Сделать lightbox на всю высоту экрана с небольшими отступами

Панель занимает 100dvh минус 1rem сверху/снизу; QR растягивается
в оставшееся пространство.

roles/hysteria2/templates/export/global-index.html.j2

@@ -251,7 +251,7 @@
       display: flex;
       align-items: center;
       justify-content: center;
-      padding: 1.75rem 1rem;
+      padding: 1rem;
       box-sizing: border-box;
       background: rgba(8, 12, 18, 0.72);
       backdrop-filter: blur(10px);
@@ -268,16 +268,19 @@
     }
     .lightbox-panel {
       position: relative;
-      max-width: min(94vw, 832px);
-      max-height: calc(100dvh - 3.5rem);
-      width: 100%;
+      display: flex;
+      flex-direction: column;
+      width: min(94vw, 900px);
+      height: calc(100dvh - 2rem);
+      max-height: calc(100dvh - 2rem);
       padding: 1.25rem 1.25rem 1rem;
       background: var(--bg-card);
       border: 1px solid var(--border);
       border-radius: 18px;
       box-shadow: 0 24px 64px rgba(0, 0, 0, 0.45);
       text-align: center;
-      overflow: auto;
+      overflow: hidden;
+      box-sizing: border-box;
       transform: translateY(12px) scale(0.96);
       transition: transform 0.22s ease;
     }
@@ -286,11 +289,10 @@
     }
     .lightbox-panel img {
       display: block;
+      max-width: 100%;
+      max-height: 100%;
       width: auto;
       height: auto;
-      max-width: min(728px, 100%);
-      max-height: min(728px, calc(100dvh - 14rem));
-      margin: 0 auto;
       aspect-ratio: 1;
       object-fit: contain;
       background: #fff;
@@ -299,18 +301,28 @@
       box-sizing: border-box;
       image-rendering: pixelated;
     }
+    .lightbox-media {
+      flex: 1 1 auto;
+      min-height: 0;
+      display: flex;
+      align-items: center;
+      justify-content: center;
+    }
     .lightbox-caption {
+      flex-shrink: 0;
       margin-top: 0.85rem;
       font-size: 0.95rem;
       font-weight: 650;
       color: var(--text);
     }
     .lightbox-hint {
+      flex-shrink: 0;
       margin-top: 0.25rem;
       font-size: 0.75rem;
       color: var(--muted);
     }
     .lightbox-actions {
+      flex-shrink: 0;
       margin-top: 1rem;
       display: flex;
       justify-content: center;
@@ -499,7 +511,9 @@
   <div class="lightbox" id="lightbox" role="dialog" aria-modal="true" aria-hidden="true" aria-labelledby="lightbox-caption">
     <div class="lightbox-panel" role="document">
       <button type="button" class="lightbox-close" id="lightbox-close" aria-label="Закрыть">&times;</button>
-      <img id="lightbox-img" src="" alt="">
+      <div class="lightbox-media">
+        <img id="lightbox-img" src="" alt="">
+      </div>
       <p class="lightbox-caption" id="lightbox-caption"></p>
       <div class="lightbox-actions">
         <a class="lightbox-download" id="lightbox-download" href="#" download>