@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
  --primary: #1a98d8;
  --primary-light: #2aade8;
  --primary-dark: #1478b0;
  --secondary: #ffffff;
  --secondary-light: #f5f8fa;
  --secondary-dark: #e0e8f0;
  --accent: #f4520d;
  --accent-hover: #ff6b2e;
  --accent-light: #ff8c5a;
  --bg-primary: #0a2a3f;
  --bg-secondary: #0d3550;
  --bg-tertiary: #104060;
  --bg-elevated: #145070;
  --bg-hover: #1a6080;
  --surface-glass: rgba(250,237,209,0.05);
  --border-subtle: rgba(250,237,209,0.08);
  --border-default: rgba(250,237,209,0.15);
  --border-strong: rgba(250,237,209,0.25);
  --text-primary: #f0f4f8;
  --text-secondary: #d0d8e0;
  --text-tertiary: #a0b8cc;
  --accent-gradient: linear-gradient(135deg, #f4520d 0%, #ff6b2e 50%, #ff8c5a 100%);
  --accent-gradient-hover: linear-gradient(135deg, #ff6b2e 0%, #ff8c5a 50%, #ffaa80 100%);
  --primary-gradient: linear-gradient(135deg, #0e7ab0 0%, #1387c0 100%);
  --success: #34d399;
  --warning: #fbbf24;
  --error: #f87171;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.4);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.5);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.6);
  --shadow-glow: 0 0 40px rgba(244,82,13,0.2);
  --shadow-primary: 0 0 40px rgba(19,135,192,0.3);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --transition-fast: 0.15s cubic-bezier(0.4,0,0.2,1);
  --transition-normal: 0.25s cubic-bezier(0.4,0,0.2,1);
  --transition-slow: 0.4s cubic-bezier(0.4,0,0.2,1);
}

[data-theme="light"] {
  --bg-primary: #ffffff;
  --bg-secondary: #f7f9fc;
  --bg-tertiary: #f0f2f6;
  --bg-elevated: #ffffff;
  --bg-hover: #e8ecf1;
  --surface-glass: rgba(19,135,192,0.04);
  --border-subtle: #d5dbe4;
  --border-default: #b0bdd0;
  --border-strong: #8ea2b8;
  --text-primary: #111827;
  --text-secondary: #374151;
  --text-tertiary: #6b7280;
  --secondary: #1e3a5f;
  --accent-gradient: linear-gradient(135deg, #f4520d 0%, #ff6b2e 100%);
  --accent-gradient-hover: linear-gradient(135deg, #ff6b2e 0%, #ff8c5a 100%);
  --primary-gradient: linear-gradient(135deg, #1387c0 0%, #1a9dd6 100%);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
  --shadow-glow: 0 0 30px rgba(244,82,13,0.15);
  --shadow-primary: 0 0 30px rgba(19,135,192,0.15);
}

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

*:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}

select:focus-visible, input:focus-visible, textarea:focus-visible, button:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

.app-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(19,135,192,0.2) 0%, transparent 60%),
    linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  border-bottom: 1px solid var(--border-subtle);
  gap: 16px;
  flex-wrap: wrap;
  backdrop-filter: blur(12px);
  background: rgba(250,237,209,0.02);
  position: sticky;
  top: 0;
  z-index: 50;
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 700;
  color: var(--secondary);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.navbar-brand svg {
  width: 24px;
  height: 24px;
  color: var(--primary);
}

.navbar-center {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  justify-content: center;
  max-width: 400px;
}

.model-display {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--bg-tertiary);
}

.model-display svg {
  width: 14px;
  height: 14px;
  color: var(--primary);
  flex-shrink: 0;
}

.model-text {
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.navbar-actions { display: flex; align-items: center; gap: 6px; }

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  background: var(--bg-hover);
  color: var(--primary);
  border-color: var(--primary);
}

.icon-btn:active { transform: scale(0.92); }
.icon-btn svg { width: 16px; height: 16px; }

/* ====== 主体 ====== */
.main-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px;
  height: calc(100vh - 73px);
  display: flex;
  flex-direction: column;
}

.translate-wrapper {
  flex: 1;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  background: var(--bg-secondary);
  overflow: hidden;
  box-shadow: var(--shadow-lg), 0 0 60px rgba(19,135,192,0.1);
  min-height: 0;
}

/* ====== 控制栏 ====== */
.control-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 18px;
  border-bottom: 1px solid var(--border-subtle);
  background: var(--surface-glass);
  backdrop-filter: blur(12px);
  flex-shrink: 0;
}

.control-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.control-right {
  display: flex;
  align-items: center;
  gap: 6px;
}

.lang-select {
  padding: 8px 14px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  font-size: 13px;
  font-weight: 600;
  color: var(--secondary);
  font-family: var(--font-sans);
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition-fast);
  min-width: 120px;
}

.lang-select:hover { border-color: var(--primary); }
.lang-select option { background: var(--bg-elevated); color: var(--text-primary); }

.swap-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-default);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-normal);
  flex-shrink: 0;
}

.swap-btn:hover {
  background: var(--bg-hover);
  color: var(--primary);
  transform: rotate(180deg);
}

.translate-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 20px;
  border: none;
  border-radius: var(--radius-md);
  background: var(--accent-gradient);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all var(--transition-normal);
  letter-spacing: -0.01em;
  box-shadow: 0 2px 8px rgba(244,82,13,0.3);
}

.translate-btn:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(244,82,13,0.4);
}

.translate-btn:active:not(:disabled) { transform: scale(0.97); }
.translate-btn:disabled { opacity: 0.35; cursor: not-allowed; box-shadow: none; }

.translate-btn svg { width: 16px; height: 16px; }

/* ====== 左右分栏 ====== */
.split-panels {
  flex: 1;
  display: flex;
  min-height: 0;
}

.panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.panel-source { border-right: 1px solid var(--border-subtle); }

.panel-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.panel-footer {
  padding: 10px 18px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  background: var(--surface-glass);
  flex-shrink: 0;
}

.text-input {
  flex: 1;
  width: 100%;
  padding: 20px 24px;
  background: transparent;
  border: none;
  outline: none;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-primary);
  font-family: var(--font-sans);
  resize: none;
}

.text-input::placeholder { color: var(--text-tertiary); }

.result-display {
  flex: 1;
  padding: 20px 24px;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-primary);
  overflow-y: auto;
  white-space: pre-wrap;
  word-break: break-word;
}

.result-display.empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--text-tertiary);
  font-size: 14px;
  gap: 12px;
}

.result-display.empty svg {
  width: 48px;
  height: 48px;
  opacity: 0.25;
  color: var(--primary);
}

.char-count {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-tertiary);
  font-variant-numeric: tabular-nums;
}

.char-count.over { color: var(--error); }

.tool-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.tool-btn:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
  border-color: var(--primary);
}

.tool-btn:active { transform: scale(0.92); }
.tool-btn svg { width: 16px; height: 16px; }

.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid rgba(255,255,255,0.25);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s cubic-bezier(0.6,0.3,0.3,1) infinite;
}

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

.skeleton {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-sm);
  height: 14px;
  margin-bottom: 10px;
  background: var(--bg-hover);
}

.skeleton::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent 0%, var(--bg-tertiary) 50%, transparent 100%);
  animation: skeleton-shimmer 1.5s ease-in-out infinite;
}

.skeleton:nth-child(2) { width: 75%; }
.skeleton:nth-child(3) { width: 50%; }

@keyframes skeleton-shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

.toast {
  position: fixed;
  top: 20px;
  right: 20px;
  padding: 12px 18px;
  border-radius: var(--radius-md);
  font-size: 13px;
  font-weight: 500;
  z-index: 1000;
  transform: translateX(120%) scale(0.9);
  opacity: 0;
  transition: all 0.35s cubic-bezier(0.4,0,0.2,1);
  backdrop-filter: blur(8px);
}

.toast.show { transform: translateX(0) scale(1); opacity: 1; }
.toast.success { background: rgba(52,211,153,0.15); color: var(--success); border: 1px solid rgba(52,211,153,0.2); }
.toast.error { background: rgba(248,113,113,0.15); color: var(--error); border: 1px solid rgba(248,113,113,0.2); }
.toast.info { background: rgba(19,135,192,0.15); color: var(--primary-light); border: 1px solid rgba(19,135,192,0.2); }

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  backdrop-filter: blur(4px);
}

.modal-overlay.active { opacity: 1; visibility: visible; }

.modal {
  background: var(--bg-elevated);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  padding: 24px;
  width: 90%;
  max-width: 480px;
  max-height: 80vh;
  overflow-y: auto;
  transform: scale(0.95) translateY(10px);
  transition: transform 0.3s cubic-bezier(0.4,0,0.2,1);
  box-shadow: var(--shadow-lg);
}

.modal-overlay.active .modal { transform: scale(1) translateY(0); }

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.modal-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--secondary);
  letter-spacing: -0.01em;
}

.form-section { margin-bottom: 16px; }

.form-label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.form-input, .form-select {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  font-size: 14px;
  color: var(--text-primary);
  font-family: var(--font-sans);
  outline: none;
  transition: all var(--transition-fast);
}

.form-input:focus, .form-select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(19,135,192,0.2);
}

.form-input::placeholder { color: var(--text-tertiary); }

.form-actions {
  display: flex;
  gap: 8px;
  margin-top: 20px;
}

.btn {
  padding: 10px 18px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 13px;
  font-weight: 600;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn:active { transform: scale(0.96); }

.btn-primary {
  background: var(--accent-gradient);
  color: #fff;
}

.btn-primary:hover { box-shadow: var(--shadow-glow); }

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-default);
}

.btn-secondary:hover { background: var(--bg-hover); border-color: var(--primary); }

.api-key-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 14px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 8px;
  transition: all var(--transition-fast);
}

.api-key-item:hover { border-color: var(--primary); }

.api-key-info { display: flex; flex-direction: column; gap: 3px; }

.api-key-provider {
  font-size: 13px;
  font-weight: 600;
  color: var(--secondary);
}

.api-key-masked {
  font-size: 12px;
  color: var(--text-tertiary);
  font-family: 'SF Mono', 'Fira Code', monospace;
}

.footer {
  text-align: center;
  padding: 16px;
  font-size: 12px;
  color: var(--text-tertiary);
}

@media (max-width: 768px) {
  .navbar { padding: 10px 16px; }
  .main-container { padding: 12px; height: auto; }
  .translate-wrapper { min-height: calc(100vh - 140px); }
  .control-bar {
    flex-direction: column;
    gap: 12px;
    padding: 14px;
  }
  .control-left, .control-right {
    width: 100%;
    justify-content: space-between;
  }
  .translate-btn { flex: 1; padding: 10px 20px; }
  .split-panels {
    flex-direction: column;
  }
  .panel-source { border-right: none; border-bottom: 1px solid var(--border-subtle); }
  .panel { min-height: 200px; }
}