:root {
  --fb-blue: #4267b2;
  --bg: #e9ebee;
  --card: #ffffff;
  --text: #1d2129;
  --muted: #606770;
  --line: #d3d6db;
  --comment-bg: #f2f3f5;
  --danger: #b71c1c;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: radial-gradient(circle at 10% -20%, #f7f8fa 0%, var(--bg) 45%, #dde1e8 100%);
  color: var(--text);
  font-family: "Helvetica Neue", Helvetica, Arial, "Apple SD Gothic Neo", "Noto Sans KR", sans-serif;
}

.topbar {
  background: var(--fb-blue);
  border-bottom: 1px solid #29487d;
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 5;
}

.topbar-inner {
  max-width: 880px;
  margin: 0 auto;
  padding: 10px 16px;
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.logo {
  margin: 0;
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.2px;
}

.tagline {
  margin: 0;
  font-size: 0.88rem;
  opacity: 0.9;
}

.page {
  max-width: 880px;
  margin: 16px auto;
  padding: 0 16px 28px;
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 3px;
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.04);
}

.composer {
  padding: 14px;
}

.composer h2 {
  margin: 0 0 12px;
  font-size: 1rem;
  color: #4b4f56;
}

#post-form {
  display: grid;
  gap: 8px;
}

label {
  font-size: 0.82rem;
  color: var(--muted);
}

input,
textarea {
  width: 100%;
  border: 1px solid #ccd0d5;
  border-radius: 2px;
  padding: 9px 10px;
  font-size: 0.95rem;
  font-family: inherit;
}

textarea {
  resize: vertical;
}

button {
  justify-self: end;
  margin-top: 4px;
  border: 1px solid #365899;
  background: linear-gradient(#4f75c2, #4267b2);
  color: #fff;
  padding: 7px 14px;
  border-radius: 2px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
}

button:hover {
  filter: brightness(1.04);
}

.feed {
  display: grid;
  gap: 12px;
}

.loading {
  color: #4b4f56;
  font-size: 0.95rem;
  padding: 8px 4px;
}

.global-error {
  background: #ffe6e6;
  color: var(--danger);
  border: 1px solid #f5b6b6;
  border-radius: 3px;
  padding: 10px 12px;
  font-size: 0.92rem;
}

.hidden {
  display: none;
}

.post {
  overflow: hidden;
}

.post-main {
  padding: 12px 14px;
}

.post-head {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  align-items: baseline;
}

.post-author {
  margin: 0;
  font-size: 0.96rem;
  font-weight: 700;
  color: #385898;
}

.post-time {
  margin: 0;
  font-size: 0.78rem;
  color: var(--muted);
}

.post-message {
  margin: 8px 0 0;
  line-height: 1.45;
  white-space: pre-wrap;
}

.comments {
  border-top: 1px solid var(--line);
  background: #f6f7f8;
  padding: 10px 12px 12px;
}

.comment {
  background: var(--comment-bg);
  border-radius: 16px;
  padding: 8px 12px;
  margin-bottom: 8px;
}

.comment:last-child {
  margin-bottom: 10px;
}

.comment-author {
  margin: 0;
  color: #385898;
  font-size: 0.85rem;
  font-weight: 700;
}

.comment-message {
  margin: 2px 0 0;
  font-size: 0.9rem;
  line-height: 1.4;
  white-space: pre-wrap;
}

.comment-time {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 0.75rem;
}

.comment-form {
  display: grid;
  grid-template-columns: 120px 1fr auto;
  gap: 8px;
}

.comment-form button {
  margin: 0;
  align-self: center;
}

.empty-feed {
  padding: 24px 12px;
  text-align: center;
  color: var(--muted);
  border: 1px dashed #c6cad0;
  border-radius: 4px;
  background: #f5f6f7;
}

@media (max-width: 700px) {
  .topbar-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
  }

  .comment-form {
    grid-template-columns: 1fr;
  }

  .comment-form button {
    justify-self: end;
  }
}