/* ============================================
   Design Kit — CSS Variables & Component Styles
   Mobile-first UI Kit based on app design system
   ============================================ */

/* --- Design Tokens (CSS Custom Properties) --- */
:root {
  /* Colors */
  --color-bg: #FFFFFF;
  --color-bg-blocks: #F2F2F7;
  --color-bg-input: #F6F6F6;
  --color-text: #00000C;
  --color-text-secondary: rgba(0, 0, 12, 0.6);
  --color-text-tertiary: rgba(0, 0, 12, 0.4);
  --color-accent: #5376FF;
  --color-accent-hover: #4563e6;
  --color-accent-press: #3d59cc;
  --color-accent-inactive: rgba(83, 118, 255, 0.5);

  /* Typography */
  --font-family: 'Google Sans Flex', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-xs: 0.75rem;    /* 12px */
  --font-size-sm: 0.875rem;   /* 14px */
  --font-size-base: 1rem;     /* 16px */
  --font-size-lg: 1.125rem;   /* 18px */
  --font-size-xl: 1.25rem;   /* 20px */
  --font-size-2xl: 1.5rem;   /* 24px */
  --font-size-3xl: 2rem;     /* 32px */
  --font-size-4xl: 2.25rem;  /* 36px */
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --line-height-tight: 1.2;
  --line-height-normal: 1.4;
  --line-height-relaxed: 1.6;

  /* Spacing */
  --space-xs: 0.25rem;   /* 4px */
  --space-sm: 0.5rem;    /* 8px */
  --space-md: 1rem;      /* 16px */
  --space-lg: 1.5rem;    /* 24px */
  --space-xl: 2rem;      /* 32px */
  --space-2xl: 2.5rem;   /* 40px */
  --space-3xl: 3rem;     /* 48px */

  /* Border Radius */
  --radius-button: 99px;
  --radius-card: 14px;
  --radius-input: 14px;
  --radius-badge: 8px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 12, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 12, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 12, 0.12);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

/* --- Base Styles --- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-regular);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Typography --- */
h1, h2, h3, h4 {
  margin: 0 0 var(--space-md);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }

p {
  margin: 0 0 var(--space-md);
  color: var(--color-text-secondary);
}

.caption {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  margin: 0;
}

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

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  font-family: var(--font-family);
  font-weight: var(--font-weight-medium);
  border: none;
  border-radius: var(--radius-button);
  cursor: pointer;
  transition: background-color var(--transition-fast), opacity var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn svg {
  flex-shrink: 0;
  vertical-align: middle;
}

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

/* Primary */
.btn-primary {
  background-color: var(--color-accent);
  color: var(--color-bg);
}

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

.btn-primary:active:not(:disabled) {
  background-color: var(--color-accent-press);
}

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

/* Secondary */
.btn-secondary {
  background-color: var(--color-bg-blocks);
  color: var(--color-text);
}

.btn-secondary:hover:not(:disabled) {
  background-color: #e8e8ed;
}

.btn-secondary:active:not(:disabled) {
  background-color: #dedee5;
}

/* Outline */
.btn-outline {
  background-color: transparent;
  color: var(--color-accent);
  border: 1px solid var(--color-accent);
}

.btn-outline:hover:not(:disabled) {
  background-color: rgba(83, 118, 255, 0.08);
}

.btn-outline:active:not(:disabled) {
  background-color: rgba(83, 118, 255, 0.15);
}

/* Ghost / Text */
.btn-ghost {
  background-color: transparent;
  color: var(--color-text-secondary);
}

.btn-ghost:hover:not(:disabled) {
  color: var(--color-text);
  background-color: var(--color-bg-blocks);
}

/* Sizes */
.btn-sm {
  padding: var(--space-sm) var(--space-md);
  font-size: var(--font-size-sm);
}

.btn-md {
  padding: var(--space-md) var(--space-lg);
  font-size: var(--font-size-base);
}

.btn-lg {
  padding: var(--space-md) var(--space-xl);
  font-size: var(--font-size-lg);
}

.btn-full {
  width: 100%;
}

/* Icon button */
.btn-icon {
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: 50%;
}

.btn-icon.btn-sm {
  width: 36px;
  height: 36px;
}

/* --- Form Elements --- */
.form-group {
  margin-bottom: var(--space-lg);
}

.form-label {
  display: block;
  margin-bottom: var(--space-sm);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: var(--space-md);
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  color: var(--color-text);
  background-color: var(--color-bg-input);
  border: none;
  border-radius: var(--radius-input);
  transition: background-color var(--transition-fast), box-shadow var(--transition-fast);
}

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

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  background-color: #eeeeef;
  box-shadow: 0 0 0 2px var(--color-accent);
}

.form-input:disabled,
.form-select:disabled,
.form-textarea:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.form-textarea {
  min-height: 120px;
  resize: vertical;
}

.form-select {
  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='%2300000C' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-md) center;
  padding-right: 2.5rem;
}

/* Checkbox */
.form-checkbox {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  cursor: pointer;
}

.form-checkbox input {
  width: 20px;
  height: 20px;
  min-width: 20px;
  margin: 2px 0 0;
  accent-color: var(--color-accent);
  cursor: pointer;
}

.form-checkbox span {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

/* --- Cards --- */
.card {
  background-color: var(--color-bg);
  border-radius: var(--radius-card);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-normal);
}

.card-elevated {
  box-shadow: var(--shadow-md);
}

.card-interactive:hover {
  box-shadow: var(--shadow-md);
}

.card-header {
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-md);
  border-bottom: 1px dotted var(--color-text-tertiary);
}

.card-title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
  margin: 0;
}

.card-body {
  margin: 0;
}

/* --- Badges --- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-badge);
  white-space: nowrap;
}

.badge-default {
  background-color: var(--color-bg-blocks);
  color: var(--color-text-secondary);
  border: 1px solid rgba(0, 0, 12, 0.1);
}

.badge-success {
  background-color: rgba(34, 197, 94, 0.15);
  color: #15803d;
}

.badge-error {
  background-color: rgba(239, 68, 68, 0.15);
  color: #b91c1c;
}

.badge-warning {
  background-color: rgba(234, 179, 8, 0.2);
  color: #a16207;
}

.badge-accent {
  background-color: rgba(83, 118, 255, 0.15);
  color: var(--color-accent);
}

/* --- Icons (placeholder styles for icon usage) --- */
.icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.icon-sm {
  width: 20px;
  height: 20px;
}

.icon-lg {
  width: 32px;
  height: 32px;
}

/* Icon SVG stroke */
.icon svg {
  width: 100%;
  height: 100%;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* --- Segmented Control --- */
.segmented-control {
  display: inline-flex;
  background-color: var(--color-bg-blocks);
  border-radius: var(--radius-button);
  padding: var(--space-xs);
  gap: 0;
}

.segmented-control button {
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  background: transparent;
  border: none;
  border-radius: var(--radius-button);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.segmented-control button.active {
  background-color: var(--color-accent);
  color: var(--color-bg);
}

.segmented-control button:hover:not(.active) {
  color: var(--color-text);
}

/* --- Color Palette Display --- */
.color-swatch {
  width: 100%;
  min-height: 80px;
  border-radius: var(--radius-card);
  margin-bottom: var(--space-sm);
}

.color-swatch-label {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  margin: 0;
}

/* --- Section Headers for Showcase --- */
.showcase-section {
  margin-bottom: var(--space-3xl);
}

.showcase-section-title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0 0 var(--space-lg);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-bg-blocks);
}

.showcase-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  align-items: flex-start;
}

.showcase-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  align-items: center;
  margin-bottom: var(--space-md);
}