Interactive Comment Box

:root {
  --cb-border: rgba(255, 255, 255, 0.1);
  --cb-focus: #3b82f6;
  --cb-focus-glow: rgba(59, 130, 246, 0.2);
  --cb-text: #f8fafc;
  --cb-muted: #64748b;
  --cb-bg: rgba(255, 255, 255, 0.04);
  --cb-btn-cancel-hover: rgba(255, 255, 255, 0.06);
  --cb-body-bg: #0f1117;
}

body {
  background: var(--cb-body-bg);
  color: var(--cb-text);
  font-family: "Inter", system-ui, sans-serif;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 1rem;
}

.comment-box-widget {
  display: flex;
  gap: 1rem;
  max-width: 600px;
  width: 100%;
  margin: 0 auto;
  font-family: "Inter", system-ui, sans-serif;
}

.comment-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  overflow: hidden;
  flex-shrink: 0;
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  border: 2px solid rgba(255, 255, 255, 0.1);
}

.comment-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.comment-body {
  flex: 1;
  min-width: 0;
}

#comment-textarea {
  width: 100%;
  border: 1px solid var(--cb-border);
  border-radius: 12px;
  padding: 0.75rem 1rem;
  font-size: 0.9375rem;
  font-family: inherit;
  resize: none;
  min-height: 44px;
  max-height: 400px;
  outline: none;
  transition: all 0.2s ease;
  overflow: hidden;
  background: var(--cb-bg);
  color: var(--cb-text);
  backdrop-filter: blur(8px);
}

#comment-textarea::placeholder {
  color: var(--cb-muted);
}

#comment-textarea:focus {
  border-color: var(--cb-focus);
  box-shadow: 0 0 0 3px var(--cb-focus-glow);
  min-height: 100px;
  background: rgba(255, 255, 255, 0.06);
}

.comment-footer {
  display: none;
  align-items: center;
  justify-content: space-between;
  margin-top: 0.75rem;
  animation: fadeIn 0.3s ease;
}

#comment-textarea:focus + .comment-footer,
.comment-footer.active {
  display: flex;
}

.char-limit {
  font-size: 0.75rem;
  color: var(--cb-muted);
}

.comment-btns {
  display: flex;
  gap: 0.5rem;
}

.btn-cancel,
.btn-post {
  padding: 0.5rem 1rem;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}

.btn-cancel {
  background: transparent;
  color: var(--cb-muted);
  border: 1px solid var(--cb-border);
}

.btn-cancel:hover {
  background: var(--cb-btn-cancel-hover);
  color: var(--cb-text);
}

.btn-post {
  background: var(--cb-focus);
  color: white;
  box-shadow: 0 0 16px rgba(59, 130, 246, 0.3);
}

.btn-post:hover:not(:disabled) {
  opacity: 0.9;
  transform: translateY(-1px);
}

.btn-post:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  box-shadow: none;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(-5px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

const textarea = document.getElementById("comment-textarea");
const charCountEl = document.getElementById("char-count");
const postBtn = document.getElementById("post-comment");
const cancelBtn = document.getElementById("cancel-comment");
const footer = document.getElementById("comment-footer");

textarea.addEventListener("input", () => {
  // Auto-resize
  textarea.style.height = "auto";
  textarea.style.height = textarea.scrollHeight + "px";

  // Char count
  const length = textarea.value.length;
  charCountEl.textContent = length;

  // Enable/disable post button
  postBtn.disabled = length === 0;

  // Color indicator for limit
  if (length >= 260) {
    charCountEl.style.color = "#ef4444";
  } else {
    charCountEl.style.color = "";
  }
});

textarea.addEventListener("focus", () => {
  footer.classList.add("active");
});

cancelBtn.addEventListener("click", () => {
  textarea.value = "";
  textarea.style.height = "auto";
  footer.classList.remove("active");
  textarea.blur();
});

postBtn.addEventListener("click", () => {
  if (textarea.value.trim()) {
    const originalText = postBtn.textContent;
    postBtn.textContent = "Posting...";
    postBtn.disabled = true;

    setTimeout(() => {
      alert("Comment posted!");
      textarea.value = "";
      textarea.style.height = "auto";
      postBtn.textContent = originalText;
      footer.classList.remove("active");
      textarea.blur();
    }, 1000);
  }
});

<!doctype html>
<html lang="en">

<head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Comment Box</title>
    <link rel="preconnect" href="https://fonts.googleapis.com" />
    <link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap" />
    <link rel="stylesheet" href="style.css" />
</head>

<body>
    <div class="comment-box-widget">
        <div class="comment-avatar">
            <img src="https://images.unsplash.com/photo-1535713875002-d1d0cf377fde?w=100&h=100&fit=crop" alt="User" />
        </div>
        <div class="comment-body">
            <textarea id="comment-textarea" placeholder="Write a comment..." maxlength="280"></textarea>
            <div class="comment-footer" id="comment-footer">
                <span class="char-limit"><span id="char-count">0</span> / 280</span>
                <div class="comment-btns">
                    <button id="cancel-comment" class="btn-cancel">Cancel</button>
                    <button id="post-comment" class="btn-post" disabled>Post</button>
                </div>
            </div>
        </div>
    </div>

    <script src="script.js"></script>
</body>

</html>

import { useState } from "react";

type Comment = {
  id: number;
  user: string;
  avatar: string;
  color: string;
  text: string;
  time: string;
  likes: number;
};

const INITIAL: Comment[] = [
  {
    id: 1,
    user: "Sarah Chen",
    avatar: "SC",
    color: "#bc8cff",
    text: "This is exactly what I was looking for! Clean API design.",
    time: "2h ago",
    likes: 12,
  },
  {
    id: 2,
    user: "Alex Rivera",
    avatar: "AR",
    color: "#58a6ff",
    text: "Great implementation. One suggestion: add keyboard shortcut support.",
    time: "45m ago",
    likes: 7,
  },
];

function CommentItem({ comment, onLike }: { comment: Comment; onLike: () => void }) {
  const [liked, setLiked] = useState(false);

  return (
    <div className="flex gap-3">
      <div
        className="w-8 h-8 rounded-full flex items-center justify-center text-xs font-bold text-[#0d1117] flex-shrink-0"
        style={{ background: comment.color }}
      >
        {comment.avatar}
      </div>
      <div className="flex-1">
        <div className="bg-[#161b22] border border-[#30363d] rounded-xl px-4 py-3">
          <div className="flex items-baseline justify-between mb-1">
            <span className="text-[#e6edf3] font-semibold text-sm">{comment.user}</span>
            <span className="text-[#484f58] text-xs">{comment.time}</span>
          </div>
          <p className="text-[#8b949e] text-sm leading-relaxed">{comment.text}</p>
        </div>
        <div className="flex items-center gap-4 mt-1.5 ml-1">
          <button
            onClick={() => {
              setLiked((l) => !l);
              onLike();
            }}
            className={`text-xs transition-colors ${liked ? "text-[#ff6b6b]" : "text-[#484f58] hover:text-[#8b949e]"}`}
          >
            {liked ? "♥" : "♡"} {comment.likes + (liked ? 1 : 0)}
          </button>
          <button className="text-xs text-[#484f58] hover:text-[#8b949e] transition-colors">
            Reply
          </button>
        </div>
      </div>
    </div>
  );
}

export default function CommentBoxRC() {
  const [comments, setComments] = useState<Comment[]>(INITIAL);
  const [text, setText] = useState("");
  const [submitting, setSubmitting] = useState(false);

  function submit() {
    if (!text.trim()) return;
    setSubmitting(true);
    setTimeout(() => {
      setComments((prev) => [
        ...prev,
        {
          id: Date.now(),
          user: "You",
          avatar: "YO",
          color: "#7ee787",
          text: text.trim(),
          time: "just now",
          likes: 0,
        },
      ]);
      setText("");
      setSubmitting(false);
    }, 500);
  }

  return (
    <div className="min-h-screen bg-[#0d1117] flex justify-center p-6">
      <div className="w-full max-w-lg">
        <h2 className="text-[#e6edf3] font-bold text-lg mb-5">{comments.length} Comments</h2>

        <div className="space-y-4 mb-6">
          {comments.map((c) => (
            <CommentItem key={c.id} comment={c} onLike={() => {}} />
          ))}
        </div>

        <div className="flex gap-3">
          <div className="w-8 h-8 rounded-full bg-[#7ee787] flex items-center justify-center text-xs font-bold text-[#0d1117] flex-shrink-0 mt-0.5">
            YO
          </div>
          <div className="flex-1">
            <textarea
              value={text}
              onChange={(e) => setText(e.target.value)}
              onKeyDown={(e) => {
                if (e.key === "Enter" && (e.metaKey || e.ctrlKey)) submit();
              }}
              placeholder="Add a comment…"
              rows={3}
              className="w-full bg-[#161b22] border border-[#30363d] rounded-xl px-4 py-3 text-[#e6edf3] placeholder-[#484f58] text-sm resize-none focus:outline-none focus:border-[#58a6ff] transition-colors"
            />
            <div className="flex items-center justify-between mt-2">
              <span className="text-[11px] text-[#484f58]">⌘↵ to submit</span>
              <button
                onClick={submit}
                disabled={!text.trim() || submitting}
                className="px-4 py-1.5 bg-[#238636] border border-[#2ea043] text-white text-sm rounded-lg font-semibold disabled:opacity-40 hover:bg-[#2ea043] transition-colors"
              >
                {submitting ? "Posting…" : "Comment"}
              </button>
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}

<script setup>
import { ref } from "vue";

const comments = ref([
  {
    id: 1,
    user: "Sarah Chen",
    avatar: "SC",
    color: "#bc8cff",
    text: "This is exactly what I was looking for! Clean API design.",
    time: "2h ago",
    likes: 12,
  },
  {
    id: 2,
    user: "Alex Rivera",
    avatar: "AR",
    color: "#58a6ff",
    text: "Great implementation. One suggestion: add keyboard shortcut support.",
    time: "45m ago",
    likes: 7,
  },
]);
const text = ref("");
const submitting = ref(false);
const likedMap = ref({});

function toggleLike(id) {
  likedMap.value[id] = !likedMap.value[id];
}

function submit() {
  if (!text.value.trim()) return;
  submitting.value = true;
  setTimeout(() => {
    comments.value.push({
      id: Date.now(),
      user: "You",
      avatar: "YO",
      color: "#7ee787",
      text: text.value.trim(),
      time: "just now",
      likes: 0,
    });
    text.value = "";
    submitting.value = false;
  }, 500);
}

function handleKey(e) {
  if (e.key === "Enter" && (e.metaKey || e.ctrlKey)) submit();
}
</script>

<template>
  <div class="min-h-screen bg-[#0d1117] flex justify-center p-6">
    <div class="w-full max-w-lg">
      <h2 class="text-[#e6edf3] font-bold text-lg mb-5">{{ comments.length }} Comments</h2>

      <div class="space-y-4 mb-6">
        <div v-for="c in comments" :key="c.id" class="flex gap-3">
          <div
            class="w-8 h-8 rounded-full flex items-center justify-center text-xs font-bold text-[#0d1117] flex-shrink-0"
            :style="{ background: c.color }"
          >
            {{ c.avatar }}
          </div>
          <div class="flex-1">
            <div class="bg-[#161b22] border border-[#30363d] rounded-xl px-4 py-3">
              <div class="flex items-baseline justify-between mb-1">
                <span class="text-[#e6edf3] font-semibold text-sm">{{ c.user }}</span>
                <span class="text-[#484f58] text-xs">{{ c.time }}</span>
              </div>
              <p class="text-[#8b949e] text-sm leading-relaxed">{{ c.text }}</p>
            </div>
            <div class="flex items-center gap-4 mt-1.5 ml-1">
              <button
                @click="toggleLike(c.id)"
                class="text-xs transition-colors"
                :class="likedMap[c.id] ? 'text-[#ff6b6b]' : 'text-[#484f58] hover:text-[#8b949e]'"
              >
                {{ likedMap[c.id] ? '\u2665' : '\u2661' }} {{ c.likes + (likedMap[c.id] ? 1 : 0) }}
              </button>
              <button class="text-xs text-[#484f58] hover:text-[#8b949e] transition-colors">Reply</button>
            </div>
          </div>
        </div>
      </div>

      <div class="flex gap-3">
        <div class="w-8 h-8 rounded-full bg-[#7ee787] flex items-center justify-center text-xs font-bold text-[#0d1117] flex-shrink-0 mt-0.5">
          YO
        </div>
        <div class="flex-1">
          <textarea
            v-model="text"
            @keydown="handleKey"
            placeholder="Add a comment..."
            rows="3"
            class="w-full bg-[#161b22] border border-[#30363d] rounded-xl px-4 py-3 text-[#e6edf3] placeholder-[#484f58] text-sm resize-none focus:outline-none focus:border-[#58a6ff] transition-colors"
          ></textarea>
          <div class="flex items-center justify-between mt-2">
            <span class="text-[11px] text-[#484f58]">Cmd+Enter to submit</span>
            <button
              @click="submit"
              :disabled="!text.trim() || submitting"
              class="px-4 py-1.5 bg-[#238636] border border-[#2ea043] text-white text-sm rounded-lg font-semibold disabled:opacity-40 hover:bg-[#2ea043] transition-colors"
            >
              {{ submitting ? 'Posting...' : 'Comment' }}
            </button>
          </div>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
let comments = [
  {
    id: 1,
    user: "Sarah Chen",
    avatar: "SC",
    color: "#bc8cff",
    text: "This is exactly what I was looking for! Clean API design.",
    time: "2h ago",
    likes: 12,
  },
  {
    id: 2,
    user: "Alex Rivera",
    avatar: "AR",
    color: "#58a6ff",
    text: "Great implementation. One suggestion: add keyboard shortcut support.",
    time: "45m ago",
    likes: 7,
  },
];
let text = "";
let submitting = false;
let likedMap = {};

function toggleLike(id) {
  likedMap[id] = !likedMap[id];
  likedMap = likedMap;
}

function submit() {
  if (!text.trim()) return;
  submitting = true;
  setTimeout(() => {
    comments = [
      ...comments,
      {
        id: Date.now(),
        user: "You",
        avatar: "YO",
        color: "#7ee787",
        text: text.trim(),
        time: "just now",
        likes: 0,
      },
    ];
    text = "";
    submitting = false;
  }, 500);
}

function handleKey(e) {
  if (e.key === "Enter" && (e.metaKey || e.ctrlKey)) submit();
}
</script>

<div class="min-h-screen bg-[#0d1117] flex justify-center p-6">
  <div class="w-full max-w-lg">
    <h2 class="text-[#e6edf3] font-bold text-lg mb-5">{comments.length} Comments</h2>

    <div class="space-y-4 mb-6">
      {#each comments as c (c.id)}
        <div class="flex gap-3">
          <div
            class="w-8 h-8 rounded-full flex items-center justify-center text-xs font-bold text-[#0d1117] flex-shrink-0"
            style="background: {c.color}"
          >
            {c.avatar}
          </div>
          <div class="flex-1">
            <div class="bg-[#161b22] border border-[#30363d] rounded-xl px-4 py-3">
              <div class="flex items-baseline justify-between mb-1">
                <span class="text-[#e6edf3] font-semibold text-sm">{c.user}</span>
                <span class="text-[#484f58] text-xs">{c.time}</span>
              </div>
              <p class="text-[#8b949e] text-sm leading-relaxed">{c.text}</p>
            </div>
            <div class="flex items-center gap-4 mt-1.5 ml-1">
              <button
                on:click={() => toggleLike(c.id)}
                class="text-xs transition-colors"
                class:text-[#ff6b6b]={likedMap[c.id]}
                class:text-[#484f58]={!likedMap[c.id]}
              >
                {likedMap[c.id] ? '\u2665' : '\u2661'} {c.likes + (likedMap[c.id] ? 1 : 0)}
              </button>
              <button class="text-xs text-[#484f58] hover:text-[#8b949e] transition-colors">Reply</button>
            </div>
          </div>
        </div>
      {/each}
    </div>

    <div class="flex gap-3">
      <div class="w-8 h-8 rounded-full bg-[#7ee787] flex items-center justify-center text-xs font-bold text-[#0d1117] flex-shrink-0 mt-0.5">
        YO
      </div>
      <div class="flex-1">
        <textarea
          bind:value={text}
          on:keydown={handleKey}
          placeholder="Add a comment..."
          rows="3"
          class="w-full bg-[#161b22] border border-[#30363d] rounded-xl px-4 py-3 text-[#e6edf3] placeholder-[#484f58] text-sm resize-none focus:outline-none focus:border-[#58a6ff] transition-colors"
        ></textarea>
        <div class="flex items-center justify-between mt-2">
          <span class="text-[11px] text-[#484f58]">Cmd+Enter to submit</span>
          <button
            on:click={submit}
            disabled={!text.trim() || submitting}
            class="px-4 py-1.5 bg-[#238636] border border-[#2ea043] text-white text-sm rounded-lg font-semibold disabled:opacity-40 hover:bg-[#2ea043] transition-colors"
          >
            {submitting ? 'Posting...' : 'Comment'}
          </button>
        </div>
      </div>
    </div>
  </div>
</div>