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

:root {
  --bg: #f5f5f7;
  --surface: #ffffff;
  --surface2: #f0f0f5;
  --border: #e0e0e8;
  --text: #1a1a2e;
  --text2: #6b6b80;
  --primary: #6366f1;
  --primary-hover: #5254d8;
  --success: #16a34a;
  --accent: #8b5cf6;
  --radius: 10px;
  --radius-sm: 6px;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ── Navbar ── */
.navbar {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}

.nav-container {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  height: 56px;
}

.nav-logo {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  gap: 4px;
}

.nav-links a {
  color: var(--text2);
  text-decoration: none;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  transition: all 0.15s;
}

.nav-links a:hover {
  color: var(--text);
  background: var(--surface2);
}

.nav-links a.active {
  color: var(--primary);
  background: rgba(99, 102, 241, 0.1);
}

/* ── Main ── */
.container {
  max-width: 700px;
  margin: 0 auto;
  padding: 32px 20px;
  flex: 1;
  width: 100%;
}

.page-content {
  max-width: 700px;
}

.hero {
  text-align: center;
  margin-bottom: 32px;
}

.hero h1 {
  font-size: 1.8rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  color: var(--text2);
  margin-top: 8px;
  font-size: 0.95rem;
}

/* ── Tabs ── */
.mode-tabs,
.input-tabs {
  display: flex;
  gap: 4px;
  background: var(--surface);
  padding: 4px;
  border-radius: var(--radius);
  margin-bottom: 20px;
}

.tab-btn {
  flex: 1;
  padding: 10px 16px;
  border: none;
  background: transparent;
  color: var(--text2);
  font-size: 0.9rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s;
  font-weight: 500;
}

.tab-btn:hover {
  color: var(--text);
  background: var(--surface2);
}

.tab-btn.active {
  background: var(--primary);
  color: #fff;
}

.tab-btn.small {
  font-size: 0.85rem;
  padding: 8px 12px;
}

.mode-panel,
.input-panel {
  display: none;
}

.mode-panel.active,
.input-panel.active {
  display: block;
}

/* ── Drop Zone ── */
.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 48px 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  background: var(--surface);
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--primary);
  background: rgba(99, 102, 241, 0.05);
}

.drop-content svg {
  margin-bottom: 12px;
}

.drop-content p {
  color: var(--text2);
  font-size: 0.95rem;
}

.drop-content .link {
  color: var(--primary);
  text-decoration: underline;
  cursor: pointer;
}

.hint {
  font-size: 0.8rem;
  color: var(--text2);
  margin-top: 8px;
}

/* ── URL Input ── */
.url-input-group {
  display: flex;
  gap: 8px;
}

.url-field {
  flex: 1;
  padding: 12px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.9rem;
  outline: none;
  transition: border-color 0.15s;
}

.url-field:focus {
  border-color: var(--primary);
}

.url-field::placeholder {
  color: var(--text2);
  opacity: 0.6;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
}

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

.btn-primary {
  background: var(--primary);
  color: #fff;
  width: 100%;
  padding: 14px;
  margin-top: 16px;
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-hover);
}

.btn-secondary {
  background: var(--surface2);
  color: var(--text);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--border);
}

.btn-success {
  background: var(--success);
  color: #fff;
}

/* ── Select ── */
.select {
  width: 100%;
  padding: 10px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.9rem;
  outline: none;
  cursor: pointer;
}

.select:focus {
  border-color: var(--primary);
}

.format-section {
  margin-top: 24px;
}

/* 精度设置 */
.precision-settings {
  margin-top: 16px;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  overflow: hidden;
  background: #fafafa;
}
.precision-settings summary {
  padding: 10px 14px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  color: #555;
  user-select: none;
}
.precision-settings summary:hover {
  background: #f3f4f6;
}
.precision-body {
  padding: 12px 14px 14px;
  border-top: 1px solid #e5e7eb;
}
.precision-row {
  margin-bottom: 14px;
}
.precision-row:last-child {
  margin-bottom: 0;
}
.precision-row label {
  display: block;
  font-size: 12px;
  font-weight: 500;
  color: #444;
  margin-bottom: 4px;
}
.precision-row select {
  width: 100%;
  padding: 6px 10px;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  font-size: 13px;
  background: white;
}
.precision-row input[type="range"] {
  width: 100%;
  margin: 4px 0;
  accent-color: #6366f1;
}
.range-labels {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: #999;
}

.format-row {
  display: flex;
  align-items: flex-end;
  gap: 12px;
}

.format-group {
  flex: 1;
}

.format-group label {
  display: block;
  font-size: 0.8rem;
  color: var(--text2);
  margin-bottom: 6px;
  font-weight: 500;
}

.arrow {
  font-size: 1.5rem;
  color: var(--primary);
  padding-bottom: 8px;
}

/* ── Status ── */
.status-panel {
  text-align: center;
  padding: 32px;
  margin-top: 20px;
  background: var(--surface);
  border-radius: var(--radius);
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top: 3px solid var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 12px;
}

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

/* ── Result ── */
.result-panel {
  text-align: center;
  padding: 32px;
  margin-top: 20px;
  background: var(--surface);
  border-radius: var(--radius);
}

.result-icon {
  margin-bottom: 12px;
}

.result-panel p {
  margin-bottom: 16px;
  font-size: 1.1rem;
}

.result-panel .btn {
  margin: 4px;
}

/* ── FAQ Page ── */
.page-content h1 {
  font-size: 1.5rem;
  margin-bottom: 24px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.faq-section {
  margin-bottom: 32px;
}

.faq-section h2 {
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.faq-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  overflow: hidden;
}

.faq-item summary {
  padding: 14px 16px;
  cursor: pointer;
  font-weight: 500;
  color: var(--text);
  font-size: 0.9rem;
  transition: color 0.15s;
}

.faq-item summary:hover {
  color: var(--primary);
}

.faq-item[open] summary {
  border-bottom: 1px solid var(--border);
}

.faq-item p {
  padding: 14px 16px;
  color: var(--text2);
  font-size: 0.88rem;
  line-height: 1.7;
}

/* ── Donate Page ── */
.donate-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 32px;
  text-align: center;
}

.donate-card h1 {
  font-size: 1.5rem;
  margin-bottom: 4px;
  background: none;
  -webkit-text-fill-color: var(--text);
}

.divider {
  height: 1px;
  background: var(--border);
  margin: 16px 0;
}

.donate-intro {
  color: var(--text2);
  font-size: 0.95rem;
  margin-bottom: 8px;
}

.qr-grid {
  display: flex;
  gap: 24px;
  justify-content: center;
  margin: 24px 0;
}

.qr-item {
  flex: 1;
  max-width: 220px;
}

.qr-item h3 {
  font-size: 0.9rem;
  margin-bottom: 12px;
  color: var(--text);
}

.qr-img {
  width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  display: block;
}

.qr-note {
  font-size: 0.8rem;
  color: var(--text2);
  margin-top: 8px;
}

.donate-alt {
  margin-top: 24px;
  text-align: left;
  color: var(--text2);
  font-size: 0.88rem;
}

.donate-alt ul {
  list-style: none;
  margin-top: 8px;
}

.donate-alt li {
  padding: 4px 0;
}

/* ── Footer ── */
.footer {
  text-align: center;
  padding: 24px;
  color: var(--text2);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
}

/* ── Responsive ── */
@media (max-width: 600px) {
  .nav-container {
    padding: 0 12px;
  }
  .container {
    padding: 20px 12px;
  }
  .format-row {
    flex-direction: column;
    align-items: stretch;
  }
  .arrow {
    display: none;
  }
  .qr-grid {
    flex-direction: column;
    align-items: center;
  }
  .drop-zone {
    padding: 32px 16px;
  }
}

/* ── Translate Page ── */
.translate-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
}

.translate-card h1 {
  font-size: 1.5rem;
  margin-bottom: 4px;
  background: none;
  -webkit-text-fill-color: initial;
}

.translate-intro {
  color: var(--text2);
  font-size: 0.9rem;
  margin-bottom: 24px;
}

.translate-controls {
  max-width: 700px;
  margin: 0 auto;
}

.lang-row {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-bottom: 16px;
}

.lang-select {
  flex: 1;
}

.btn-swap {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--surface);
  color: var(--primary);
  font-size: 1.2rem;
  cursor: pointer;
  transition: all 0.15s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-swap:hover {
  background: var(--surface2);
  border-color: var(--primary);
}

.text-area-row {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
}

.text-area-box {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.translate-textarea {
  width: 100%;
  min-height: 160px;
  padding: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.95rem;
  line-height: 1.6;
  resize: vertical;
  outline: none;
  font-family: inherit;
  transition: border-color 0.15s;
  box-sizing: border-box;
}

.translate-textarea:focus {
  border-color: var(--primary);
}

.translate-textarea::placeholder {
  color: var(--text2);
  opacity: 0.6;
}

.result-area {
  background: var(--surface2);
  cursor: default;
}

.textarea-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 4px 0;
  font-size: 0.8rem;
  color: var(--text2);
}

.btn-clear {
  background: none;
  border: none;
  color: var(--text2);
  cursor: pointer;
  font-size: 0.8rem;
  padding: 2px 8px;
  border-radius: 4px;
  transition: all 0.1s;
}

.btn-clear:hover {
  color: var(--text);
  background: var(--surface2);
}

.translate-btn {
  max-width: 200px;
  margin: 8px auto 12px;
}

.translate-status {
  font-size: 0.85rem;
  min-height: 1.2em;
}

.translate-status.success {
  color: var(--success);
}

.translate-status.error {
  color: #dc2626;
}

@media (max-width: 600px) {
  .text-area-row {
    flex-direction: column;
  }
  .translate-card {
    padding: 20px 16px;
  }
}