg-muted: #fff; --border: #e2e2e2;
  --fg: #0a0a0a; --fg-muted: #555; --fg-faint: #999;
  --card-bg: #fff;
  --t: background .3s, color .3s, border-color .3s;
}
[data-theme="dark"] {
  --bg: #0c0c0c; --bg-muted: #181818; --border: #2c2c2c;
  --fg: #efefef; --fg-muted: #aaa; --fg-faint: #666; --card-bg: #141414;
}

html { scroll-behavior: smooth; }
body { font-family: 'Inter', sans-serif; background: var(--bg); color: var(--fg); font-size: 15px; line-height: 1.6; overflow-x: hidden; transition: var(--t); }
a { text-decoration: none; color: inherit; }

/* TOPBAR */
.topbar { display: flex; align-items: center; justify-content: space-between; padding: 18px 52px; position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,.55); backdrop-filter: blur(18px) saturate(180%); -webkit-backdrop-filter: blur(18px) saturate(180%); border-bottom: 1px solid rgba(0,0,0,.07); transition: var(--t); }
[data-theme="dark"] .topbar { background: rgba(12,12,12,.6); border-bottom-color: rgba(255,255,255,.07); }
.logo { font-size: 15px; font-weight: 800; letter-spacing: -.01em; color: var(--fg); font-style: italic; }
.logo b { font-style: normal; font-weight: 400; color: var(--fg-faint); }
.topnav { display: flex; gap: 32px; align-items: center; }
.topnav a { display: flex; flex-direction: column; gap: 3px; color: var(--fg); transition: opacity .15s; }
.topnav a:hover { opacity: .6; }
.topnav-title { font-size: 13px; font-weight: 700; display: flex; align-items: center; gap: 5px; }
.topnav-title::after { content: '↗'; font-size: 11px; opacity: .5; }
.topnav-desc { font-size: 11px; color: var(--fg-faint); max-width: 140px; line-height: 1.35; }
.topbar-email { font-size: 12px; color: var(--fg-faint); }
.theme-btn { display: flex; align-items: center; gap: 7px; padding: 7px 10px; border-radius: 100px; border: none; background: transparent; color: var(--fg); font: 600 12px/1 'Inter', sans-serif; cursor: pointer; transition: var(--t); }
.theme-btn:hover { opacity: .7; }
.track { width: 30px; height: 17px; border-radius: 100px; background: var(--border); position: relative; transition: background .3s; }
[data-theme="dark"] .track { background: var(--fg); }
.thumb { position: absolute; top: 2.5px; left: 2.5px; width: 12px; height: 12px; border-radius: 50%; background: var(--fg-faint); transition: transform .3s, background .3s; }
[data-theme="dark"] .thumb { transform: translateX(13px); background: var(--bg); }

/* BACK BREADCRUMB */
.breadcrumb { padding: 16px 52px; border-bottom: 1px solid var(--border); font-size: 12px; color: var(--fg-faint); display: flex; align-items: center; gap: 8px; }
.breadcrumb a { color: var(--fg-faint); transition: color .15s; }
.breadcrumb a:hover { color: var(--fg); }
.breadcrumb span { opacity: .4; }

/* PRODUCT HERO */
.prod-hero { padding: 72px 52px 60px; border-bottom: 1px solid var(--border); display: grid; grid-template-columns: 1fr auto; gap: 40px; align-items: center; }
.prod-eyebrow { font-size: 10.5px; font-weight: 700; letter-spacing: .14em; text-transform: uppercase; color: var(--fg-faint); margin-bottom: 18px; }
.prod-h1 { font-size: clamp(36px, 5vw, 64px); font-weight: 900; letter-spacing: -.04em; line-height: 1.0; margin-bottom: 16px; }
.prod-tagline { font-size: 16px; color: var(--fg-muted); max-width: 560px; line-height: 1.7; }
.prod-meta { display: flex; flex-direction: column; align-items: flex-end; gap: 10px; }
.sbadge { font-size: 10px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; padding: 5px 14px; border-radius: 100px; }
.sbadge-ready  { background: #14532d; color: #4ade80; }
.sbadge-proto  { background: #1e3a5f; color: #7db8f7; }
.sbadge-idea   { background: var(--bg-muted); color: var(--fg-faint); border: 1px solid var(--border); }
[data-theme="light"] .sbadge-ready { background: #dcfce7; color: #16a34a; }
[data-theme="light"] .sbadge-proto { background: #e8f0fe; color: #1a56db; }
.prod-date { font-size: 11px; color: var(--fg-faint); }

/* LAYOUT */
.prod-layout { display: grid; grid-template-columns: 1fr 320px; gap: 64px; padding: 64px 52px; align-items: start; }

/* VIDEO */
.prod-video { width: 100%; aspect-ratio: 16/9; background: var(--bg-muted); border: 1px solid var(--border); border-radius: 4px; overflow: hidden; margin-bottom: 48px; }
.prod-video iframe { width: 100%; height: 100%; border: none; }

/* DOC SECTIONS */
.prod-section { margin-bottom: 56px; }
.prod-section-title { font-size: 11px; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; border-bottom: 1.5px solid var(--fg); padding-bottom: 12px; margin-bottom: 28px; }
.doc-block { margin-bottom: 28px; }
.doc-block h4 { font-size: 15px; font-weight: 700; margin-bottom: 10px; }
.doc-block p { font-size: 14px; color: var(--fg-muted); line-height: 1.8; }
.doc-block ul { padding-left: 20px; margin-top: 8px; display: flex; flex-direction: column; gap: 4px; }
.doc-block li { font-size: 14px; color: var(--fg-muted); line-height: 1.7; }

/* SIDEBAR */
.prod-sidebar { position: sticky; top: 88px; display: flex; flex-direction: column; gap: 20px; }
.sidebar-block { border: 1.5px solid var(--fg); padding: 24px; display: flex; flex-direction: column; gap: 14px; transition: var(--t); }
.sidebar-block:hover { background: var(--fg); color: var(--bg); }
.sidebar-block:hover .sidebar-label { color: rgba(255,255,255,.4); }
.sidebar-block:hover .stack-chip { border-color: rgba(255,255,255,.2); color: rgba(255,255,255,.7); }
.sidebar-block:hover .dl-meta { color: rgba(255,255,255,.4); }
.sidebar-block:hover .dl-btn { color: rgba(255,255,255,.7); }
.sidebar-label { font-size: 10.5px; font-weight: 700; letter-spacing: .12em; text-transform: uppercase; color: var(--fg-faint); }
.chips { display: flex; flex-wrap: wrap; gap: 7px; }
.stack-chip { font-size: 11.5px; font-weight: 600; padding: 5px 13px; border: 1.5px solid var(--border); border-radius: 100px; transition: var(--t); }
.dl-item { display: flex; align-items: center; justify-content: space-between; padding: 10px 0; border-bottom: 1px solid var(--border); }
.dl-item:last-child { border-bottom: none; padding-bottom: 0; }
.dl-name { font-size: 13px; font-weight: 600; }
.dl-meta { font-size: 11px; color: var(--fg-faint); margin-top: 2px; }
.dl-btn { font-size: 11px; font-weight: 700; display: flex; align-items: center; gap: 4px; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 13px 24px; border-radius: 100px; font: 600 13px/1 'Inter', sans-serif; cursor: pointer; border: 1.5px solid transparent; transition: all .15s; }
.btn-dark { background: var(--fg); color: var(--bg); border-color: var(--fg); }
.btn-dark:hover { opacity: .82; }
.btn-full { width: 100%; justify-content: center; }

/* FOOTER */
footer { background: var(--bg); border-top: 1px solid var(--border); padding: 28px 52px; display: flex; align-items: center; justify-content: space-between; transition: var(--t); }
.foot-links { display: flex; gap: 24px; }
.foot-links a { font-size: 11.5px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--fg-faint); transition: color .15s; }
.foot-links a:hover { color: var(--fg); }
.foot-copy { font-size: 12px; color: var(--fg-faint); }

/* RESPONSIVE */
@media (max-width: 860px) {
  .topbar { padding: 14px 20px; }
  .topbar-email, .topnav-desc { display: none; }
  .topnav { gap: 16px; }
  .breadcrumb { padding: 12px 20px; }
  .prod-hero { padding: 48px 20px 40px; grid-template-columns: 1fr; }
  .prod-meta { align-items: flex-start; }
  .prod-layout { grid-template-columns: 1fr; padding: 40px 20px; }
  .prod-sidebar { position: static; }
  footer { padding: 22px 20px; flex-direction: column; gap: 12px; text-align: center; }
}