* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #15202b;
  --surface: #192734;
  --border: #38444d;
  --text: #e1e8ed;
  --text-muted: #8899a6;
  --accent: #1da1f2;
  --accent-hover: #1a91da;
  --danger: #e0245e;
  --success: #17bf63;
  --retweet: #17bf63;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.5;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  max-width: 600px;
  margin: 0 auto;
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
  min-height: 100vh;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  background: rgba(21, 32, 43, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  z-index: 100;
}

.header h2 { font-size: 1.2rem; }

.nav-tabs {
  display: flex;
  border-bottom: 1px solid var(--border);
}

.nav-tab {
  flex: 1;
  text-align: center;
  padding: 14px;
  cursor: pointer;
  color: var(--text-muted);
  font-weight: 500;
  transition: all 0.2s;
  border-bottom: 2px solid transparent;
}

.nav-tab:hover { background: rgba(29,161,242,0.1); }
.nav-tab.active { color: var(--accent); border-bottom-color: var(--accent); }

/* Auth */
.auth-page {
  padding: 40px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.auth-page h1 {
  font-size: 2rem;
  color: var(--accent);
}

.auth-form {
  width: 100%;
  max-width: 350px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.auth-form input {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
  color: var(--text);
  font-size: 1rem;
  outline: none;
  transition: border-color 0.2s;
}

.auth-form input:focus { border-color: var(--accent); }

.btn {
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 9999px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.2s;
}

.btn:hover { background: var(--accent-hover); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-outline {
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--accent);
}

.btn-outline:hover { background: rgba(29,161,242,0.1); }

.btn-danger { background: var(--danger); }
.btn-danger:hover { background: #c9204f; }

.btn-sm { padding: 6px 14px; font-size: 0.8rem; }

.error-msg { color: var(--danger); font-size: 0.85rem; text-align: center; }
.toggle-link { color: var(--accent); font-size: 0.9rem; cursor: pointer; }

/* Compose */
.compose-box {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  gap: 12px;
}

.compose-box textarea {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text);
  font-size: 1.1rem;
  resize: none;
  outline: none;
  min-height: 60px;
  font-family: inherit;
}

.compose-box textarea::placeholder { color: var(--text-muted); }

.compose-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}

.char-count { font-size: 0.8rem; color: var(--text-muted); }
.char-count.warn { color: #ffad1f; }
.char-count.over { color: var(--danger); }

/* Tweet */
.tweet {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  gap: 12px;
  transition: background 0.15s;
  cursor: pointer;
}

.tweet:hover { background: rgba(255,255,255,0.03); }

.avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.2rem;
  color: white;
  flex-shrink: 0;
}

.avatar.small { width: 36px; height: 36px; font-size: 0.9rem; }

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

.tweet-header {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.tweet-name { font-weight: 700; }
.tweet-username { color: var(--text-muted); font-size: 0.9rem; }
.tweet-time { color: var(--text-muted); font-size: 0.85rem; }
.tweet-dot { color: var(--text-muted); }

.tweet-content {
  margin-top: 4px;
  word-wrap: break-word;
  white-space: pre-wrap;
}

.tweet-actions {
  display: flex;
  gap: 48px;
  margin-top: 10px;
}

.tweet-action {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-size: 0.85rem;
  cursor: pointer;
  transition: color 0.15s;
}

.tweet-action:hover { color: var(--accent); }
.tweet-action.liked { color: var(--danger); }
.tweet-action.retweeted { color: var(--retweet); }

.tweet-action svg { width: 18px; height: 18px; }

/* Profile */
.profile-header {
  padding: 20px 16px;
  border-bottom: 1px solid var(--border);
}

.profile-info { display: flex; gap: 16px; align-items: flex-start; }

.profile-avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  font-weight: 700;
  color: white;
  flex-shrink: 0;
}

.profile-details { flex: 1; }
.profile-details h2 { font-size: 1.3rem; }
.profile-details .username { color: var(--text-muted); font-size: 0.9rem; }
.profile-details .bio { margin-top: 8px; color: var(--text); }

.profile-stats {
  display: flex;
  gap: 20px;
  margin-top: 12px;
  font-size: 0.9rem;
}

.profile-stats span { color: var(--text-muted); }
.profile-stats strong { color: var(--text); }

/* Search */
.search-bar {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}

.search-bar input {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 9999px;
  padding: 10px 16px;
  color: var(--text);
  font-size: 0.95rem;
  outline: none;
}

.search-bar input:focus { border-color: var(--accent); }

/* Loading */
.loading {
  text-align: center;
  padding: 30px;
  color: var(--text-muted);
}

.empty {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-muted);
}

/* Retweet banner */
.retweet-banner {
  font-size: 0.8rem;
  color: var(--text-muted);
  padding: 4px 16px 0 64px;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: white;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 0.9rem;
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
  z-index: 1000;
}

.toast.show { opacity: 1; }

/* Suggestions */
.suggestion-card {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
}

.suggestion-card .details { flex: 1; }
.suggestion-card .details h4 { font-size: 0.9rem; }
.suggestion-card .details span { font-size: 0.8rem; color: var(--text-muted); }

/* Responsive */
@media (max-width: 620px) {
  .container { border: none; }
  .tweet-actions { gap: 24px; }
}