style(ui): 全站 Memphis 换肤为玻璃拟态+极光渐变

设计 token 与中央类名保持不变,重写视觉:磨砂玻璃卡片、
紫→青渐变按钮、柔光阴影、发丝边框;emoji 图标换 SVG;
登录/支付/公告弹窗改为随主题的玻璃卡片。

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

frontend/src/components/Logo.vue

@@ -2,7 +2,7 @@
 // Vivid mark: an open spectrum ring (lens/aperture) around a play triangle,
 // with a shutter dot closing the gap — image + video in one glyph.
 // Transparent background so it reads on both the dark and light shells.
-// Colors follow the memphis crayon palette (orange / pink / blue).
+// Colors follow the aurora palette (violet / pink / cyan).
 // Each instance gets unique gradient ids (useId) so multiple logos on one
 // page don't share/clobber defs.
 import { useId } from 'vue'
@@ -18,9 +18,9 @@ const gRing = `vring-${uid}`
        xmlns="http://www.w3.org/2000/svg" class="shrink-0">
     <defs>
       <linearGradient :id="gRing" x1="6" y1="6" x2="42" y2="42" gradientUnits="userSpaceOnUse">
-        <stop stop-color="#ec5b13" />
-        <stop offset="0.5" stop-color="#f472b6" />
-        <stop offset="1" stop-color="#38bdf8" />
+        <stop stop-color="#7c5cfc" />
+        <stop offset="0.5" stop-color="#e879f9" />
+        <stop offset="1" stop-color="#22d3ee" />
       </linearGradient>
     </defs>
 
@@ -29,10 +29,10 @@ const gRing = `vring-${uid}`
       <circle r="17.5" fill="none" :stroke="`url(#${gRing})`" stroke-width="4.4"
               stroke-linecap="round" stroke-dasharray="84 32" transform="rotate(-58)" />
       <!-- play triangle = image + video -->
-      <path d="M-3 -6.5 L8.5 0 L-3 6.5 Z" fill="#ec5b13" stroke="#111" stroke-width="1.4"
+      <path d="M-3 -6.5 L8.5 0 L-3 6.5 Z" fill="#7c5cfc" stroke="#111" stroke-width="1.4"
             stroke-linejoin="round" />
       <!-- shutter dot -->
-      <circle cx="13" cy="-13" r="4.2" fill="#fef08a" stroke="#111" stroke-width="1.6" />
+      <circle cx="13" cy="-13" r="4.2" fill="#22d3ee" stroke="#111" stroke-width="1.6" />
     </g>
   </svg>
 </template>