/* ============================================================
   Prototype Lab — site chrome (navigation + home hub).
   NOT app components — this is the portal shell around prototypes.
   Requires tokens.css.
   ============================================================ */

/* ---------- Sticky top navigation (every page) ---------- */
.topnav { position: sticky; top: 0; z-index: 100; display: flex; align-items: center; justify-content: space-between;
          padding: 12px 24px; background: rgba(255,255,255,.82); backdrop-filter: saturate(180%) blur(12px);
          border-bottom: 1px solid var(--gray-4); }
.topnav .brand { display: flex; align-items: center; gap: 8px; font-size: 16px; font-weight: 800; color: var(--black); text-decoration: none; }
.topnav .brand .dot { width: 22px; height: 22px; border-radius: 7px; background: var(--purple-gradient); display: inline-block; }
.topnav .links { display: flex; gap: 6px; }
.topnav .links a { font-size: 13px; font-weight: 700; color: var(--gray-10); text-decoration: none; padding: 8px 14px; border-radius: var(--radius-pill); transition: background .15s, color .15s; }
.topnav .links a:hover { background: var(--gray-2); color: var(--black); }
.topnav .links a.current { background: var(--violet-extralight); color: var(--violet-dark); }
.topnav .links a .back { font-weight: 800; }

/* ---------- Home hub ---------- */
.hub { max-width: 1080px; margin: 0 auto; padding: 44px 24px 90px; }
.hero h1 { font-size: 36px; font-weight: 800; letter-spacing: -.5px; }
.hero p { color: var(--gray-10); margin-top: 10px; font-size: 15px; max-width: 640px; line-height: 1.55; }

.hub h2.sect { font-size: 13px; font-weight: 800; text-transform: uppercase; letter-spacing: .7px; color: var(--gray-8); margin: 44px 0 4px; }
.hub h2.sect .count { color: var(--gray-6); }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(264px, 1fr)); gap: 22px; margin-top: 20px; }
.card { background: #fff; border: 1px solid var(--gray-4); border-radius: 18px; overflow: hidden; text-decoration: none; color: inherit;
        transition: transform .15s, box-shadow .15s; display: flex; flex-direction: column; }
.card:hover { transform: translateY(-4px); box-shadow: 0 18px 40px rgba(40,40,80,.12); }
.thumb { height: 196px; display: grid; place-items: center; }
.thumb.proto { background: var(--main-screen-gradient); }
.thumb.ds { background: #fff; border-bottom: 1px solid var(--gray-4); }
.mini { width: 116px; height: 168px; background: #fff; border-radius: 18px; box-shadow: 0 10px 24px rgba(0,0,0,.18); padding: 10px;
        display: flex; flex-direction: column; gap: 8px; }
.mini.flat { box-shadow: none; border: 1px solid var(--gray-4); }
.mini .bar { height: 8px; border-radius: 4px; background: var(--gray-2); }
.mini .pc { height: 56px; border-radius: 10px; background: var(--purple-gradient); }
.mini .pc.sm { height: 24px; background: var(--gray-2); }
.meta { padding: 16px 18px 18px; }
.meta h3 { font-size: 17px; font-weight: 700; }
.meta p { font-size: 13px; color: var(--gray-10); margin-top: 4px; line-height: 1.4; }
.tags { display: flex; gap: 6px; margin-top: 12px; flex-wrap: wrap; }
.tag { font-size: 11px; font-weight: 700; padding: 4px 10px; border-radius: var(--radius-pill); background: var(--violet-extralight); color: var(--violet-dark); }
.tag.live { background: var(--green-extralight); color: var(--green-dark); }
.tag.ds { background: var(--blue-extralight); color: var(--blue); }
.empty { border: 2px dashed var(--gray-4); border-radius: 18px; display: grid; place-items: center; min-height: 280px; }
.empty-inner { text-align: center; padding: 24px; max-width: 232px; }
.empty-plus { width: 44px; height: 44px; margin: 0 auto; border-radius: 50%; border: 2px dashed var(--gray-6);
              display: grid; place-items: center; font-size: 24px; font-weight: 700; color: var(--gray-8); }
.empty-inner h4 { font-size: 15px; font-weight: 700; color: var(--gray-10); margin: 12px 0 6px; }
.empty-inner p { font-size: 12px; color: var(--gray-8); line-height: 1.45; }