added basic project page

src/components/ProjectCard.astro

@@ -0,0 +1,49 @@
+---
+interface Props {
+  name: string;
+  href?: string;
+}
+
+const { name, href } = Astro.props;
+---
+
+<style lang="scss">
+  @import "../styles/_var.scss";
+
+  a {
+    color: white;
+    &.project-external {
+      text-decoration: none;
+      &::after {
+        background-color: white;
+        width: 20px;
+        position: absolute;
+        right: 20px;
+        top: 20px;
+      }
+    }
+  }
+  .content {
+    padding: 20px;
+    margin: 20px;
+    max-width: 40vw;
+    transition: border-color 0.3s;
+    h2 {
+      font-size: 20px;
+    }
+    &:hover {
+      border-color: $link;
+    }
+  }
+  .no-hover {
+    &:hover {
+      border: 1px solid lighten($highlight, 12%);
+    }
+  }
+</style>
+
+<div class={href ? "content" : "content no-hover"}>
+  <a class="project-external" target={href ? "_blank" : ""} href={href}>
+    <h2>{name}</h2><slot />
+  </a>
+</div>