fix(ui): 投稿须知卡片浅色化、搜索按钮indigo化、添加按钮几何风格

- RequestForm 左侧投稿须知卡片：从 rgba(0,0,0,0.4) 黑透明改为 bg-secondary#f4f4f5 浅灰底+边+16px圆角，标题加粗深色
- 搜索输入框：从深色 input-bg 改为白底细灰边，indigo focus 环；搜索按钮从 blue 渐变胶囊升级为 indigo(#4f46e5→#6366f1) 渐变硬边12px+投影
- 联合投稿区域：section-label 改深字；添加按钮从 bg-tertiary+白字改为 浅灰底+深灰字 hover indigo 填充反白；标签 collaborator-tag 同步 indigo 淡底

app/components/Songs/RequestForm.vue

@@ -2934,10 +2934,11 @@ defineExpose({
 }
 
 .rules-section {
-  background: rgba(0, 0, 0, 0.4);
-  border-radius: 13px;
-  padding: 1.25rem;
-  flex: 0 0 35%; /* 稍微缩小规则区域占比 */
+  background: var(--bg-secondary, #f4f4f5);
+  border: 1px solid var(--border-secondary, #e4e4e7);
+  border-radius: 16px;
+  padding: 1.5rem 1.75rem;
+  flex: 0 0 35%;
   min-width: 300px;
   height: 100%;
   overflow-y: auto;
@@ -2945,24 +2946,24 @@ defineExpose({
 
 .section-title {
   font-family: 'MiSans', sans-serif;
-  font-weight: 400;
-  font-size: 15px;
-  letter-spacing: 0.04em;
-  color: var(--text-secondary);
-  margin-bottom: 0.75rem;
+  font-weight: 700;
+  font-size: 16px;
+  letter-spacing: 0.02em;
+  color: var(--text-primary, #09090b);
+  margin-bottom: 1rem;
 }
 
 .rules-content-desktop {
   font-family: 'MiSans', sans-serif;
   font-weight: 400;
   font-size: 15px;
-  line-height: 1.7;
-  letter-spacing: 0.04em;
-  color: var(--text-primary, #ffffff);
+  line-height: 1.75;
+  letter-spacing: 0.02em;
+  color: var(--text-primary, #18181b);
 }
 
 .rules-content-desktop p {
-  margin-bottom: 0.6rem;
+  margin-bottom: 0.7rem;
 }
 
 /* 移动端样式 */
@@ -3216,47 +3217,55 @@ defineExpose({
 }
 
 .search-input {
-  background: var(--input-bg, #040e15);
-  border: 1px solid var(--input-border, #242f38);
-  border-radius: 8px;
-  padding: 0.6rem 0.85rem;
+  background: var(--bg-primary, #ffffff);
+  border: 1px solid var(--border-secondary, #e4e4e7);
+  border-radius: 12px;
+  padding: 0.75rem 1rem;
   font-family: 'MiSans', sans-serif;
   font-weight: 600;
   font-size: 15px;
-  color: var(--input-text, rgba(255, 255, 255, 0.6));
+  color: var(--text-primary, #09090b);
   flex: 1;
-  min-width: 100px; /* 确保输入框不会缩到太小 */
+  min-width: 100px;
+  transition: all 0.2s ease;
+}
+
+.search-input::placeholder {
+  color: var(--text-tertiary, #a1a1aa);
 }
 
 .search-input:focus {
   outline: none;
-  border-color: #0b5afe;
+  border-color: var(--primary, #4f46e5);
+  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
 }
 
 .search-button {
-  background: linear-gradient(180deg, var(--bg-secondary, #0043f8) 0%, #0075f8 100%);
-  border: 1px solid rgba(255, 255, 255, 0.16);
-  border-radius: 8px;
-  padding: 0.75rem 1.5rem;
-  color: var(--text-primary, #ffffff);
+  background: linear-gradient(180deg, #4f46e5 0%, #6366f1 100%);
+  border: 1px solid rgba(79, 70, 229, 0.25);
+  border-radius: 12px;
+  padding: 0.8rem 1.75rem;
+  color: #ffffff;
   font-family: 'MiSans', sans-serif;
-  font-weight: 600;
+  font-weight: 700;
   font-size: 14px;
   cursor: pointer;
   white-space: nowrap;
   transition: all 0.3s ease;
-  flex-shrink: 0; /* 确保搜索按钮始终完整显示，不被重叠 */
+  flex-shrink: 0;
+  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.18);
 }
 
 .search-button:hover:not(:disabled) {
   transform: translateY(-2px);
-  box-shadow: 0 4px 12px rgba(0, 67, 248, 0.3);
+  box-shadow: 0 6px 16px rgba(79, 70, 229, 0.28);
 }
 
 .search-button:disabled {
   opacity: 0.5;
   cursor: not-allowed;
   transform: none;
+  box-shadow: 0 2px 6px rgba(79, 70, 229, 0.1);
 }
 
 /* 联合投稿人区域 */
@@ -3265,16 +3274,16 @@ defineExpose({
   align-items: center;
   gap: 1rem;
   flex: 1;
-  min-width: 200px; /* 增加最小宽度，防止在窄屏下与搜索框重叠 */
+  min-width: 200px;
 }
 
 .section-label {
   font-family: 'MiSans', sans-serif;
-  font-weight: 600;
+  font-weight: 700;
   font-size: 16px;
-  color: var(--text-primary, #ffffff);
+  color: var(--text-primary, #09090b);
   white-space: nowrap;
-  flex-shrink: 0; /* 防止标签被压缩 */
+  flex-shrink: 0;
 }
 
 .collaborators-list {
@@ -3288,45 +3297,52 @@ defineExpose({
   display: flex;
   align-items: center;
   gap: 0.5rem;
-  background: rgba(11, 90, 254, 0.1);
-  border: 1px solid rgba(11, 90, 254, 0.2);
-  border-radius: 6px;
-  padding: 0.25rem 0.5rem;
-  font-size: 14px;
-  color: var(--text-primary, #ffffff);
+  background: rgba(79, 70, 229, 0.08);
+  border: 1px solid rgba(79, 70, 229, 0.2);
+  border-radius: 10px;
+  padding: 0.3rem 0.6rem;
+  font-size: 13px;
+  color: var(--primary, #4f46e5);
+  font-weight: 600;
 }
 
 .remove-collaborator {
   background: none;
   border: none;
-  color: var(--text-secondary);
+  color: var(--primary, #4f46e5);
   cursor: pointer;
   display: flex;
   align-items: center;
   padding: 0;
+  opacity: 0.7;
+  transition: opacity 0.2s;
 }
 
 .remove-collaborator:hover {
-  color: var(--text-primary, #ffffff);
+  opacity: 1;
+  color: #4338ca;
 }
 
 .add-collaborator-btn {
   display: flex;
   align-items: center;
-  gap: 0.25rem;
-  background: var(--bg-tertiary);
-  border: 1px solid rgba(255, 255, 255, 0.1);
-  border-radius: 6px;
-  padding: 0.25rem 0.75rem;
+  gap: 0.3rem;
+  background: var(--bg-secondary, #f4f4f5);
+  border: 1px solid var(--border-secondary, #e4e4e7);
+  border-radius: 10px;
+  padding: 0.45rem 0.9rem;
   font-size: 13px;
-  color: rgba(255, 255, 255, 0.8);
+  font-weight: 600;
+  color: var(--text-secondary, #52525b);
   cursor: pointer;
-  transition: all 0.2s;
+  transition: all 0.2s ease;
 }
 
 .add-collaborator-btn:hover {
-  background: rgba(255, 255, 255, 0.1);
-  color: var(--text-primary, #ffffff);
+  background: var(--primary, #4f46e5);
+  color: #ffffff;
+  border-color: var(--primary, #4f46e5);
+  box-shadow: 0 4px 10px rgba(79, 70, 229, 0.18);
 }
 
 /* 自定义复选框样式 */