:root {
  --color-bg: #0a0f1a;
  --color-surface: rgba(15, 23, 42, 0.82);
  --color-card: rgba(30, 41, 59, 0.6);
  --color-accent: #7dd3fc;
  --color-highlight: #facc15;
  --color-success: #4ade80;
  --color-text: #f1f5f9;
  --color-muted: #94a3b8;
  --color-border: rgba(148, 163, 184, 0.12);
  --color-danger: rgba(239, 68, 68, 0.95);
  --shadow-elevated: 0 8px 32px rgba(0, 0, 0, 0.3);
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --transition-fast: 0.18s ease;
  font-family: -apple-system, 'Inter', 'Segoe UI', system-ui, sans-serif;
  -webkit-tap-highlight-color: transparent;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  min-height: 100%;
}

body {
  min-height: 100vh;
  min-height: 100dvh;
  background: var(--color-bg);
  color: var(--color-text);
  -webkit-text-size-adjust: 100%;
}

button, input, select {
  font: inherit;
  -webkit-appearance: none;
}

#app {
  min-height: 100vh;
  min-height: 100dvh;
}

/* ── Shell ── */

.shell {
  max-width: 1280px;
  margin: 0 auto;
  padding: 12px 12px 32px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.shell--loading {
  display: grid;
  place-items: center;
  min-height: 100vh;
  min-height: 100dvh;
  padding: 24px;
}

/* ── Panels ── */

.panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(16px);
}

/* ── Header ── */

.app-header {
  display: flex;
  flex-direction: column;
  gap: 0;
  padding: 14px 16px;
}

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

.app-header__title {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.app-header__logo {
  font-size: 1.3rem;
  flex-shrink: 0;
}

.app-header h1 {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.app-header__date {
  color: var(--color-muted);
  font-size: 0.78rem;
  display: block;
  margin-top: 1px;
}

.app-header__user-bar {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  padding-top: 10px;
  margin-top: 10px;
  border-top: 1px solid var(--color-border);
}


/* ── Navigation ── */

.app-nav {
  display: flex;
  gap: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.app-nav__tab {
  flex: 1;
  padding: 10px 16px;
  border: none;
  background: transparent;
  color: var(--color-muted);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.app-nav__tab.is-active {
  background: rgba(125, 211, 252, 0.1);
  color: var(--color-accent);
}

.app-nav__badge {
  font-size: 0.72rem;
  color: var(--color-muted);
  background: rgba(148, 163, 184, 0.12);
  padding: 1px 7px;
  border-radius: 999px;
  min-width: 20px;
  text-align: center;
}

.app-nav__tab.is-active .app-nav__badge {
  background: rgba(125, 211, 252, 0.15);
  color: var(--color-accent);
}

/* ── Known Words Page ── */

.panel--known-page {
  padding: 14px;
}

.panel--known-page .known-bar__tags {
  margin-top: 12px;
}

/* ── Toolbar ── */

.toolbar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  padding: 10px 14px;
}

.toolbar__group {
  display: flex;
  align-items: center;
  gap: 6px;
}

.toolbar__label {
  color: var(--color-muted);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.toolbar__spacer {
  flex: 1;
  min-width: 8px;
}

.source-switch {
  display: flex;
  gap: 2px;
  padding: 3px;
  background: rgba(30, 41, 59, 0.6);
  border-radius: 999px;
}

.source-switch__button {
  padding: 6px 12px;
  border-radius: 999px;
  background: transparent;
  color: var(--color-muted);
  font-size: 0.85rem;
  border: none;
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast);
}

.source-switch__button.is-active {
  background: var(--color-accent);
  color: #0c1929;
  font-weight: 600;
}

.source-switch__button:active:not(.is-active) {
  background: rgba(125, 211, 252, 0.12);
}

select {
  background: rgba(15, 23, 42, 0.8);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  font-size: 0.85rem;
}

.toggle-switch {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  white-space: nowrap;
}

.toggle-switch__track {
  position: relative;
  width: 36px;
  height: 20px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.25);
  transition: background var(--transition-fast);
  flex-shrink: 0;
}

.toggle-switch__thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-muted);
  transition: transform var(--transition-fast), background var(--transition-fast);
}

.toggle-switch__track.is-active {
  background: rgba(125, 211, 252, 0.3);
}

.toggle-switch__track.is-active .toggle-switch__thumb {
  transform: translateX(16px);
  background: var(--color-accent);
}

.toggle-switch__label {
  font-size: 0.8rem;
  color: var(--color-muted);
}

/* ── Summary Bar ── */

.summary-bar {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 4px 0 8px;
  font-size: 0.8rem;
  background: none;
  border: none;
  border-radius: 0;
  backdrop-filter: none;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 4px;
}

.summary-bar__row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.summary-bar__item {
  display: flex;
  align-items: center;
  gap: 4px;
  color: var(--color-muted);
}

.summary-bar__value {
  color: var(--color-text);
  font-weight: 600;
}

/* ── Trend List ── */

.panel--trends {
  padding: 14px;
}

.panel--trends .panel__header {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 10px;
  padding: 0 2px;
}

.panel--trends .panel__header h2 {
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
}

.panel--trends .panel__header p {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.78rem;
}

.trend-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
  padding: 8px 10px;
  margin-bottom: 6px;
  font-size: 0.72rem;
  color: var(--color-muted);
  border-radius: var(--radius-sm);
  background: rgba(30, 41, 59, 0.4);
  line-height: 1.5;
}

.trend-legend strong {
  color: var(--color-text);
}

.trend-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

/* ── Trend Card ── */

.trend-card {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 10px;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
  min-height: 44px;
}

.trend-card:active {
  background: rgba(125, 211, 252, 0.06);
}

.trend-card.is-known {
  opacity: 0.45;
}

.trend-card__rank {
  width: 24px;
  text-align: center;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-muted);
  flex-shrink: 0;
}

.trend-card__word {
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.trend-card__pos {
  flex-shrink: 0;
  padding: 2px 6px;
  border-radius: 5px;
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.trend-card__pos--noun {
  background: rgba(96, 165, 250, 0.15);
  color: #93bbfd;
}

.trend-card__pos--propn {
  background: rgba(192, 132, 252, 0.15);
  color: #c4b5fd;
}

.trend-card__pos--verb {
  background: rgba(52, 211, 153, 0.15);
  color: #6ee7b7;
}

.trend-card__pos--adj {
  background: rgba(251, 191, 36, 0.15);
  color: #fcd34d;
}

.trend-card__freq {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 5px;
  margin-left: auto;
  font-size: 0.72rem;
  color: var(--color-muted);
  white-space: nowrap;
}

.trend-card__bar {
  width: 36px;
  height: 3px;
  border-radius: 2px;
  background: rgba(148, 163, 184, 0.15);
  overflow: hidden;
}

.trend-card__bar-fill {
  height: 100%;
  border-radius: 2px;
  background: var(--color-accent);
  transition: width 0.3s ease;
}

.trend-card__ratio {
  width: 28px;
  text-align: right;
}

.trend-card__known-btn {
  flex-shrink: 0;
  width: 38px;
  height: 38px;
  border-radius: 8px;
  border: 2px solid rgba(241, 245, 249, 0.45);
  background: transparent;
  color: var(--color-muted);
  cursor: pointer;
  display: grid;
  place-items: center;
  font-size: 1.05rem;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.trend-card__known-btn:active {
  background: rgba(125, 211, 252, 0.12);
}

.trend-card__known-btn.is-known {
  background: rgba(74, 222, 128, 0.12);
  border-color: rgba(74, 222, 128, 0.3);
  color: var(--color-success);
}

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

/* ── Sidebar: Auth ── */

.auth-card {
  padding: 20px 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.auth-card h2 {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
}

.auth-card__copy {
  color: var(--color-muted);
  font-size: 0.82rem;
  line-height: 1.5;
  margin: 0;
}

.auth-card--collapsed {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
}

.auth-card--collapsed .auth-card__copy {
  flex: 1;
  margin: 0;
}

.auth-card--collapsed .button {
  flex-shrink: 0;
  width: auto;
}

.auth-card__features {
  margin: 0;
  padding: 0 0 0 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.82rem;
  line-height: 1.45;
  color: var(--color-muted);
}

.auth-card__features li::marker {
  color: var(--color-accent);
}

.auth-card__tabs {
  display: flex;
  gap: 2px;
  padding: 3px;
  background: rgba(30, 41, 59, 0.6);
  border-radius: 999px;
  align-self: flex-start;
}

.tab-button {
  padding: 7px 14px;
  border-radius: 999px;
  background: transparent;
  color: var(--color-muted);
  font-size: 0.82rem;
  border: none;
  cursor: pointer;
  transition: background var(--transition-fast), color var(--transition-fast);
}

.tab-button.is-active {
  background: var(--color-accent);
  color: #0c1929;
  font-weight: 600;
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.auth-form label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 0.82rem;
  color: var(--color-muted);
}

.auth-form input {
  background: rgba(8, 15, 26, 0.7);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px;
  font-size: 16px;
}

.auth-form input:focus {
  outline: none;
  border-color: var(--color-accent);
}

/* ── Buttons ── */

.button {
  border: none;
  cursor: pointer;
  border-radius: 999px;
  padding: 12px 18px;
  font-weight: 600;
  font-size: 0.88rem;
  transition: background var(--transition-fast);
}

.button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.button--primary {
  background: var(--color-accent);
  color: #0c1929;
  width: 100%;
}

.button--primary:active:not(:disabled) {
  background: #60c5f5;
}

.button--ghost {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
  padding: 8px 14px;
}

.button--small {
  padding: 6px 10px;
  font-size: 0.8rem;
}

.button--danger {
  background: var(--color-danger);
  color: #fff;
  border: none;
}

/* ── Auth Form Newsletter ── */

.auth-form__newsletter {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  background: rgba(125, 211, 252, 0.04);
  border: 1px solid var(--color-border);
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
}

/* ── Profile Page ── */

.profile-page {
  padding: 14px;
}

.profile-section {
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.profile-section:last-child {
  border-bottom: none;
}

.profile-section h3 {
  margin: 0 0 10px;
  font-size: 0.9rem;
  font-weight: 600;
}

.profile-section p {
  margin: 0 0 10px;
  font-size: 0.82rem;
  color: var(--color-muted);
}

.profile-form {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-width: 360px;
}

.profile-form label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 0.82rem;
  color: var(--color-muted);
}

.profile-form input {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: rgba(15, 23, 42, 0.5);
  color: var(--color-text);
}

.profile-section--danger {
  padding-top: 20px;
}

/* ── Known Words Tags ── */

.known-bar__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}

.known-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 8px;
  border-radius: 999px;
  font-size: 0.78rem;
  background: rgba(74, 222, 128, 0.08);
  border: 1px solid rgba(74, 222, 128, 0.18);
  color: var(--color-text);
}

.known-tag button {
  padding: 0;
  width: 16px;
  height: 16px;
  font-size: 0.7rem;
  border: none;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: transparent;
  color: var(--color-muted);
  cursor: pointer;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.known-tag button:active {
  background: rgba(239, 68, 68, 0.3);
  color: var(--color-text);
}

/* ── Empty / Loading States ── */

.empty-state {
  padding: 32px 12px;
  text-align: center;
}

.empty-state h3 {
  margin: 0 0 4px;
  font-size: 0.95rem;
}

.empty-state p {
  color: var(--color-muted);
  font-size: 0.82rem;
  line-height: 1.5;
}

.loading-card {
  padding: 32px 24px;
  text-align: center;
}

.loading-card h1 {
  margin: 0 0 6px;
  font-size: 1.3rem;
}

.loading-card p {
  color: var(--color-muted);
  font-size: 0.88rem;
}

.eyebrow {
  margin: 0 0 6px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-accent);
  font-size: 0.7rem;
}

/* ── Footer ── */

.app-footer {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 24px 0 8px;
  font-size: 0.78rem;
  color: var(--color-muted);
}

.app-footer a {
  color: var(--color-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.app-footer a:hover,
.app-footer a:active {
  color: var(--color-accent);
}

.app-footer__icon {
  width: 14px;
  height: 14px;
}

/* ── Toast ── */

.toast {
  position: fixed;
  left: 12px;
  right: 12px;
  bottom: 12px;
  background: var(--color-danger);
  color: #fff;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity var(--transition-fast), transform var(--transition-fast);
  box-shadow: var(--shadow-elevated);
  text-align: center;
}

.toast.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.toast--success {
  background: rgba(22, 163, 74, 0.95);
}

/* ── Desktop ── */

@media (min-width: 768px) {
  .shell {
    padding: 24px clamp(20px, 4vw, 40px) 48px;
    gap: 14px;
  }

  .app-header {
    padding: 18px 24px;
  }

  .app-header h1 {
    font-size: 1.25rem;
  }

  .toolbar {
    padding: 12px 20px;
    gap: 14px;
  }

  .summary-bar {
    padding: 14px 20px;
  }

  .panel--trends {
    padding: 20px;
  }

  .trend-card {
    gap: 12px;
    padding: 12px 14px;
  }

  .trend-card__rank {
    width: 28px;
    font-size: 0.8rem;
  }

  .trend-card__word {
    font-size: 1.15rem;
  }

  .trend-card__bar {
    width: 48px;
  }

  .auth-card {
    padding: 24px;
  }

  .toast {
    left: auto;
    right: 20px;
    bottom: 20px;
    max-width: 360px;
    text-align: left;
  }
}

@media (min-width: 1024px) {
  .trend-card:hover {
    background: rgba(125, 211, 252, 0.04);
  }

  .trend-card__known-btn:hover:not(.is-known) {
    border-color: var(--color-accent);
    color: var(--color-accent);
    background: rgba(125, 211, 252, 0.08);
  }
}