/* Hallmark · genre: modern-minimal · theme: Coral · macrostructure: Marquee Hero
 * nav: N5 · footer: Ft2 · enrichment: none (typography only)
 * designed-as-app · design-system: design.md
 */

/* ============ Google Fonts Import ============ */
@import url('https://fonts.googleapis.com/css2?family=Geist:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ============ Base Reset ============ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  overflow-x: clip;
}

body {
  background: var(--color-paper);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-feature-settings: "ss01" on, "cv11" on;
  font-variant-numeric: tabular-nums;
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.hidden { display: none !important; }

/* ============ Focus Ring ============ */
:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

/* ============ Selection ============ */
::selection {
  background: oklch(65% 0.18 30 / 0.15);
}

/* ============ Scrollbar ============ */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--color-ink-2);
  border-radius: var(--radius-pill);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-ink);
}

/* ============ Navigation (N5 - Floating Pill) ============ */
.nav-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: var(--space-md) var(--page-gutter);
  background: oklch(98% 0.004 60 / 0.8);
  backdrop-filter: blur(12px);
}

.nav-container {
  max-width: var(--page-max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  cursor: pointer;
  transition: opacity var(--dur-short);
}

.nav-logo:hover {
  opacity: 0.7;
}

.nav-logo-icon-img {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 6px;
  object-fit: contain;
}

.nav-logo-text {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--color-ink);
}

.nav-pill {
  display: flex;
  align-items: center;
  gap: 2px;
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-pill);
  padding: 3px;
}

.nav-btn {
  position: relative;
  padding: 0.375rem 0.875rem;
  background: transparent;
  border: none;
  color: var(--color-ink-2);
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 500;
  cursor: pointer;
  transition: color var(--dur-short), background var(--dur-short);
  border-radius: var(--radius-pill);
}

.nav-btn:hover {
  color: var(--color-ink);
}

.nav-btn.active {
  color: var(--color-ink);
  background: var(--color-paper);
  box-shadow: var(--shadow-sm);
}

.nav-btn-text {
  position: relative;
  z-index: 1;
}

.nav-user-btn {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.875rem;
  border-radius: var(--radius-pill);
  background: var(--color-ink);
  border: none;
  cursor: pointer;
  transition: opacity var(--dur-short);
  color: var(--color-paper);
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.8125rem;
}

.nav-user-btn:hover {
  opacity: 0.85;
}

.nav-user-btn span:first-child {
  font-size: 0.875rem;
}

/* ============ User Dropdown ============ */
.user-dropdown-container {
  position: relative;
}

.user-dropdown {
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  width: 17rem;
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-lg);
  z-index: 1001;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: all var(--dur-medium) var(--ease-out);
}

.user-dropdown.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.user-dropdown-header {
  padding: 1rem;
  border-bottom: 1px solid var(--color-rule);
}

.user-dropdown-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.user-dropdown-avatar {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-input);
  background: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.875rem;
  font-weight: 600;
  color: white;
  flex-shrink: 0;
}

.user-dropdown-user {
  flex: 1;
  min-width: 0;
}

.user-dropdown-name {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 0.125rem;
}

.user-dropdown-email {
  font-size: 0.75rem;
  color: var(--color-ink-2);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.user-dropdown-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--color-rule);
}

.user-dropdown-stat {
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-input);
  padding: 0.625rem;
  text-align: center;
  transition: background var(--dur-short);
}

.user-dropdown-stat:hover {
  background: var(--color-paper-3);
}

.user-dropdown-stat-value {
  font-family: var(--font-label);
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-ink);
  margin-bottom: 0.125rem;
}

.user-dropdown-stat-label {
  font-family: var(--font-label);
  font-size: 0.625rem;
  color: var(--color-ink-2);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.user-dropdown-menu {
  padding: 0.375rem;
}

.user-dropdown-item {
  padding: 0.5rem 0.625rem;
  display: flex;
  align-items: center;
  gap: 0.625rem;
  color: var(--color-ink-2);
  font-size: 0.8125rem;
  font-weight: 500;
  transition: background var(--dur-short), color var(--dur-short);
  cursor: pointer;
  border-radius: var(--radius-input);
}

.user-dropdown-item:hover {
  background: var(--color-paper-2);
  color: var(--color-ink);
}

.user-dropdown-item-icon {
  font-size: 0.875rem;
  width: 1.125rem;
  text-align: center;
  flex-shrink: 0;
}

.user-dropdown-item-label {
  flex: 1;
}

.user-dropdown-divider {
  height: 1px;
  background: var(--color-rule);
  margin: 0.25rem 0.5rem;
}

.user-dropdown-logout {
  color: var(--color-accent);
}

.user-dropdown-logout:hover {
  background: oklch(65% 0.18 30 / 0.08);
  color: var(--color-accent);
}

/* ============ Main Container ============ */
.main-container {
  max-width: var(--page-max);
  margin: 0 auto;
  padding: var(--space-lg) var(--page-gutter) var(--space-3xl);
  position: relative;
  z-index: 50;
}

/* ============ Hero Section ============ */
.hero-section {
  padding: var(--space-xl) 0 var(--space-2xl);
  max-width: fit-content;
  margin: 0 auto;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.25rem 0.625rem;
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-pill);
  font-family: var(--font-label);
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--color-ink-2);
  margin-bottom: var(--space-lg);
  letter-spacing: 0.02em;
}

.hero-title {
  font-family: var(--font-display);
  font-size: var(--text-display);
  font-weight: 600;
  letter-spacing: -0.025em;
  margin-bottom: var(--space-md);
  line-height: 1.1;
  color: var(--color-ink);
  white-space: nowrap;
}

.hero-subtitle {
  font-size: var(--text-lg);
  color: var(--color-ink-2);
  margin-bottom: var(--space-xl);
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: var(--space-sm);
  justify-content: center;
  flex-wrap: wrap;
}

/* ============ Button System ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5em;
  padding: 0.625rem 1.25rem;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.875rem;
  border: none;
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: opacity var(--dur-short), background var(--dur-short);
}

.btn:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.btn[disabled] {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.btn-primary {
  background: var(--color-ink);
  color: var(--color-paper);
  padding: 0.75rem 2rem;
  font-size: var(--text-md);
}

.btn-primary:hover {
  opacity: 0.85;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background: transparent;
  color: var(--color-ink);
  border: 1.5px solid var(--color-ink);
  padding: 0.75rem 2rem;
  font-size: var(--text-md);
}

.btn-secondary:hover {
  background: var(--color-ink);
  color: var(--color-paper);
}

.btn-outline {
  background: transparent;
  color: var(--color-ink);
  border: 1px solid var(--color-rule);
}

.btn-outline:hover {
  background: var(--color-paper-2);
}

.btn-sm {
  padding: 0.375rem 0.875rem;
  font-size: var(--text-sm);
}

.btn-lg {
  padding: 0.75rem 1.5rem;
  font-size: var(--text-md);
}

/* ============ Cards ============ */
.card {
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-card);
  transition: box-shadow var(--dur-medium);
}

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

/* ============ Glass Card ============ */
.glass-card {
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-card);
  padding: var(--space-lg);
  transition: box-shadow var(--dur-medium);
}

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

/* ============ Stats Grid ============ */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-md);
  margin-bottom: var(--space-2xl);
}

.stat-card {
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-card);
  padding: var(--space-lg);
  transition: box-shadow var(--dur-medium);
}

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

.stat-icon-wrapper {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.stat-icon {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-input);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.125rem;
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  flex-shrink: 0;
}

.stat-label {
  font-family: var(--font-label);
  font-size: 0.9375rem;
  color: var(--color-ink-2);
  margin-bottom: 0.25rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.stat-value {
  font-family: var(--font-label);
  font-size: var(--text-2xl);
  font-weight: 500;
  color: var(--color-ink);
  line-height: 1;
}

/* ============ Wordbank Grid ============ */
.wordbank-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-sm);
}

.wordbank-card {
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-card);
  padding: var(--space-md);
  cursor: pointer;
  transition: box-shadow var(--dur-medium), border-color var(--dur-medium);
}

.wordbank-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-ink-2);
}

.wordbank-card.selected {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 1px var(--color-accent);
}

.wordbank-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.wordbank-icon {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-input);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.125rem;
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  transition: transform var(--dur-medium);
}

.wordbank-card:hover .wordbank-icon {
  transform: scale(1.05);
}

.wordbank-info { flex: 1; }

.wordbank-name {
  font-weight: 600;
  margin-bottom: 0.125rem;
  font-size: var(--text-md);
  color: var(--color-ink);
}

.wordbank-desc {
  font-size: var(--text-sm);
  color: var(--color-ink-2);
}

.wordbank-count {
  font-family: var(--font-label);
  font-size: var(--text-xs);
  color: var(--color-ink-2);
  margin-top: var(--space-sm);
  letter-spacing: 0.02em;
}

/* ============ Word Card ============ */
.word-card-container {
  perspective: 1000px;
  margin: var(--space-2xl) 0;
  position: relative;
  z-index: 1;
}

.word-card {
  width: 100%;
  height: 18rem;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.5s var(--ease-out);
  cursor: pointer;
  z-index: 1;
}

.word-card.flipped {
  transform: rotateY(180deg);
}

.word-card-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border-radius: var(--radius-card);
  padding: var(--space-2xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-rule);
  background: var(--color-paper);
}

.word-card-back {
  background: var(--color-paper-2);
  transform: rotateY(180deg);
  color: var(--color-ink);
  border-color: var(--color-accent);
}

.word-text {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

.word-pronunciation {
  font-family: var(--font-label);
  font-size: var(--text-md);
  color: var(--color-ink-2);
  margin-bottom: var(--space-md);
}

.word-meaning {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: var(--space-sm);
}

.word-example {
  font-size: var(--text-sm);
  color: var(--color-ink-2);
  text-align: center;
  line-height: 1.6;
  max-width: 80%;
}

/* ============ Progress Bar ============ */
.progress-container {
  margin-bottom: var(--space-lg);
}

.progress-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.375rem;
  font-size: var(--text-sm);
  color: var(--color-ink-2);
  font-weight: 500;
}

.progress-bar {
  height: 4px;
  background: var(--color-paper-3);
  border-radius: var(--radius-pill);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--color-accent);
  border-radius: var(--radius-pill);
  transition: width 400ms var(--ease-out);
}

/* ============ Button Group ============ */
.button-group {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
  margin-top: var(--space-lg);
  position: relative;
  z-index: 10;
}

.action-btn {
  padding: var(--space-md);
  border-radius: var(--radius-card);
  border: 1px solid var(--color-rule);
  background: var(--color-paper);
  color: var(--color-ink);
  cursor: pointer;
  transition: background var(--dur-short), box-shadow var(--dur-short);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
}

.action-btn:hover {
  background: var(--color-paper-2);
  box-shadow: var(--shadow-sm);
}

.action-btn-icon {
  font-size: 1.25rem;
}

.action-btn-label {
  font-weight: 600;
  font-size: var(--text-md);
}

.action-btn-sub {
  font-family: var(--font-label);
  font-size: var(--text-xs);
  color: var(--color-ink-2);
  letter-spacing: 0.02em;
}

/* Action button variants */
.action-btn.danger:hover {
  border-color: var(--color-accent);
}

.action-btn.warning:hover {
  border-color: var(--color-ink-2);
}

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

/* ============ Toast ============ */
.toast-container {
  position: fixed;
  top: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3000;
  max-width: 24rem;
  width: 90%;
}

.toast {
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-card);
  padding: var(--space-md);
  box-shadow: var(--shadow-lg);
  animation: fadeIn var(--dur-medium) var(--ease-out);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.toast-icon {
  font-size: 1rem;
  width: 1.75rem;
  height: 1.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.toast-content { flex: 1; }

.toast-title {
  font-weight: 600;
  margin-bottom: 0.125rem;
  font-size: var(--text-sm);
  color: var(--color-ink);
}

.toast-message {
  font-size: var(--text-sm);
  color: var(--color-ink-2);
  line-height: 1.5;
}

/* ============ Modal ============ */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: oklch(15% 0.006 60 / 0.5);
  backdrop-filter: blur(4px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-md);
}

.modal-content {
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-card);
  padding: var(--space-2xl);
  max-width: 26rem;
  width: 100%;
  position: relative;
  box-shadow: var(--shadow-lg);
}

.modal-close {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
  width: 2rem;
  height: 2rem;
  border-radius: var(--radius-input);
  background: transparent;
  border: 1px solid var(--color-rule);
  color: var(--color-ink-2);
  font-size: 1.25rem;
  cursor: pointer;
  transition: background var(--dur-short), color var(--dur-short);
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-close:hover {
  background: var(--color-paper-2);
  color: var(--color-ink);
}

/* ============ Input ============ */
.input-group {
  margin-bottom: var(--space-md);
}

.input-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  margin-bottom: 0.375rem;
  color: var(--color-ink);
}

.input-field {
  width: 100%;
  padding: 0.625rem 0.875rem;
  border-radius: var(--radius-input);
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-md);
  transition: border-color var(--dur-short), box-shadow var(--dur-short);
  outline: none;
}

.input-field:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px oklch(65% 0.18 30 / 0.1);
}

.input-field::placeholder {
  color: var(--color-ink-2);
  opacity: 0.5;
}

/* ============ Agreement Check ============ */
.agreement-check {
  margin-bottom: var(--space-sm);
}

.checkbox-label {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-size: var(--text-sm);
  color: var(--color-ink-2);
  cursor: pointer;
  line-height: 1.5;
}

.checkbox-label input[type="checkbox"] {
  width: 1rem;
  height: 1rem;
  margin: 0.125rem 0 0;
  accent-color: var(--color-accent);
  cursor: pointer;
  flex-shrink: 0;
}

.checkbox-label span {
  flex: 1;
}

.checkbox-label a {
  color: var(--color-accent);
  text-decoration: underline;
  transition: color var(--dur-short);
}

.checkbox-label a:hover {
  color: var(--color-accent-2);
}

/* ============ Footer (Ft2 - Inline Single Line) ============ */
.site-footer {
  background: var(--color-paper);
  border-top: 1px solid var(--color-rule);
  padding: var(--space-xl) var(--page-gutter);
  margin-top: var(--space-3xl);
  text-align: center;
}

.footer-content {
  max-width: var(--page-max);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

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

.footer-brand-text {
  font-family: var(--font-display);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-ink);
  letter-spacing: -0.01em;
}

.footer-tagline {
  font-size: var(--text-sm);
  color: var(--color-ink-2);
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  margin-bottom: var(--space-sm);
}

.footer-links a {
  color: var(--color-ink-2);
  text-decoration: none;
  font-size: var(--text-sm);
  transition: color var(--dur-short);
}

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

.footer-divider {
  color: var(--color-rule);
  user-select: none;
}

.footer-copyright {
  font-size: var(--text-sm);
  color: var(--color-ink-2);
}

/* ============ Utility Classes ============ */
.mb-8 { margin-bottom: var(--space-lg); }
.text-center { text-align: center; }
.flex { display: flex; }
.gap-4 { gap: var(--space-sm); }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.flex-wrap { flex-wrap: wrap; }
.inline-flex { display: inline-flex; }
.w-full { width: 100%; }

/* ============ Responsive ============ */
@media (max-width: 768px) {
  :root {
    --section-gap: 3rem;
    --page-gutter: 1rem;
  }

  .nav-pill { display: none; }

  .hero-section {
    max-width: 100%;
  }

  .hero-title {
    font-size: clamp(1.75rem, 6vw, 2.5rem);
  }

  .hero-buttons {
    flex-direction: column;
  }

  .word-card {
    height: 15rem;
  }

  .word-text {
    font-size: var(--text-2xl);
  }

  .button-group {
    grid-template-columns: 1fr;
  }

  .stats-grid {
    grid-template-columns: 1fr 1fr;
  }

  .wordbank-grid {
    grid-template-columns: 1fr;
  }

  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .footer-links {
    justify-content: center;
  }
}

@media (max-width: 414px) {
  :root {
    --section-gap: 2.5rem;
    --page-gutter: 0.875rem;
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 375px) {
  :root {
    --page-gutter: 0.75rem;
  }
}

@media (max-width: 320px) {
  :root {
    --page-gutter: 0.625rem;
  }
}

/* ============ Audio Button Animation ============ */
.audio-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  border-radius: 50%;
  color: var(--color-ink);
  cursor: pointer;
  transition: all 150ms;
  position: relative;
}

.audio-btn:hover {
  background: var(--color-paper-3);
  border-color: var(--color-ink-2);
}

.audio-btn.playing {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: white;
}

.audio-btn.playing svg {
  animation: audioPulse 1.2s ease-in-out infinite;
}

@keyframes audioPulse {
  0%, 100% {
    transform: scale(1);
    opacity: 1;
  }
  50% {
    transform: scale(1.15);
    opacity: 0.8;
  }
}

/* Sound wave bars animation */
.audio-waves {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  height: 16px;
}

.audio-wave {
  width: 2px;
  height: 100%;
  background: currentColor;
  border-radius: 1px;
  animation: wave 1.2s ease-in-out infinite;
}

.audio-wave:nth-child(1) { animation-delay: 0s; }
.audio-wave:nth-child(2) { animation-delay: 0.15s; }
.audio-wave:nth-child(3) { animation-delay: 0.3s; }
.audio-wave:nth-child(4) { animation-delay: 0.45s; }

@keyframes wave {
  0%, 100% {
    transform: scaleY(0.3);
  }
  50% {
    transform: scaleY(1);
  }
}