Align guest try-without-account CTAs with teal theme.

Match homepage secondary CTA fill/text to the login guest button and include guest focus styles so try-without-account surfaces share the same mint treatment.

Co-authored-by: Cursor <cursoragent@cursor.com>

phd-advisor-frontend/src/styles/Login.css

@@ -513,6 +513,7 @@
 
 /* Focus and Accessibility */
 .submit-btn:focus-visible,
+.guest-continue-btn:focus-visible,
 .google-btn:focus-visible,
 .phone-btn:focus-visible,
 .forgot-password:focus-visible,

phd-advisor-frontend/src/styles/components.css

@@ -321,14 +321,14 @@
 }
 
 .cta-button-secondary {
-  background: transparent;
-  color: var(--text-primary, #0f172a);
+  background: var(--accent-soft, #ccfbf1);
+  color: var(--accent-primary, #0f766e);
   border: 2px solid var(--accent-primary, #0f766e);
   box-shadow: none;
 }
 
 .cta-button-secondary:hover {
-  background: var(--accent-soft, #ccfbf1);
+  background: var(--accent-muted, #99f6e4);
 }
 
 .cta-button:hover {