:root {
  --primary: #cc785c;
  --primary-active: #a9583e;
  --primary-disabled: #e6dfd8;
  --ink: #141413;
  --body: #3d3d3a;
  --body-strong: #252523;
  --muted: #6c6a64;
  --muted-soft: #8e8b82;
  --hairline: #e6dfd8;
  --hairline-soft: #ebe6df;
  --canvas: #faf9f5;
  --surface-soft: #f5f0e8;
  --surface-card: #efe9de;
  --surface-cream-strong: #e8e0d2;
  --surface-dark: #181715;
  --surface-dark-elevated: #252320;
  --surface-dark-soft: #1f1e1b;
  --on-primary: #ffffff;
  --on-dark: #faf9f5;
  --on-dark-soft: #a09d96;
  --accent-teal: #5db8a6;
  --accent-amber: #e8a55a;
  --success: #5db872;
  --warning: #d4a017;
  --error: #c64545;

  --font-display: "Cormorant Garamond", "EB Garamond", "Tiempos Headline", "Garamond", "Times New Roman", serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-code: "JetBrains Mono", ui-monospace, "SFMono-Regular", "Menlo", monospace;

  --r-xs: 4px;
  --r-sm: 6px;
  --r-md: 8px;
  --r-lg: 12px;
  --r-xl: 16px;
  --r-pill: 9999px;

  --s-xxs: 4px;
  --s-xs: 8px;
  --s-sm: 12px;
  --s-md: 16px;
  --s-lg: 24px;
  --s-xl: 32px;
  --s-xxl: 48px;
  --s-section: 96px;

  --transition: all 0.2s ease;
  --shadow-subtle: 0 1px 3px rgba(20, 20, 19, 0.08);
}

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.55;
  color: var(--body);
  background-color: var(--canvas);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  color: var(--primary-active);
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 500;
  color: var(--ink);
  letter-spacing: -0.02em;
}

h1 {
  font-size: 48px;
  line-height: 1.1;
  letter-spacing: -1px;
}

h2 {
  font-size: 36px;
  line-height: 1.15;
  letter-spacing: -0.5px;
}

h3 {
  font-size: 28px;
  line-height: 1.2;
  letter-spacing: -0.3px;
}

header {
  background-color: var(--canvas);
  border-bottom: 1px solid var(--hairline);
  position: sticky;
  top: 0;
  z-index: 100;
  height: 64px;
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--s-lg);
  height: 64px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header-left, .header-right {
  display: flex;
  align-items: center;
  gap: var(--s-md);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--ink);
}

.logo-icon {
  width: 32px;
  height: 32px;
  object-fit: contain;
}

.logo-text {
  display: flex;
  flex-direction: column;
}

.logo-cn {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 500;
  line-height: 1.2;
  color: var(--ink);
  letter-spacing: -0.02em;
}

.logo-en {
  font-size: 11px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  font-weight: 500;
}

.tools-link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background-color: transparent;
  border: 1px solid var(--hairline);
  border-radius: var(--r-md);
  color: var(--ink);
  font-size: 14px;
  font-weight: 500;
  transition: var(--transition);
}

.tools-link:hover {
  background-color: var(--surface-card);
  color: var(--primary);
}

.model-select {
  padding: 8px 14px;
  border: 1px solid var(--hairline);
  border-radius: var(--r-md);
  background-color: var(--canvas);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  min-width: 100px;
  transition: var(--transition);
}

.model-select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(204, 120, 92, 0.15);
}

.header-button {
  padding: 8px 16px;
  background-color: var(--canvas);
  border: 1px solid var(--hairline);
  border-radius: var(--r-md);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  color: var(--ink);
  cursor: pointer;
  transition: var(--transition);
}

.header-button:hover {
  background-color: var(--surface-card);
}

.user-menu {
  display: flex;
  align-items: center;
  gap: var(--s-sm);
}

.user-name {
  color: var(--muted);
  font-size: 14px;
  font-weight: 500;
}

main {
  max-width: 1200px;
  margin: 0 auto;
  min-height: calc(100vh - 140px);
}

footer {
  background-color: var(--surface-dark);
  padding: var(--s-xxl) 0;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--s-lg);
  text-align: center;
}

.footer-text {
  color: var(--on-dark-soft);
  font-size: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 20px;
  border-radius: var(--r-md);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  line-height: 1;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  text-decoration: none;
  height: 40px;
}

.btn-primary {
  background-color: var(--primary);
  color: var(--on-primary);
}

.btn-primary:hover {
  background-color: var(--primary-active);
}

.btn-secondary {
  background-color: var(--canvas);
  color: var(--ink);
  border: 1px solid var(--hairline);
}

.btn-secondary:hover {
  background-color: var(--surface-card);
}

.btn-block {
  width: 100%;
}

.btn-sm {
  padding: 6px 16px;
  font-size: 13px;
  height: 32px;
}

.btn-danger {
  background-color: var(--error);
  color: var(--on-primary);
}

.btn-danger:hover {
  background-color: #b33b3b;
}

.hidden {
  display: none !important;
}

.alert {
  padding: var(--s-md) var(--s-lg);
  border-radius: var(--r-md);
  margin-bottom: var(--s-md);
  font-size: 14px;
}

.alert-success {
  background-color: rgba(93, 184, 114, 0.1);
  color: var(--success);
  border: 1px solid var(--success);
}

.alert-error {
  background-color: rgba(198, 69, 69, 0.1);
  color: var(--error);
  border: 1px solid var(--error);
}

.flash-messages {
  margin-bottom: var(--s-md);
}

.theme-toggle {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--canvas);
  border: 1px solid var(--hairline);
  font-size: 16px;
  cursor: pointer;
  z-index: 1000;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ink);
}

.theme-toggle:hover {
  background-color: var(--surface-card);
}

@media (max-width: 768px) {
  h1 { font-size: 32px; }
  h2 { font-size: 28px; }
  h3 { font-size: 22px; }

  .header-content {
    padding: 0 var(--s-md);
  }

  .logo-icon {
    width: 28px;
    height: 28px;
  }

  .logo-cn {
    font-size: 18px;
  }

  .logo-en {
    display: none;
  }

  .model-select {
    min-width: 80px;
    font-size: 12px;
    padding: 6px 10px;
  }

  .header-button {
    padding: 6px 12px;
    font-size: 12px;
  }

  .user-name {
    display: none;
  }
}