style(ui): tighten spacing and button styles

Author: CopperKoi

src/pages/CandidateDetail.jsx

@@ -347,7 +347,7 @@ export default function CandidateDetail() {
             </div>
             {showApplication && (
               <div className="card-body">
-                <div className="content-gap-lg" />
+                <div className="content-gap" />
                 <p><strong>姓名：</strong> {user.application.realName}</p>
                 <p><strong>手机号：</strong> {user.application.phone}</p>
                 <p><strong>性别：</strong> {user.application.gender === "male" ? "男" : "女"}</p>
@@ -371,7 +371,7 @@ export default function CandidateDetail() {
           </div>
           {showComments && (
             <>
-              <div className="content-gap-lg" />
+              <div className="content-gap" />
               {comments.length > 0 ? (
                 comments.map((comment, index) => (
                   <div key={comment.id}>

src/styles.css

@@ -677,6 +677,7 @@ button.link-button {
   padding: 0;
   box-shadow: none;
   font-weight: 600;
+  border: none;
 }
 
 .link-button {
@@ -708,6 +709,7 @@ button:disabled {
   appearance: none;
   -webkit-appearance: none;
   -moz-appearance: none;
+  color: #B3B7BD;
 }
 
 .row {