/* era-ui.css - ERA Design System v1
   Foundation: variables, typography, components
   Inspired by Linear, Stripe, Vercel, Anthropic design quality
*/

/* ========== DESIGN TOKENS ========== */
:root {
  /* Brand colors */
  --era-burn: #FF4F00;
  --era-burn-dark: #DC5000;
  --era-burn-light: #FF7040;
  --era-burn-soft: #FFB088;
  --era-burn-bg: #FFF5F0;

  /* Ink (text) */
  --era-ink: #0F0F12;
  --era-ink-soft: #4B5563;
  --era-ink-muted: #6B7280;
  --era-ink-subtle: #9CA3AF;

  /* Surface */
  --era-bg: #FAFAF7;
  --era-surface: #FFFFFF;
  --era-surface-2: #F5F4EF;
  --era-border: rgba(0, 0, 0, 0.08);
  --era-border-strong: rgba(0, 0, 0, 0.15);

  /* Dark surfaces */
  --era-dark: #08080A;
  --era-dark-surface: #0F0F14;
  --era-dark-surface-2: #15151A;
  --era-dark-border: #1A1A1F;
  --era-dark-text: #E8E8EE;
  --era-dark-text-soft: #8A8A94;
  --era-dark-text-muted: #6E6E78;

  /* Status */
  --era-success: #10B981;
  --era-success-soft: #6EE7B7;
  --era-success-bg: rgba(16, 185, 129, 0.1);
  --era-warning: #F59E0B;
  --era-warning-soft: #FBBF24;
  --era-warning-bg: rgba(245, 158, 11, 0.1);
  --era-danger: #EF4444;
  --era-danger-soft: #FCA5A5;
  --era-danger-bg: rgba(239, 68, 68, 0.1);
  --era-info: #60A5FA;
  --era-info-soft: #93C5FD;
  --era-info-bg: rgba(96, 165, 250, 0.1);

  /* Shadows - layered, sophisticated */
  --era-shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.04);
  --era-shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.08), 0 1px 2px 0 rgba(0, 0, 0, 0.04);
  --era-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --era-shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
  --era-shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --era-shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
  --era-shadow-glow: 0 0 0 4px rgba(255, 79, 0, 0.15);

  /* Radius */
  --era-r-xs: 4px;
  --era-r-sm: 6px;
  --era-r-md: 8px;
  --era-r-lg: 12px;
  --era-r-xl: 16px;
  --era-r-2xl: 20px;
  --era-r-full: 9999px;

  /* Transitions */
  --era-transition: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --era-transition-slow: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --era-spring: 350ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Fluid typography */
  --era-text-xs: clamp(11px, 0.75vw + 0.5rem, 12px);
  --era-text-sm: clamp(12px, 0.85vw + 0.5rem, 13px);
  --era-text-base: clamp(14px, 1vw + 0.5rem, 15px);
  --era-text-lg: clamp(16px, 1.2vw + 0.5rem, 18px);
  --era-text-xl: clamp(18px, 1.5vw + 0.5rem, 22px);
  --era-text-2xl: clamp(22px, 2vw + 0.5rem, 28px);
  --era-text-3xl: clamp(28px, 2.8vw + 0.5rem, 36px);
  --era-text-4xl: clamp(36px, 4vw + 0.5rem, 52px);
  --era-text-5xl: clamp(48px, 5.5vw + 0.5rem, 76px);
  --era-text-6xl: clamp(60px, 7vw + 0.5rem, 96px);

  /* Spacing scale */
  --era-space-0: 0;
  --era-space-1: 4px;
  --era-space-2: 8px;
  --era-space-3: 12px;
  --era-space-4: 16px;
  --era-space-5: 20px;
  --era-space-6: 24px;
  --era-space-8: 32px;
  --era-space-10: 40px;
  --era-space-12: 48px;
  --era-space-16: 64px;
  --era-space-20: 80px;
  --era-space-24: 96px;
}

/* ========== TYPOGRAPHY ========== */

.era-h1 {
  font-size: var(--era-text-5xl);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--era-ink);
}
.era-h2 {
  font-size: var(--era-text-4xl);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.025em;
  color: var(--era-ink);
}
.era-h3 {
  font-size: var(--era-text-3xl);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--era-ink);
}
.era-h4 {
  font-size: var(--era-text-2xl);
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.015em;
  color: var(--era-ink);
}
.era-lead {
  font-size: var(--era-text-lg);
  line-height: 1.6;
  color: var(--era-ink-soft);
  font-weight: 400;
}
.era-body { font-size: var(--era-text-base); line-height: 1.6; color: var(--era-ink-soft); }
.era-small { font-size: var(--era-text-sm); color: var(--era-ink-muted); }
.era-label {
  font-size: var(--era-text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--era-ink-muted);
}

/* Gradient text */
.era-text-gradient {
  background: linear-gradient(135deg, var(--era-ink) 30%, var(--era-burn) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ========== BUTTONS ========== */

.era-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border: 1px solid transparent;
  border-radius: var(--era-r-md);
  padding: 10px 16px;
  font-size: var(--era-text-sm);
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--era-transition);
  position: relative;
  user-select: none;
  white-space: nowrap;
}
.era-btn:focus-visible { outline: 2px solid var(--era-burn); outline-offset: 2px; }
.era-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.era-btn-primary {
  background: var(--era-burn);
  color: white;
  box-shadow: var(--era-shadow-sm);
}
.era-btn-primary:hover {
  background: var(--era-burn-dark);
  transform: translateY(-1px);
  box-shadow: var(--era-shadow-md);
}
.era-btn-primary:active { transform: translateY(0); box-shadow: var(--era-shadow-sm); }

.era-btn-secondary {
  background: var(--era-surface);
  color: var(--era-ink);
  border-color: var(--era-border-strong);
}
.era-btn-secondary:hover {
  background: var(--era-surface-2);
  border-color: var(--era-ink-soft);
}

.era-btn-ghost {
  background: transparent;
  color: var(--era-ink-soft);
}
.era-btn-ghost:hover {
  background: var(--era-surface-2);
  color: var(--era-ink);
}

.era-btn-glass {
  background: rgba(255, 255, 255, 0.08);
  color: white;
  border-color: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.era-btn-glass:hover { background: rgba(255, 255, 255, 0.12); }

.era-btn-danger { background: var(--era-danger); color: white; }
.era-btn-danger:hover { background: #DC2626; }

.era-btn-lg { padding: 13px 24px; font-size: var(--era-text-base); border-radius: var(--era-r-lg); }
.era-btn-sm { padding: 6px 12px; font-size: var(--era-text-xs); }
.era-btn-icon { padding: 8px; width: 36px; height: 36px; }

/* ========== CARDS ========== */

.era-card {
  background: var(--era-surface);
  border: 1px solid var(--era-border);
  border-radius: var(--era-r-lg);
  padding: var(--era-space-6);
  transition: all var(--era-transition-slow);
}
.era-card-interactive {
  cursor: pointer;
}
.era-card-interactive:hover {
  transform: translateY(-2px);
  border-color: var(--era-burn);
  box-shadow: var(--era-shadow-lg);
}

.era-card-dark {
  background: var(--era-dark-surface);
  border-color: var(--era-dark-border);
  color: var(--era-dark-text);
}

/* ========== INPUTS ========== */

.era-input,
.era-textarea,
.era-select {
  width: 100%;
  padding: 10px 14px;
  font-size: var(--era-text-sm);
  font-family: inherit;
  background: var(--era-surface);
  border: 1px solid var(--era-border-strong);
  border-radius: var(--era-r-md);
  color: var(--era-ink);
  transition: all var(--era-transition);
  outline: none;
}
.era-input:focus,
.era-textarea:focus,
.era-select:focus {
  border-color: var(--era-burn);
  box-shadow: var(--era-shadow-glow);
}
.era-textarea { resize: vertical; min-height: 90px; }

.era-input-dark {
  background: var(--era-dark-surface-2);
  border-color: var(--era-dark-border);
  color: var(--era-dark-text);
}
.era-input-dark:focus { border-color: var(--era-burn); }

/* Field with floating label */
.era-field {
  position: relative;
  margin-bottom: var(--era-space-4);
}
.era-field-label {
  display: block;
  font-size: var(--era-text-xs);
  font-weight: 600;
  color: var(--era-ink-muted);
  margin-bottom: 6px;
  letter-spacing: 0.05em;
}
.era-field-hint { font-size: var(--era-text-xs); color: var(--era-ink-subtle); margin-top: 4px; }
.era-field-error { font-size: var(--era-text-xs); color: var(--era-danger); margin-top: 4px; }

/* ========== BADGES ========== */

.era-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 9px;
  font-size: 11px;
  font-weight: 600;
  border-radius: var(--era-r-full);
  letter-spacing: 0.02em;
}
.era-badge-success { background: var(--era-success-bg); color: var(--era-success); }
.era-badge-warning { background: var(--era-warning-bg); color: var(--era-warning); }
.era-badge-danger { background: var(--era-danger-bg); color: var(--era-danger); }
.era-badge-info { background: var(--era-info-bg); color: var(--era-info); }
.era-badge-neutral { background: rgba(0,0,0,0.06); color: var(--era-ink-soft); }
.era-badge-brand { background: rgba(255, 79, 0, 0.1); color: var(--era-burn); }

/* ========== LOADING STATES ========== */

@keyframes era-shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}
.era-skeleton {
  background: linear-gradient(90deg, var(--era-surface-2) 0%, rgba(0,0,0,0.04) 50%, var(--era-surface-2) 100%);
  background-size: 200% 100%;
  animation: era-shimmer 1.5s infinite;
  border-radius: var(--era-r-sm);
}
.era-skeleton-dark {
  background: linear-gradient(90deg, var(--era-dark-surface-2) 0%, var(--era-dark-border) 50%, var(--era-dark-surface-2) 100%);
  background-size: 200% 100%;
  animation: era-shimmer 1.5s infinite;
  border-radius: var(--era-r-sm);
}

@keyframes era-spin { to { transform: rotate(360deg); } }
.era-spinner {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: era-spin 0.7s linear infinite;
}

/* ========== ANIMATIONS ========== */

@keyframes era-fade-in { from { opacity: 0; } to { opacity: 1; } }
@keyframes era-slide-up { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes era-slide-down { from { opacity: 0; transform: translateY(-20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes era-scale-in { from { opacity: 0; transform: scale(0.95); } to { opacity: 1; transform: scale(1); } }

.era-fade-in { animation: era-fade-in 0.4s ease-out; }
.era-slide-up { animation: era-slide-up 0.5s cubic-bezier(0.16, 1, 0.3, 1); }
.era-scale-in { animation: era-scale-in 0.3s cubic-bezier(0.34, 1.56, 0.64, 1); }

/* Scroll-triggered reveal */
.era-reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}
.era-reveal.era-revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ========== UTILITY ========== */

.era-container { max-width: 1200px; margin: 0 auto; padding: 0 var(--era-space-6); }
.era-container-sm { max-width: 760px; margin: 0 auto; padding: 0 var(--era-space-6); }
.era-container-lg { max-width: 1400px; margin: 0 auto; padding: 0 var(--era-space-6); }

.era-stack { display: flex; flex-direction: column; gap: var(--era-space-4); }
.era-row { display: flex; align-items: center; gap: var(--era-space-3); flex-wrap: wrap; }
.era-spread { display: flex; align-items: center; justify-content: space-between; gap: var(--era-space-3); }

/* ========== EMPTY STATES ========== */

.era-empty {
  text-align: center;
  padding: var(--era-space-16) var(--era-space-6);
}
.era-empty-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--era-space-4);
  color: var(--era-ink-subtle);
  opacity: 0.5;
}
.era-empty-title {
  font-size: var(--era-text-lg);
  font-weight: 600;
  color: var(--era-ink);
  margin-bottom: var(--era-space-2);
}
.era-empty-body {
  font-size: var(--era-text-sm);
  color: var(--era-ink-muted);
  max-width: 360px;
  margin: 0 auto var(--era-space-5);
  line-height: 1.6;
}

/* ========== ACCESSIBILITY ========== */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus rings for keyboard users only */
:focus:not(:focus-visible) { outline: none; }
:focus-visible { outline: 2px solid var(--era-burn); outline-offset: 2px; border-radius: var(--era-r-sm); }