/* ===== AI 產圖工具 — 深色主題 ===== */

:root {
  --bg-primary: #0a0e1a;
  --bg-card: #12162a;
  --bg-card-hover: #1a1f38;
  --bg-input: #0d1120;
  --border: #2a3050;
  --border-focus: #6366f1;
  --text-primary: #e8eaf0;
  --text-secondary: #8b90a8;
  --text-muted: #5a5f78;
  --accent: #6366f1;
  --accent-hover: #818cf8;
  --accent-glow: rgba(99, 102, 241, 0.3);
  --success: #22c55e;
  --danger: #ef4444;
  --radius: 12px;
  --radius-lg: 16px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: 'Noto Sans TC', 'Inter', system-ui, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ===== 背景光暈 ===== */

.bg-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.15;
  pointer-events: none;
  z-index: 0;
}

.bg-glow-1 {
  width: 600px;
  height: 600px;
  background: #6366f1;
  top: -200px;
  right: -100px;
}

.bg-glow-2 {
  width: 500px;
  height: 500px;
  background: #8b5cf6;
  bottom: -150px;
  left: -100px;
}

/* ===== 主容器 ===== */

.app-container {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

/* ===== Header ===== */

.app-header {
  text-align: center;
  margin-bottom: 2rem;
}

.back-link {
  display: inline-block;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  margin-bottom: 1rem;
  transition: color var(--transition);
}

.back-link:hover {
  color: var(--accent-hover);
}

.app-header h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.3rem;
}

.subtitle {
  color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
}

/* ===== 輸入卡片 ===== */

.input-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: border-color var(--transition);
}

.input-card:focus-within {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.input-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.5rem;
}

.prompt-textarea {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-family: 'Noto Sans TC', system-ui, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  padding: 1rem;
  resize: vertical;
  min-height: 120px;
  transition: border-color var(--transition);
}

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

.prompt-textarea:focus {
  outline: none;
  border-color: var(--border-focus);
}

/* ===== 選項列 ===== */

.options-row {
  display: flex;
  gap: 1rem;
  align-items: flex-end;
  margin-top: 1rem;
  flex-wrap: wrap;
}

.option-group {
  flex: 0 0 auto;
}

.option-label {
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.3rem;
}

.option-select {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.9rem;
  padding: 0.6rem 2rem 0.6rem 0.8rem;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238b90a8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.6rem center;
  transition: border-color var(--transition);
}

.option-select:focus {
  outline: none;
  border-color: var(--border-focus);
}

/* ===== 產生按鈕 ===== */

.btn-generate {
  flex: 1;
  min-width: 160px;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  border: none;
  border-radius: 8px;
  color: #fff;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  padding: 0.7rem 1.5rem;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), opacity var(--transition);
  position: relative;
  overflow: hidden;
}

.btn-generate:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 4px 20px var(--accent-glow);
}

.btn-generate:active:not(:disabled) {
  transform: translateY(0);
}

.btn-generate:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.spinner {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  vertical-align: middle;
  margin-right: 0.3rem;
}

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

/* ===== 結果卡片 ===== */

.result-section {
  margin-top: 2rem;
  animation: fadeInUp 0.4s ease;
}

.result-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  overflow: hidden;
}

.result-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.result-header h2 {
  font-size: 1.1rem;
  font-weight: 600;
}

.result-time {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.result-image-wrapper {
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-input);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 200px;
}

.result-image {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius);
}

.result-actions {
  display: flex;
  gap: 0.8rem;
  margin-top: 1rem;
}

.btn-action {
  flex: 1;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.6rem 1rem;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition);
}

.btn-action:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent);
}

/* ===== 錯誤區 ===== */

.error-section {
  margin-top: 2rem;
  animation: fadeInUp 0.4s ease;
}

.error-card {
  background: rgba(239, 68, 68, 0.08);
  border: 1px solid rgba(239, 68, 68, 0.3);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
}

.error-icon {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.error-message {
  color: #fca5a5;
  font-size: 0.95rem;
  white-space: pre-wrap;
  word-break: break-word;
}

/* ===== 歷史記錄 ===== */

.history-section {
  margin-top: 2.5rem;
}

.history-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

.history-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
}

.history-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  transition: transform var(--transition), border-color var(--transition);
}

.history-item:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}

.history-item img {
  width: 100%;
  height: 150px;
  object-fit: cover;
  display: block;
}

.history-item-info {
  padding: 0.5rem 0.75rem;
}

.history-item-time {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  color: var(--text-muted);
}

.history-item-prompt {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 0.2rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ===== 動畫 ===== */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== RWD ===== */

@media (max-width: 600px) {
  .app-container {
    padding: 1rem 1rem 3rem;
  }

  .app-header h1 {
    font-size: 1.5rem;
  }

  .options-row {
    flex-direction: column;
  }

  .option-group {
    width: 100%;
  }

  .option-select {
    width: 100%;
  }

  .btn-generate {
    width: 100%;
  }

  .result-actions {
    flex-direction: column;
  }

  .history-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  }
}