:root {
  color-scheme: light dark;
  --bg: #0f172a;
  --bg-alt: rgba(148, 163, 184, 0.1);
  --text: #e2e8f0;
  --accent: #38bdf8;
  --accent-strong: #0ea5e9;
  --danger: #f87171;
  --shadow: rgba(15, 23, 42, 0.3);
  --font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-family);
  background: radial-gradient(circle at top, rgba(56, 189, 248, 0.2), transparent),
    radial-gradient(circle at 20% 80%, rgba(14, 165, 233, 0.15), transparent),
    var(--bg);
  color: var(--text);
}

.app {
  max-width: 1080px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
  display: grid;
  gap: 1.5rem;
}

.app__header {
  text-align: center;
  padding: 1rem 1.5rem;
  background: rgba(15, 23, 42, 0.75);
  backdrop-filter: blur(8px);
  border-radius: 18px;
  box-shadow: 0 15px 40px -20px var(--shadow);
}

.app__header h1 {
  margin: 0;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
}

.app__header p {
  margin: 0.5rem 0 0;
  color: rgba(226, 232, 240, 0.7);
}

.panel {
  padding: 1.25rem;
  background: rgba(15, 23, 42, 0.8);
  border-radius: 18px;
  box-shadow: 0 20px 45px -25px var(--shadow);
  backdrop-filter: blur(10px);
}

.panel--controls {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.control-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

label {
  font-size: 0.95rem;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  color: rgba(226, 232, 240, 0.7);
}

select {
  padding: 0.45rem 0.75rem;
  background: rgba(15, 23, 42, 0.9);
  color: var(--text);
  border: 1px solid rgba(148, 163, 184, 0.35);
  border-radius: 0.75rem;
  min-width: 160px;
}

.btn {
  border: none;
  padding: 0.65rem 1.2rem;
  border-radius: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  background: rgba(148, 163, 184, 0.2);
  color: var(--text);
}

.btn:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 12px 20px -16px var(--shadow);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn--primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #0b1120;
}

.status {
  min-height: 1.25rem;
  font-size: 0.95rem;
  color: rgba(148, 163, 184, 0.85);
}

.conversation {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-height: 520px;
  overflow-y: auto;
}

.message {
  padding: 1rem;
  border-radius: 1rem;
  background: rgba(30, 41, 59, 0.65);
  border: 1px solid rgba(148, 163, 184, 0.25);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.message--assistant {
  border-left: 4px solid var(--accent);
}

.message--user {
  border-left: 4px solid rgba(74, 222, 128, 0.75);
}

.message__meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: rgba(148, 163, 184, 0.6);
}

.message__content {
  white-space: pre-wrap;
  line-height: 1.6;
}

.panel--score {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.score-card {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.score-card__label {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.75rem;
  color: rgba(148, 163, 184, 0.6);
}

.score-card__value {
  font-size: clamp(2.2rem, 6vw, 3rem);
  font-weight: 700;
  color: var(--accent);
}

.tts-player {
  width: 100%;
}

@media (max-width: 768px) {
  .app {
    padding: 1.25rem 1rem 2.5rem;
  }

  .panel--controls {
    gap: 0.85rem;
  }

  .panel--score {
    flex-direction: column;
    align-items: stretch;
  }
}