:root {
  color-scheme: light;

  --font-scale: 1;

  --color-primary: #256ef4;
  --color-primary-hover: #0b50d0;
  --color-primary-deep: #083891;
  --color-primary-surface: #ecf2fe;
  --color-primary-surface-hover: #dfe9fd;
  --color-canvas: #f4f5f6;
  --color-surface: #ffffff;
  --color-fg: #1e2124;
  --color-body: #464c53;
  --color-muted: #6d7882;
  --color-border-strong: #58616a;
  --color-border: #b1b8be;
  --color-hairline: #cdd1d5;
  --color-on-primary: #ffffff;
  --color-danger: #de3412;
  --color-warning: #ffb114;
  --color-warning-bg: #faeeda;
  --color-success: #228738;

  --space-xs: 2px;
  --space-sm: 4px;
  --space-md: 8px;
  --space-base: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-xxl: 40px;

  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-modal: 12px;
  --radius-full: 999px;

  --font-sans: Pretendard, -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Malgun Gothic", system-ui, sans-serif;
  --text-ui: 1.0625rem;
  --leading-ui: 1.5;

  --focus-ring: 0 0 0 4px #256ef459;
  --shadow-float: 0 2px 0 0 #0000001a, 0 4px 8px 0 #0000001a;

  --dur-fast: 0.12s;
  --dur-base: 0.2s;
  --ease-out: cubic-bezier(0.2, 0, 0, 1);

  --container: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: calc(16px * var(--font-scale));
}

:root[data-contrast="high"] {
  --color-primary: #0000cc;
  --color-primary-hover: #000099;
  --color-primary-deep: #000066;
  --color-primary-surface: #cce0ff;
  --color-primary-surface-hover: #b3d1ff;
  --color-canvas: #ffffff;
  --color-surface: #ffffff;
  --color-fg: #000000;
  --color-body: #000000;
  --color-muted: #1a1a1a;
  --color-border-strong: #000000;
  --color-border: #000000;
  --color-hairline: #000000;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--color-canvas);
  color: var(--color-body);
  font-family: var(--font-sans);
  font-size: var(--text-ui);
  line-height: var(--leading-ui);
  font-synthesis: none;
  -webkit-font-smoothing: antialiased;
}

/* ---------- site header / footer ---------- */

.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-hairline);
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-header-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: var(--space-base) var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.brand-block {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.brand-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-md);
  background: var(--color-primary-surface);
  font-size: 1.1rem;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
}

.brand-eyebrow {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-muted);
}

.brand-title {
  font-size: 1.1875rem;
  font-weight: 700;
  color: var(--color-fg);
}

.header-controls {
  display: flex;
  align-items: center;
  gap: var(--space-base);
  flex-wrap: wrap;
}

.font-size-control {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.8125rem;
  color: var(--color-muted);
  white-space: nowrap;
}

.font-size-control .icon-btn {
  width: 28px;
  height: 28px;
  padding: 0;
  margin-bottom: 0;
  font-size: 0.9375rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
}

#contrast-toggle {
  margin-bottom: 0;
}

#contrast-toggle[aria-pressed="true"] {
  background: var(--color-fg);
  color: var(--color-surface);
  border-color: var(--color-fg);
}

.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--color-hairline);
  padding: var(--space-lg);
  text-align: center;
  color: var(--color-muted);
  font-size: 0.875rem;
}

/* ---------- layout ---------- */

.login-wrap {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-xxl) var(--space-base);
}

.app-wrap {
  flex: 1;
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-base) 64px;
}

.page-intro {
  margin-bottom: var(--space-lg);
}

.page-intro h1 {
  margin: 0 0 var(--space-sm);
}

.page-intro .muted {
  margin: 0;
}

/* ---------- card (panel) ---------- */

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  margin-bottom: var(--space-lg);
}

.login-wrap .card {
  width: 100%;
  max-width: 440px;
  box-shadow: var(--shadow-float);
}

/* ---------- typography ---------- */

h1 {
  color: var(--color-fg);
  font-size: 1.375rem;
  font-weight: 500;
  margin: 0 0 var(--space-xs);
}

h2 {
  color: var(--color-primary-deep);
  font-size: 1.1875rem;
  font-weight: 500;
  margin: 0 0 var(--space-base);
}

.muted {
  color: var(--color-muted);
  font-size: 0.9375rem;
  margin: 0 0 var(--space-base);
}

/* ---------- form elements ---------- */

label {
  display: block;
  color: var(--color-fg);
  font-weight: 500;
  font-size: 0.9375rem;
  margin-bottom: var(--space-base);
}

label.checkbox-row {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 400;
  color: var(--color-muted);
}

label.checkbox-row input {
  width: auto;
  margin-top: 0;
}

input,
textarea {
  display: block;
  width: 100%;
  margin-top: var(--space-sm);
  padding: var(--space-md) 12px;
  font-family: inherit;
  font-size: var(--text-ui);
  color: var(--color-fg);
  background: var(--color-surface);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-lg);
  resize: vertical;
  transition: border-color var(--dur-fast) var(--ease-out);
}

input::placeholder,
textarea::placeholder {
  color: var(--color-muted);
}

input:focus-visible,
textarea:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
  border-color: var(--color-primary);
}

textarea[readonly] {
  background: var(--color-canvas);
}

.hint {
  display: block;
  font-weight: 400;
  color: var(--color-muted);
  font-size: 0.8125rem;
  margin-top: var(--space-xs);
}

.status {
  min-height: 1.2em;
  font-size: 0.9375rem;
  color: var(--color-danger);
}

/* ---------- buttons ---------- */

button {
  font-family: inherit;
  font-weight: 500;
  font-size: 0.9375rem;
  height: 44px;
  padding: 0 var(--space-lg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-primary);
  background: var(--color-primary);
  color: var(--color-on-primary);
  cursor: pointer;
  margin-bottom: var(--space-base);
  transition: background var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out);
}

button:hover:not(:disabled) {
  background: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
}

button:active:not(:disabled) {
  background: var(--color-primary-deep);
}

button:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

button.secondary {
  background: transparent;
  color: var(--color-fg);
  border-color: var(--color-border-strong);
}

button.secondary:hover:not(:disabled) {
  background: var(--color-canvas);
}

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

/* ---------- accordion ---------- */

details.card {
  padding: 0;
}

details.card > summary {
  cursor: pointer;
  color: var(--color-primary-deep);
  font-weight: 500;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding: var(--space-base) var(--space-xl);
}

details.card > summary::-webkit-details-marker {
  display: none;
}

details.card > summary::after {
  content: "";
  width: 8px;
  height: 8px;
  flex-shrink: 0;
  border-right: 2px solid var(--color-muted);
  border-bottom: 2px solid var(--color-muted);
  transform: rotate(45deg);
  transition: transform var(--dur-base) var(--ease-out);
}

details.card[open] > summary::after {
  transform: rotate(-135deg);
}

details.card[open] > summary {
  border-bottom: 1px solid var(--color-hairline);
}

details.card > .accordion-body {
  padding: var(--space-base) var(--space-xl) var(--space-xl);
}

details.card > .accordion-body > label {
  margin-top: 0;
}

/* ---------- AI 설정 panel ---------- */

.field-block {
  margin-bottom: var(--space-lg);
}

.field-block-label {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 500;
  color: var(--color-fg);
  font-size: 0.9375rem;
  margin-bottom: var(--space-sm);
}

.pill-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.pill,
.provider-tab {
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  height: auto;
  padding: var(--space-sm) var(--space-base);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border-strong);
  background: var(--color-surface);
  color: var(--color-body);
  cursor: pointer;
  margin-bottom: 0;
  transition: background var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}

.pill:hover:not(:disabled),
.provider-tab:hover:not(:disabled) {
  background: var(--color-canvas);
}

.pill.active,
.provider-tab.active {
  border-color: var(--color-primary);
  background: var(--color-primary-surface);
  color: var(--color-primary-deep);
  font-weight: 700;
}

.provider-tab:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.api-key-panel {
  background: var(--color-canvas);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}

.api-key-panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  margin-bottom: var(--space-base);
  flex-wrap: wrap;
}

.link-action {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-primary);
  text-decoration: underline;
}

.provider-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-base);
}

.usage-stats {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-sm) var(--space-base);
  font-size: 0.8125rem;
  color: var(--color-muted);
  margin-bottom: var(--space-base);
}

.usage-stats .icon-btn {
  margin-bottom: 0;
}

.api-key-field {
  align-items: center;
  gap: var(--space-sm);
  padding: 0 var(--space-base);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  display: flex;
}

.api-key-field input {
  border: none;
  padding: var(--space-md) 0;
  margin-top: 0;
  flex: 1;
  min-width: 0;
}

.api-key-field input:focus-visible {
  box-shadow: none;
}

.api-key-field button {
  flex-shrink: 0;
  margin-bottom: 0;
}

.api-key-field #api-key-save {
  height: 36px;
  padding: 0 var(--space-base);
}

.icon-btn {
  width: 32px;
  height: 32px;
  padding: 0;
  font-size: 1rem;
  border-radius: var(--radius-sm);
}

/* ---------- responsive ---------- */

@media (max-width: 640px) {
  .site-header-inner {
    padding: var(--space-md) var(--space-base);
  }

  .app-wrap {
    padding: var(--space-base) 12px 48px;
  }

  .login-wrap {
    padding: var(--space-lg) 12px;
  }

  .card {
    padding: var(--space-lg);
    border-radius: var(--radius-md);
  }

  button {
    width: 100%;
  }

  .site-header-inner button,
  .pill,
  .provider-tab,
  .api-key-field button {
    width: auto;
  }

  .api-key-field {
    flex-wrap: wrap;
    padding: var(--space-sm) var(--space-base);
  }

  .api-key-field input {
    width: 100%;
    order: -1;
  }
}