/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #0c0c14;
  --bg2:       #13131f;
  --bg3:       #1b1b2e;
  --border:    rgba(255,255,255,0.08);
  --text:      #e8e8f0;
  --text-muted:#7f7f9f;
  --text-dim:  #4a4a6a;

  --gpt:       #10a37f;
  --gpt-dim:   rgba(16,163,127,0.12);
  --gpt-border:rgba(16,163,127,0.30);

  --claude:    #d97706;
  --claude-dim:rgba(217,119,6,0.12);
  --claude-border:rgba(217,119,6,0.30);

  --gemini:    #4285f4;
  --gemini-dim:rgba(66,133,244,0.12);
  --gemini-border:rgba(66,133,244,0.30);

  --danger:    #ef4444;
  --danger-dim:rgba(239,68,68,0.12);

  --radius:    12px;
  --radius-sm: 8px;
  --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

html, body {
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ── Screens ── */
.screen { display: none; min-height: 100vh; }
.screen.active { display: flex; }

/* ── Landing ── */
.screen#screen-landing { align-items: center; justify-content: center; }

.landing-wrap {
  position: relative;
  width: 100%;
  max-width: 700px;
  padding: 3rem 2rem;
  text-align: center;
  overflow: hidden;
}

.landing-glow {
  position: absolute;
  inset: -50%;
  background: radial-gradient(ellipse 60% 50% at 50% 30%,
    rgba(16,163,127,0.07) 0%,
    rgba(66,133,244,0.06) 50%,
    transparent 75%);
  pointer-events: none;
  z-index: 0;
}

.landing-wrap > * { position: relative; z-index: 1; }

.title-badge {
  display: inline-block;
  padding: 4px 14px;
  background: linear-gradient(135deg, var(--gpt), var(--gemini));
  border-radius: 100px;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: #fff;
  margin-bottom: 1.25rem;
}

.landing-title {
  font-size: clamp(2rem, 6vw, 3.2rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #fff;
  margin-bottom: 0.75rem;
}

.landing-sub {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 2.25rem;
}

/* Combatants row */
.combatants {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.combatant {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.combatant-logo {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  color: #fff;
  box-shadow: 0 0 0 2px rgba(255,255,255,0.06);
}

.gpt-logo   { background: var(--gpt); }
.claude-logo{ background: var(--claude); }
.gemini-logo{ background: var(--gemini); }

.vs-badge {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-dim);
  letter-spacing: 0.1em;
}

/* Topic form */
.topic-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: center;
  margin-bottom: 1rem;
}

.input-wrap {
  display: flex;
  align-items: center;
  width: 100%;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.2s;
}

.input-wrap:focus-within {
  border-color: rgba(16,163,127,0.5);
  box-shadow: 0 0 0 3px rgba(16,163,127,0.08);
}

.input-prefix {
  padding: 0.85rem 1rem;
  font-size: 0.9rem;
  color: var(--text-muted);
  white-space: nowrap;
  border-right: 1px solid var(--border);
  flex-shrink: 0;
}

#topic-input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  padding: 0.85rem 1rem;
  font-size: 1rem;
  color: var(--text);
  font-family: var(--font);
  min-width: 0;
}

#topic-input::placeholder { color: var(--text-dim); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, opacity 0.15s;
  font-family: var(--font);
  text-decoration: none;
}

.btn:hover  { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-start {
  background: linear-gradient(135deg, var(--gpt) 0%, #0d8a6b 100%);
  color: #fff;
  box-shadow: 0 4px 20px rgba(16,163,127,0.35);
  width: 100%;
  max-width: 260px;
  justify-content: center;
}

.btn-start:hover { box-shadow: 0 6px 24px rgba(16,163,127,0.5); }

.btn-end {
  background: var(--danger-dim);
  color: var(--danger);
  border: 1px solid rgba(239,68,68,0.3);
  padding: 0.55rem 1.1rem;
  font-size: 0.85rem;
}

.btn-end:hover { background: rgba(239,68,68,0.2); }

/* Shake animation */
@keyframes shake {
  0%,100% { transform: translateX(0); }
  25% { transform: translateX(-6px); }
  75% { transform: translateX(6px); }
}
.shake { animation: shake 0.35s ease; }

/* API warning */
.api-warning {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(239,68,68,0.1);
  border: 1px solid rgba(239,68,68,0.3);
  border-radius: var(--radius-sm);
  padding: 0.6rem 1rem;
  font-size: 0.85rem;
  color: #fca5a5;
  margin-bottom: 1rem;
}

.landing-footnote {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 1.5rem;
}

.hidden { display: none !important; }

/* ── Battle Screen ── */
.screen#screen-battle {
  flex-direction: column;
  align-items: stretch;
}

.battle-layout {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* Topbar */
.battle-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 1.5rem;
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
  gap: 1rem;
  flex-shrink: 0;
  flex-wrap: wrap;
}

.battle-topic {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  min-width: 0;
}

.battle-topic-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  text-transform: uppercase;
  flex-shrink: 0;
}

.battle-topic-value {
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 400px;
}

.battle-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-shrink: 0;
}

/* Progress pill */
.progress-pill {
  position: relative;
  width: 130px;
  height: 28px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 100px;
  overflow: hidden;
}

.progress-fill {
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 0%;
  background: linear-gradient(90deg, var(--gpt), var(--gemini));
  border-radius: 100px;
  transition: width 0.5s ease;
}

.progress-label {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.05em;
  text-shadow: 0 1px 3px rgba(0,0,0,0.5);
}

/* Chat feed */
.chat-feed {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  scroll-behavior: smooth;
}

.chat-feed::-webkit-scrollbar { width: 6px; }
.chat-feed::-webkit-scrollbar-track { background: transparent; }
.chat-feed::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

/* Round divider */
.round-divider {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin: 0.5rem 0;
  color: var(--text-dim);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.round-divider::before,
.round-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* Message cards */
.message {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-width: 720px;
  width: 100%;
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  border: 1px solid;
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.35s ease, transform 0.35s ease;
}

.message.visible {
  opacity: 1;
  transform: translateY(0);
}

.message-openai {
  background: var(--gpt-dim);
  border-color: var(--gpt-border);
  align-self: flex-start;
}

.message-claude {
  background: var(--claude-dim);
  border-color: var(--claude-border);
  align-self: center;
}

.message-gemini {
  background: var(--gemini-dim);
  border-color: var(--gemini-border);
  align-self: flex-end;
}

.message-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.ai-avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.6rem;
  font-weight: 800;
  letter-spacing: 0.03em;
  color: #fff;
  flex-shrink: 0;
}

.ai-name {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.message-body {
  font-size: 0.95rem;
  color: var(--text);
  line-height: 1.65;
}

/* Session end divider */
.session-end-divider {
  text-align: center;
  padding: 1rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  margin-top: 0.5rem;
}

/* Status bar */
.status-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.7rem 1.5rem;
  background: var(--bg2);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.typing-indicator {
  display: flex;
  gap: 4px;
}

.typing-indicator span {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--text-muted);
  animation: bounce 1.2s ease-in-out infinite;
}
.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }

@keyframes bounce {
  0%,80%,100% { transform: scale(1); opacity: 0.5; }
  40%          { transform: scale(1.3); opacity: 1; }
}

#status-text {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ── End Screen ── */
.screen#screen-end { align-items: center; justify-content: center; }

.end-wrap {
  text-align: center;
  max-width: 480px;
  padding: 3rem 2rem;
}

.end-trophy {
  font-size: 4rem;
  margin-bottom: 1rem;
  filter: drop-shadow(0 0 20px rgba(255,215,0,0.4));
}

.end-title {
  font-size: 2.2rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 0.75rem;
}

.end-message {
  color: var(--text-muted);
  font-size: 1rem;
  margin-bottom: 2rem;
  line-height: 1.7;
}

.end-stats {
  display: flex;
  gap: 2rem;
  justify-content: center;
  margin-bottom: 2rem;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--gpt), var(--gemini));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ── End Screen: Verdict ── */
.end-verdict {
  width: 100%;
  max-width: 560px;
  margin: 0 auto 1.75rem;
  text-align: left;
}

.verdict-header {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  margin-bottom: 0.9rem;
  text-align: center;
}

.verdict-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.verdict-sub {
  font-size: 0.75rem;
  color: var(--text-dim);
  font-style: italic;
}

.verdict-cards {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.verdict-card {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.35s ease, transform 0.35s ease;
}

.verdict-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.verdict-avatar {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.55rem;
  font-weight: 800;
  letter-spacing: 0.03em;
  color: #fff;
  flex-shrink: 0;
  margin-top: 1px;
}

.verdict-text {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.verdict-loading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  font-size: 0.82rem;
  color: var(--text-dim);
  margin-bottom: 1.5rem;
}

.btn-review {
  background: var(--bg3);
  color: var(--text-muted);
  border: 1px solid var(--border);
  padding: 0.75rem 1.5rem;
  justify-content: center;
}

.btn-review:hover {
  background: var(--bg2);
  color: var(--text);
  border-color: rgba(255,255,255,0.18);
}

.end-actions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

/* ── Error state ── */
.error-card {
  background: rgba(239,68,68,0.1);
  border: 1px solid rgba(239,68,68,0.3);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  font-size: 0.9rem;
  color: #fca5a5;
  align-self: center;
  max-width: 500px;
  width: 100%;
  text-align: center;
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.35s, transform 0.35s;
}
.error-card.visible { opacity: 1; transform: translateY(0); }

/* ── Responsive ── */
@media (max-width: 600px) {
  .battle-topbar { flex-direction: column; align-items: flex-start; }
  .battle-topic-value { max-width: 100%; }
  .message-claude { align-self: flex-start; }
  .message-gemini { align-self: flex-start; }
  .progress-pill { width: 100px; }
  .combatants { gap: 0.6rem; }
}