:root {
  --bg: var(--tg-theme-bg-color, #0f1115);
  --text: var(--tg-theme-text-color, #f2f2f2);
  --hint: var(--tg-theme-hint-color, #8a8f98);
  --button: var(--tg-theme-button-color, #34c77b);
  --button-text: var(--tg-theme-button-text-color, #0f1115);
  --card: #1a1d23;
  --border: #2a2e37;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

.shell { max-width: 480px; margin: 0 auto; padding: 24px 16px 40px; }

h1 { font-size: 22px; margin: 8px 0 4px; }
.sub { color: var(--hint); font-size: 14px; margin: 0 0 20px; }

form { display: flex; flex-direction: column; gap: 12px; }

input[type="text"] {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
  font-size: 16px;
  color: var(--text);
}

button {
  border: none;
  border-radius: 12px;
  padding: 14px 16px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
}

#checkButton {
  background: var(--button);
  color: var(--button-text);
}

#checkButton:disabled { opacity: 0.6; }

.error { color: #ff6b6b; font-size: 14px; margin-top: 12px; }

.loading-screen { text-align: center; padding: 60px 0; color: var(--hint); }

.loader {
  display: inline-block;
  width: 28px; height: 28px;
  border: 3px solid var(--border);
  border-top-color: var(--button);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-bottom: 16px;
}

@keyframes spin { to { transform: rotate(360deg); } }

.score-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  text-align: center;
  margin-bottom: 20px;
}

.channel-row { display: flex; align-items: center; gap: 10px; justify-content: center; margin-bottom: 12px; }
.channel-row img { width: 32px; height: 32px; border-radius: 50%; object-fit: cover; }
.channel-row span { color: var(--hint); font-size: 14px; }

.score-value { font-size: 48px; font-weight: 700; line-height: 1; }
.score-label { color: var(--hint); font-size: 15px; margin-top: 6px; }
.score-percentile { color: var(--hint); font-size: 13px; margin-top: 4px; }

.problems { margin: 0 0 20px; padding: 0; list-style: none; }
.problems li {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 14px;
  margin-bottom: 8px;
  font-size: 14px;
}
.problems .block-label { color: var(--hint); font-size: 12px; display: block; margin-bottom: 2px; }

.tail-stack { display: flex; flex-direction: column; gap: 10px; }

.tail-button {
  display: block;
  text-decoration: none;
  text-align: center;
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 12px;
  padding: 14px 16px;
  font-size: 15px;
  font-weight: 600;
}

.achievement-button { background: var(--button); color: var(--button-text); border: none; }

.tail-message { text-align: center; font-size: 13px; color: var(--hint); min-height: 18px; margin: 10px 0 0; }

.footer-note {
  text-align: center;
  color: var(--hint);
  font-size: 12px;
  margin-top: 28px;
}
.footer-note a { color: var(--hint); }