/* ===== RESET & BASE ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg-primary: #09090b;
  --bg-secondary: #111113;
  --bg-card: #18181b;
  --bg-input: #1e1e22;
  --bg-hover: #27272a;
  --border: #2e2e33;
  --border-focus: #E04F1A;
  --text-primary: #fafafa;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --accent: #E04F1A;
  --accent-hover: #FF8C42;
  --accent-glow: rgba(224, 79, 26, 0.15);
  --success: #22c55e;
  --danger: #ef4444;
  --warning: #f59e0b;
  --gradient: linear-gradient(135deg, #E04F1A, #FF8C42, #FFB347);

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --transition: 150ms cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===== ACCESSIBILITY ===== */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  background: var(--accent);
  color: #fff;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  z-index: 9999;
  font-weight: 600;
  text-decoration: none;
  transition: top var(--transition);
}

.skip-link:focus {
  top: 1rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ===== LAYOUT ===== */
.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1rem;
}

@media (min-width: 768px) {
  .container {
    padding: 0 2rem;
  }
}

/* ===== HEADER ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(9, 9, 11, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 0.875rem 0;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-icon {
  display: flex;
  align-items: center;
}

.logo-text {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.nav-links {
  display: none;
  list-style: none;
  gap: 0.25rem;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}

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

.btn-donate {
  background: var(--gradient) !important;
  color: #fff !important;
  padding: 0.5rem 1rem !important;
  border-radius: var(--radius-sm) !important;
  font-weight: 600 !important;
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
  }
  .mobile-menu-btn {
    display: none;
  }
}

/* Mobile Menu Button */
.mobile-menu-btn {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: var(--radius-sm);
}

@media (min-width: 768px) {
  .mobile-menu-btn {
    display: none;
  }
}

.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 2px;
  transition: var(--transition);
}

.mobile-menu-btn[aria-expanded="true"] span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.mobile-menu-btn[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.mobile-menu-btn[aria-expanded="true"] span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Nav */
.mobile-nav {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: 1rem;
}

.mobile-nav[hidden] {
  display: none;
}

.mobile-nav ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.mobile-nav a {
  display: block;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 1rem;
  font-weight: 500;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.mobile-nav a:hover {
  color: var(--text-primary);
  background: var(--bg-hover);
}

@media (min-width: 768px) {
  .mobile-nav {
    display: none !important;
  }
}

/* ===== HERO ===== */
.hero {
  padding: 4rem 0 3rem;
  text-align: center;
}

.hero h1 {
  font-size: clamp(2rem, 6vw, 3.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 1rem;
}

.gradient-text {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  color: var(--text-secondary);
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  max-width: 650px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ===== BUILDER ===== */
.builder-section {
  padding: 2rem 0 4rem;
}

.section-title {
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
  text-align: center;
}

/* Tabs */
.tabs {
  display: flex;
  gap: 0;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.tab {
  flex: 1;
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.875rem 1.25rem;
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-sans);
  text-align: center;
}

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

.tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

@media (min-width: 768px) {
  .tab {
    flex: none;
    font-size: 0.95rem;
    padding: 0.875rem 1.75rem;
  }
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
  animation: fadeIn 200ms ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.builder-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  box-shadow: 0 4px 40px rgba(0, 0, 0, 0.3);
}

@media (min-width: 768px) {
  .builder-card {
    padding: 2rem;
  }
}

.subsection-title {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

/* Rule Chips */
.rule-type-selector {
  margin-bottom: 1.5rem;
}

.rule-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-weight: 500;
  padding: 0.5rem 0.875rem;
  border-radius: 100px;
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-sans);
}

.chip:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
}

.chip.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* Rule Config Panel */
.rule-config {
  background: var(--bg-input);
  border: 1px solid var(--border-focus);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin-bottom: 1.5rem;
  animation: slideIn 200ms ease-out;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

.rule-config[hidden] {
  display: none;
}

.rule-config-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.rule-config-fields {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.field-group {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.field-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.select-input,
.text-input {
  width: 100%;
  padding: 0.625rem 0.875rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.875rem;
  font-family: var(--font-sans);
  transition: border-color var(--transition), box-shadow var(--transition);
  appearance: none;
  -webkit-appearance: none;
}

.select-input {
  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='%2371717a' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2rem;
}

.select-input:focus,
.text-input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
  outline: none;
}

.textarea-input {
  width: 100%;
  padding: 0.875rem;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-family: var(--font-mono);
  line-height: 1.6;
  resize: vertical;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.textarea-input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
  outline: none;
}

/* Buttons */
.btn-primary-sm {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--accent);
  border: none;
  color: #fff;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-sans);
}

.btn-primary-sm:hover {
  background: var(--accent-hover);
}

.btn-primary-sm:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-ghost-sm {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 500;
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-sans);
}

.btn-ghost-sm:hover {
  border-color: var(--danger);
  color: var(--danger);
}

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

.btn-action {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  font-family: var(--font-sans);
}

.btn-action:hover {
  border-color: var(--accent);
  color: var(--accent);
}

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

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

/* Active Rules */
.active-rules {
  margin-bottom: 1.5rem;
}

.active-rules-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  background: var(--accent-glow);
  color: var(--accent);
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0 0.4rem;
  border-radius: 100px;
  margin-left: 0.5rem;
}

.rules-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.empty-state {
  text-align: center;
  padding: 2rem 1rem;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.rule-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  animation: slideIn 200ms ease-out;
}

.rule-item-info {
  flex: 1;
  min-width: 0;
}

.rule-item-type {
  font-size: 0.7rem;
  color: var(--accent);
  text-transform: uppercase;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.rule-item-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.rule-item-actions {
  display: flex;
  gap: 0.25rem;
}

.btn-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition);
}

.btn-icon:hover {
  border-color: var(--danger);
  color: var(--danger);
}

/* Output Section */
.output-section {
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.output-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.output-actions {
  display: flex;
  gap: 0.5rem;
}

.output-code {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1rem 1.25rem;
  min-height: 80px;
  overflow-x: auto;
}

.output-code pre {
  margin: 0;
}

.output-code code {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-hover);
  line-height: 1.7;
  white-space: pre-wrap;
  word-break: break-all;
}

.output-code code.empty {
  color: var(--text-muted);
}

/* ===== IMPORT (inside tab) ===== */
.import-description {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.import-field {
  margin-bottom: 1rem;
}

.import-feedback {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
}

.import-feedback.success {
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid var(--success);
  color: var(--success);
}

.import-feedback.error {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid var(--danger);
  color: var(--danger);
}

/* ===== HOW IT WORKS ===== */
.how-section {
  padding: 4rem 0;
}

.steps-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 640px) {
  .steps-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .steps-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.step-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: border-color var(--transition), transform var(--transition);
}

.step-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--accent-glow);
  color: var(--accent);
  font-weight: 700;
  font-size: 1.1rem;
  border-radius: 50%;
  margin-bottom: 1rem;
}

.step-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.step-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ===== REFERENCE ===== */
.reference-section {
  padding: 2rem 0 4rem;
}

.reference-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 768px) {
  .reference-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.ref-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.ref-card h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--accent-hover);
}

.ref-card ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.ref-card li {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.ref-card code {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  background: var(--bg-input);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  color: var(--accent-hover);
}

/* ===== FOOTER ===== */
.footer {
  border-top: 1px solid var(--border);
  padding: 2.5rem 0;
  text-align: center;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 1rem;
}

.footer-text {
  color: var(--text-muted);
  font-size: 0.85rem;
  max-width: 500px;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  transition: color var(--transition);
}

.footer-links a:hover {
  color: var(--accent);
}

.footer-copy {
  color: var(--text-muted);
  font-size: 0.75rem;
  margin-top: 0.5rem;
}

/* ===== REDUCED MOTION ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html {
    scroll-behavior: auto;
  }
}

/* ===== HIGH CONTRAST ===== */
@media (prefers-contrast: high) {
  :root {
    --border: #555;
    --text-secondary: #ccc;
    --text-muted: #aaa;
  }
}

/* ===== HERO COUNTER ===== */
.hero-counter {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  margin-top: 1.5rem;
  padding: 0.6rem 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 100px;
}

.counter-number {
  font-size: 1.25rem;
  font-weight: 700;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.counter-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
}