/* ==========================================================================
   Relay — Design Tokens
   ========================================================================== */
:root {
  /* Color */
  --bg-canvas: #0D0B14;
  --bg-surface: #161224;
  --bg-surface-raised: #1E1836;
  --bubble-in: #221C35;
  --bubble-out: #3B2E58;
  --text-primary: #F1EEF9;
  --text-muted: #9A93B0;
  --accent: #6E56CF;
  --accent-hover: #7F68DC;
  --accent-active: #5E48B8;
  --highlight: #9C81F5;
  --border-hairline: rgba(241, 238, 249, 0.07);
  --online: #4ADE80;
  --danger: #E5606B;

  /* Type */
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --fs-xs: 0.75rem;
  --fs-sm: 0.8125rem;
  --fs-base: 0.9375rem;
  --fs-md: 1rem;
  --fs-lg: 1.25rem;
  --fs-xl: 1.5rem;

  /* Spacing scale */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 20px;
  --sp-6: 24px;

  /* Radius */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 999px;

  /* Motion */
  --ease-standard: cubic-bezier(0.4, 0, 0.2, 1);
  --duration-fast: 120ms;
  --duration-med: 220ms;

  /* Layout */
  --sidebar-w: 360px;
  --header-h: 68px;
}

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

[hidden] { display: none !important; }

html, body {
  height: 100%;
  width: 100%;
  margin: 0;
  padding: 0;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  overflow: hidden;
  overscroll-behavior: none;
}

body {
  background: var(--bg-canvas);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
}

button {
  font-family: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

input {
  font-family: inherit;
  color: inherit;
}

img, svg { display: block; }

a { color: inherit; }

/* ==========================================================================
   Scrollbars — themed to match the app palette instead of the OS default
   ========================================================================== */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--bg-surface-raised) var(--bg-canvas);
}

*::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
*::-webkit-scrollbar-track {
  background: var(--bg-canvas);
}
*::-webkit-scrollbar-thumb {
  background-color: var(--bg-surface-raised);
  border-radius: var(--radius-full);
  border: 2px solid var(--bg-canvas);
}
*::-webkit-scrollbar-thumb:hover {
  background-color: var(--accent);
}
*::-webkit-scrollbar-corner {
  background: var(--bg-canvas);
}

.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;
}

/* Visible keyboard focus everywhere */
button:focus-visible,
input:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--highlight);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

/* Reusable min touch target */
.icon-btn {
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  color: var(--text-muted);
  transition: background var(--duration-fast) var(--ease-standard),
              color var(--duration-fast) var(--ease-standard);
}
.icon-btn:hover { background: var(--bg-surface-raised); color: var(--text-primary); }
.icon-btn:active { transform: scale(0.94); }

/* ==========================================================================
   App Shell
   ========================================================================== */
.app {
  height: 100%;
  height: 100dvh;
  width: 100%;
  max-height: 100%;
  overflow: hidden;
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  background: var(--bg-canvas);
}

/* ==========================================================================
   Sidebar
   ========================================================================== */
.sidebar {
  background: var(--bg-surface);
  border-right: 1px solid var(--border-hairline);
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  position: relative;
}

.sidebar__header {
  height: var(--header-h);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--sp-5);
  background: var(--bg-surface-raised);
  border-bottom: 1px solid rgba(110, 86, 207, 0.25);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.35);
  position: relative;
  z-index: 10;
}

.logo {
  font-size: var(--fs-xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0;
}
.logo__dot { color: var(--accent); }

.logo__link {
  color: inherit;
  text-decoration: none;
}
.logo__link:hover { color: inherit; }

.sidebar__actions {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}

.avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--text-primary);
  background-color: var(--accent);
  background-size: cover;
  background-position: center;
  flex-shrink: 0;
}
.avatar--sm { width: 40px; height: 40px; font-size: var(--fs-xs); }
.avatar--md { width: 44px; height: 44px; font-size: var(--fs-sm); }
.avatar--xl { width: 72px; height: 72px; font-size: var(--fs-lg); }

.avatar-badge {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-full);
  padding: 2px;
  box-shadow: 0 0 0 2px var(--accent);
  display: inline-flex;
  text-decoration: none;
  cursor: pointer;
  transition: box-shadow var(--duration-fast) var(--ease-standard);
}
.avatar-badge:hover { box-shadow: 0 0 0 2px var(--accent-hover); }
.avatar--me { width: 100%; height: 100%; font-size: var(--fs-xs); }

/* Search reveal */
.search-bar {
  padding: 0 var(--sp-5) var(--sp-3);
}
.search-bar input {
  width: 100%;
  height: 40px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-hairline);
  background: var(--bg-canvas);
  color: var(--text-primary);
  padding: 0 var(--sp-4);
  font-size: var(--fs-sm);
}
.search-bar input::placeholder { color: var(--text-muted); }

/* Conversation list */
.conv-list {
  flex: 1;
  overflow-y: auto;
  padding: var(--sp-2) var(--sp-3) var(--sp-6);
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.conv-item {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  width: 100%;
  padding: var(--sp-3) var(--sp-3);
  border-radius: var(--radius-md);
  border-left: 3px solid transparent;
  text-align: left;
  min-height: 44px;
  transition: background var(--duration-fast) var(--ease-standard);
}

.conv-item:hover { background: rgba(241, 238, 249, 0.03); }

.conv-item.is-active {
  background: var(--bg-surface-raised);
  border-left-color: var(--accent);
}

.conv-item__body {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.conv-item__top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--sp-2);
}

.conv-item__name {
  font-size: var(--fs-base);
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.conv-item__time {
  font-size: var(--fs-xs);
  color: var(--text-muted);
  flex-shrink: 0;
}
.conv-item.is-active .conv-item__time,
.conv-item.has-unread .conv-item__time { color: var(--highlight); }

.conv-item__preview-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-2);
}

.conv-item__preview {
  font-size: var(--fs-sm);
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.conv-item.has-unread .conv-item__preview { color: var(--text-primary); }

.unread-badge {
  flex-shrink: 0;
  min-width: 20px;
  height: 20px;
  padding: 0 6px;
  border-radius: var(--radius-full);
  background: var(--highlight);
  color: #1A0F33;
  font-size: 0.6875rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.avatar-wrap { position: relative; flex-shrink: 0; }
.presence-dot {
  position: absolute;
  bottom: -1px;
  right: -1px;
  width: 11px;
  height: 11px;
  border-radius: var(--radius-full);
  background: var(--online);
  border: 2px solid var(--bg-surface);
}

.fab {
  position: absolute;
  bottom: var(--sp-6);
  right: var(--sp-6);
  width: 52px;
  height: 52px;
  border-radius: var(--radius-full);
  background: var(--accent);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 24px rgba(110, 86, 207, 0.45);
  text-decoration: none;
  cursor: pointer;
  transition: background var(--duration-fast) var(--ease-standard), transform var(--duration-fast) var(--ease-standard);
}
.fab:hover { background: var(--accent-hover); }
.fab:active { transform: scale(0.94); }

/* ==========================================================================
   Chat Window
   ========================================================================== */
.chat {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  height: 100%;
  max-height: 100%;
  overflow: hidden;
  background:
    radial-gradient(ellipse 900px 500px at 85% -10%, rgba(110, 86, 207, 0.16), transparent 60%),
    var(--bg-canvas);
}

.chat__header {
  height: var(--header-h);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: 0 var(--sp-5);
  background: var(--bg-surface-raised);
  border-bottom: 1px solid rgba(110, 86, 207, 0.25);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.35);
  position: relative;
  z-index: 10;
  flex-shrink: 0;
}

.back-btn { display: none; }

.chat__identity {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  flex: 1;
  min-width: 0;
}

.chat__who {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.chat__name {
  font-size: var(--fs-base);
  font-weight: 700;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.chat__status {
  font-size: var(--fs-xs);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 5px;
}

.chat__handle { color: var(--text-muted); }
.chat__status.is-online { color: var(--online); font-weight: 500; }
.chat__status-sep { color: var(--border-hairline); }

.status-dot {
  width: 7px;
  height: 7px;
  border-radius: var(--radius-full);
  background: var(--online);
  flex-shrink: 0;
}

.chat__actions {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
}

/* Chat header dropdown menu */
.menu {
  position: relative;
}

.menu__dropdown {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  min-width: 180px;
  padding: var(--sp-2);
  background: var(--bg-surface-raised);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.4);
  z-index: 10;
}

.menu__item {
  width: 100%;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--text-primary);
  text-align: left;
  min-height: 40px;
  transition: background var(--duration-fast) var(--ease-standard);
}
.menu__item:hover { background: var(--bg-surface); }
.menu__item svg { flex-shrink: 0; }

.menu__item--danger { color: var(--danger); }

/* Empty chat pane, shown once every conversation has been deleted */
.chat__empty {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--sp-6);
  gap: var(--sp-2);
}

.chat__empty-title {
  font-size: var(--fs-md);
  font-weight: 700;
  margin: 0;
}

.chat__empty-body {
  font-size: var(--fs-sm);
  color: var(--text-muted);
  margin: 0;
  max-width: 32ch;
}

/* Message thread */
.thread {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: var(--sp-6) var(--sp-6) var(--sp-3);
  display: flex;
  flex-direction: column;
  gap: 2px;
}

/* Themed scrollbars — matches the app's violet/purple palette instead
   of the OS default. Applied to any scrollable pane (thread, conv list). */
.thread,
.conv-list {
  scrollbar-width: thin; /* Firefox */
  scrollbar-color: var(--bg-surface-raised) transparent; /* Firefox */
}

.thread::-webkit-scrollbar,
.conv-list::-webkit-scrollbar {
  width: 8px;
}

.thread::-webkit-scrollbar-track,
.conv-list::-webkit-scrollbar-track {
  background: transparent;
}

.thread::-webkit-scrollbar-thumb,
.conv-list::-webkit-scrollbar-thumb {
  background-color: var(--bg-surface-raised);
  border-radius: var(--radius-full);
  border: 2px solid transparent;
  background-clip: padding-box;
}

.thread::-webkit-scrollbar-thumb:hover,
.conv-list::-webkit-scrollbar-thumb:hover {
  background-color: var(--accent);
}

.day-divider {
  text-align: center;
  color: var(--text-muted);
  font-size: var(--fs-xs);
  margin: var(--sp-4) 0;
}

.msg-row {
  display: flex;
  margin-bottom: 2px;
  max-width: 100%;
}
.msg-row.is-out { justify-content: flex-end; }
.msg-row.is-in { justify-content: flex-start; }

/* Grouping spacing: extra gap before a new sender block */
.msg-row.group-start { margin-top: var(--sp-4); }

.bubble {
  max-width: min(480px, 68%);
  padding: 10px var(--sp-4);
  border-radius: var(--radius-lg);
  font-size: var(--fs-base);
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.bubble__text { white-space: pre-wrap; word-break: break-word; }

.bubble__meta {
  align-self: flex-end;
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 0.6875rem;
  opacity: 0.7;
}

.is-in .bubble {
  background: var(--bubble-in);
  color: var(--text-primary);
  border-bottom-left-radius: var(--radius-sm);
}
.is-out .bubble {
  background: var(--bubble-out);
  color: var(--text-primary);
  border-bottom-right-radius: var(--radius-sm);
}

/* Consecutive message grouping — flatten shared edge */
.msg-row.is-in.group-mid .bubble,
.msg-row.is-in.group-end .bubble { border-top-left-radius: var(--radius-sm); }
.msg-row.is-in.group-start .bubble,
.msg-row.is-in.group-mid .bubble { border-bottom-left-radius: var(--radius-sm); }

.msg-row.is-out.group-mid .bubble,
.msg-row.is-out.group-end .bubble { border-top-right-radius: var(--radius-sm); }
.msg-row.is-out.group-start .bubble,
.msg-row.is-out.group-mid .bubble { border-bottom-right-radius: var(--radius-sm); }

.checkmarks { display: inline-flex; }
.checkmarks.is-read { color: var(--highlight); opacity: 1; }

/* Composer */
.composer {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-5);
  padding-bottom: calc(var(--sp-3) + env(safe-area-inset-bottom));
  border-top: 1px solid var(--border-hairline);
  background: var(--bg-canvas);
}

.composer__input {
  flex: 1;
  height: 44px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-hairline);
  background: var(--bg-surface);
  padding: 0 var(--sp-5);
  font-size: var(--fs-base);
}
.composer__input::placeholder { color: var(--text-muted); }

.send-btn {
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  border-radius: var(--radius-full);
  background: var(--bg-surface-raised);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--duration-fast) var(--ease-standard),
              color var(--duration-fast) var(--ease-standard),
              transform var(--duration-fast) var(--ease-standard);
}
.send-btn.is-active {
  background: var(--accent);
  color: var(--text-primary);
}
.send-btn.is-active:hover { background: var(--accent-hover); }
.send-btn:active { transform: scale(0.92); }
.send-btn:disabled { cursor: default; }

/* ==========================================================================
   Responsive: Mobile (< 768px)
   ========================================================================== */
@media (max-width: 767px) {
  .sidebar__header,
  .chat__header,
  .adduser-topbar,
  .auth-topbar {
    background: #181328;
    border-bottom: 1px solid rgba(156, 129, 245, 0.25);
    box-shadow: 0 4px 18px rgba(0, 0, 0, 0.45);
    position: relative;
    z-index: 10;
  }

  .app {
    grid-template-columns: 1fr;
    height: 100%;
    height: 100dvh;
    max-height: 100%;
    overflow: hidden;
  }

  .sidebar,
  .chat {
    grid-column: 1 / -1;
    grid-row: 1 / -1;
    height: 100%;
    max-height: 100%;
    overflow: hidden;
  }

  /* Sidebar and chat occupy the same slot; visibility is toggled */
  .app:not(.is-chat-open) .chat { display: none; }
  .app.is-chat-open .sidebar { display: none; }

  .back-btn { display: inline-flex; }

  .thread { padding: var(--sp-4) var(--sp-4) var(--sp-2); }
  .bubble { max-width: 82%; }

  .fab { bottom: calc(var(--sp-5) + env(safe-area-inset-bottom)); right: var(--sp-5); }
}

@media (min-width: 768px) {
  .sidebar { display: flex; }
  .chat { display: flex; }
}
/* ==========================================================================
   Relay — Login Page
   Extends styles.css tokens. Loaded after styles.css.
   ========================================================================== */

.auth-body {
  overflow-y: auto;
  height: auto;
  min-height: 100%;
}

/* Top bar — same logo treatment as the app shell, no actions since
   there's no session yet. */
.auth-topbar {
  height: var(--header-h);
  display: flex;
  align-items: center;
  padding: 0 var(--sp-6);
  border-bottom: 1px solid var(--border-hairline);
}

.auth-main {
  min-height: calc(100vh - var(--header-h));
  min-height: calc(100dvh - var(--header-h));
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--sp-6);
  background:
    radial-gradient(ellipse 700px 460px at 18% 0%, rgba(110, 86, 207, 0.14), transparent 60%),
    radial-gradient(ellipse 600px 420px at 100% 100%, rgba(156, 129, 245, 0.08), transparent 55%),
    var(--bg-canvas);
}

.auth-card {
  width: 100%;
  max-width: 400px;
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

/* A quiet callback to the 3px accent line used on active conversations —
   the one place this page spends its "boldness". */
.auth-card__accent {
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
}

.auth-card__content {
  padding: var(--sp-6) var(--sp-6) var(--sp-6);
}

.auth-title {
  font-size: var(--fs-xl);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 var(--sp-1);
}

.auth-subtitle {
  font-size: var(--fs-sm);
  color: var(--text-muted);
  margin: 0 0 var(--sp-6);
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
}

.field {
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
}

.field__label-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
}

.field__label {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--text-primary);
}

.field__link {
  font-size: var(--fs-xs);
  color: var(--highlight);
  text-decoration: none;
}
.field__link:hover { text-decoration: underline; }

.field__input {
  height: 46px;
  width: 100%;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-hairline);
  background: var(--bg-canvas);
  padding: 0 var(--sp-4);
  font-size: var(--fs-base);
  transition: border-color var(--duration-fast) var(--ease-standard);
}
.field__input::placeholder { color: var(--text-muted); }
.field__input:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(110, 86, 207, 0.25);
}

.field.has-error .field__input {
  border-color: var(--danger);
}
.field.has-error .field__input:focus-visible {
  box-shadow: 0 0 0 3px rgba(229, 96, 107, 0.2);
}

.field__error {
  font-size: var(--fs-xs);
  color: var(--danger);
  margin: 0;
}

.field__hint {
  font-size: var(--fs-xs);
  color: var(--text-muted);
  margin: 0;
}

/* Password strength meter */
.strength-meter {
  display: flex;
  gap: 5px;
}
.strength-meter__bar {
  flex: 1;
  height: 3px;
  border-radius: var(--radius-full);
  background: var(--border-hairline);
  transition: background var(--duration-med) var(--ease-standard);
}
.strength-meter.is-weak [data-bar]:nth-child(1) { background: var(--danger); }
.strength-meter.is-fair [data-bar]:nth-child(-n+2) { background: var(--highlight); }
.strength-meter.is-strong [data-bar] { background: var(--online); }

/* Username field */
.username-wrap { position: relative; }

.username-prefix {
  position: absolute;
  left: var(--sp-4);
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: var(--fs-base);
  pointer-events: none;
}

.field__input.has-prefix {
  padding-left: 26px;
  padding-right: 40px;
}

.username-status {
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.username-status .spinner {
  width: 14px;
  height: 14px;
  border-width: 2px;
}

.username-status svg { display: block; }
.username-status .icon-available { color: var(--online); }
.username-status .icon-taken { color: var(--danger); }

.field__hint.is-checking { color: var(--text-muted); }
.field__hint.is-available { color: var(--online); }
.field__hint.is-taken,
.field__hint.is-invalid { color: var(--danger); }

.field__input-wrap { position: relative; }
.field__input-wrap .field__input { padding-right: 46px; }

.field__reveal {
  position: absolute;
  right: 2px;
  top: 50%;
  transform: translateY(-50%);
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  color: var(--text-muted);
  transition: color var(--duration-fast) var(--ease-standard);
}
.field__reveal:hover { color: var(--text-primary); }

/* Checkbox */
.field--row { flex-direction: row; }

.checkbox {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  cursor: pointer;
  min-height: 44px;
}

.checkbox input {
  position: absolute;
  opacity: 0;
  width: 20px;
  height: 20px;
  margin: 0;
  cursor: pointer;
}

.checkbox__box {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  border-radius: 5px;
  border: 1px solid var(--border-hairline);
  background: var(--bg-canvas);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background var(--duration-fast) var(--ease-standard),
              border-color var(--duration-fast) var(--ease-standard);
}

.checkbox input:checked + .checkbox__box {
  background: var(--accent);
  border-color: var(--accent);
}
.checkbox input:checked + .checkbox__box::after {
  content: "";
  width: 10px;
  height: 6px;
  border-left: 2px solid var(--text-primary);
  border-bottom: 2px solid var(--text-primary);
  transform: rotate(-45deg) translateY(-1px);
}
.checkbox input:focus-visible + .checkbox__box {
  outline: 2px solid var(--highlight);
  outline-offset: 2px;
}

.checkbox__label {
  font-size: var(--fs-sm);
  color: var(--text-muted);
}

/* Form-level error banner */
.form-error {
  font-size: var(--fs-sm);
  color: var(--danger);
  background: rgba(229, 96, 107, 0.1);
  border: 1px solid rgba(229, 96, 107, 0.3);
  border-radius: var(--radius-sm);
  padding: var(--sp-3);
  margin: 0;
}

/* Submit button */
.auth-submit {
  height: 46px;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: var(--text-primary);
  font-size: var(--fs-base);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  transition: background var(--duration-fast) var(--ease-standard),
              transform var(--duration-fast) var(--ease-standard),
              opacity var(--duration-fast) var(--ease-standard);
}
.auth-submit:hover { background: var(--accent-hover); }
.auth-submit:active { transform: scale(0.98); }
.auth-submit:disabled { opacity: 0.6; cursor: default; }

.auth-submit.is-loading .auth-submit__label { opacity: 0.85; }

.spinner {
  width: 16px;
  height: 16px;
  border-radius: var(--radius-full);
  border: 2px solid rgba(241, 238, 249, 0.35);
  border-top-color: var(--text-primary);
  animation: spin 0.7s linear infinite;
  flex-shrink: 0;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Divider */
.auth-divider {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  margin: var(--sp-6) 0 var(--sp-4);
  color: var(--text-muted);
  font-size: var(--fs-xs);
}
.auth-divider::before,
.auth-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border-hairline);
}

.auth-switch {
  text-align: center;
  font-size: var(--fs-sm);
  color: var(--text-muted);
  margin: 0;
}
.auth-switch a {
  color: var(--highlight);
  text-decoration: none;
  font-weight: 600;
}
.auth-switch a:hover { text-decoration: underline; }

/* Social sign-in (Google) */
.auth-social {
  height: 46px;
  width: 100%;
  border-radius: var(--radius-sm);
  background: var(--bg-surface-raised);
  border: 1px solid var(--border-hairline);
  color: var(--text-primary);
  font-size: var(--fs-base);
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-3);
  margin-bottom: var(--sp-5);
  transition: background var(--duration-fast) var(--ease-standard),
              transform var(--duration-fast) var(--ease-standard),
              opacity var(--duration-fast) var(--ease-standard);
}
.auth-social:hover { background: var(--bg-surface); border-color: var(--text-muted); }
.auth-social:active { transform: scale(0.98); }
.auth-social:disabled { opacity: 0.6; cursor: default; }
.auth-social__icon { flex-shrink: 0; }
.auth-social.is-loading .auth-social__label { opacity: 0.85; }


@media (prefers-reduced-motion: reduce) {
  .spinner { animation: none; }
}

/* ==========================================================================
   Relay — New Message / Add User
   Extends styles.css tokens. Loaded after styles.css.
   ========================================================================== */

.adduser-body {
  overflow-y: auto;
  height: auto;
  min-height: 100%;
}

.adduser-page {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.adduser-topbar {
  height: var(--header-h);
  min-height: var(--header-h);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--sp-6);
  background: var(--bg-canvas);
  box-shadow: 0 1px 0 var(--border-hairline);
  position: relative;
  z-index: 1;
}

.adduser-main {
  flex: 1;
  display: flex;
  justify-content: center;
  padding: 12vh var(--sp-6) var(--sp-6);
  background:
    radial-gradient(ellipse 900px 650px at 25% 0%, rgba(110, 86, 207, 0.30), transparent 60%),
    radial-gradient(ellipse 700px 550px at 90% 25%, rgba(156, 129, 245, 0.14), transparent 55%),
    var(--bg-surface);
}

.adduser-block {
  width: 100%;
  max-width: 760px;
}

.adduser-heading {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 var(--sp-3);
}

.adduser-searchbar {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  height: 64px;
  padding: 0 var(--sp-5);
  border-radius: var(--radius-full);
  border: 1px solid rgba(110, 86, 207, 0.45);
  background: rgba(22, 18, 36, 0.65);
  transition: border-color var(--duration-fast) var(--ease-standard),
              box-shadow var(--duration-fast) var(--ease-standard);
}

.adduser-searchbar:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(110, 86, 207, 0.22);
}

.adduser-searchbar svg { color: var(--highlight); flex-shrink: 0; }

.adduser-searchbar input {
  flex: 1;
  height: 100%;
  min-width: 0;
  background: none;
  border: none;
  font-size: var(--fs-md);
  color: var(--text-primary);
}
.adduser-searchbar input::placeholder { color: var(--text-muted); }
.adduser-searchbar input:focus-visible { outline: none; }

.adduser__results {
  margin-top: var(--sp-5);
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.adduser__empty {
  padding: var(--sp-5) var(--sp-2);
  font-size: var(--fs-sm);
  color: var(--text-muted);
  margin: 0;
}

@media (max-width: 600px) {
  .adduser-main { padding-top: 8vh; }
  .adduser-searchbar { height: 56px; }
}

/* ==========================================================================
   Relay — Settings
   Extends styles.css tokens. Loaded after styles.css.
   ========================================================================== */

.settings-body {
  overflow-y: auto;
  height: auto;
  min-height: 100%;
}

.settings-page {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.settings-topbar {
  height: var(--header-h);
  min-height: var(--header-h);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--sp-6);
  background: var(--bg-canvas);
  box-shadow: 0 1px 0 var(--border-hairline);
  position: relative;
  z-index: 1;
}

.settings-main {
  flex: 1;
  display: flex;
  justify-content: center;
  padding: 8vh var(--sp-6) calc(var(--sp-6) * 2);
  background:
    radial-gradient(ellipse 900px 650px at 25% 0%, rgba(110, 86, 207, 0.30), transparent 60%),
    radial-gradient(ellipse 700px 550px at 90% 25%, rgba(156, 129, 245, 0.14), transparent 55%),
    var(--bg-surface);
}

.settings-card {
  width: 100%;
  max-width: 760px;
  background: rgba(22, 18, 36, 0.6);
  border: 1px solid rgba(110, 86, 207, 0.5);
  border-radius: var(--radius-lg);
  padding: var(--sp-6);
}

.settings-card__title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 var(--sp-5);
}

.settings-section {
  padding: var(--sp-5) 0;
  border-top: 1px solid var(--border-hairline);
}
.settings-section:first-of-type {
  border-top: none;
  padding-top: 0;
}

.settings-section__title {
  font-size: var(--fs-md);
  font-weight: 700;
  margin: 0 0 var(--sp-1);
}

.settings-section__desc {
  font-size: var(--fs-sm);
  color: var(--text-muted);
  margin: 0 0 var(--sp-4);
}

.settings-profile-row {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  margin-bottom: var(--sp-5);
}

.settings-link {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--highlight);
}
.settings-link:hover { text-decoration: underline; }

.settings-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-4);
}

.settings-section .field { margin-bottom: 0; }
.settings-section > .field + .field { margin-top: var(--sp-4); }

.form-success {
  font-size: var(--fs-sm);
  color: var(--online);
  background: rgba(74, 222, 128, 0.1);
  border: 1px solid rgba(74, 222, 128, 0.3);
  border-radius: var(--radius-sm);
  padding: var(--sp-3);
  margin: var(--sp-5) 0 0;
}

.settings-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--sp-4);
  margin-top: var(--sp-5);
}

.settings-save { flex: 0 0 auto; padding: 0 var(--sp-6); }

.btn-secondary {
  height: 46px;
  padding: 0 var(--sp-5);
  border-radius: var(--radius-sm);
  background: var(--bg-surface-raised);
  border: 1px solid var(--border-hairline);
  color: var(--text-primary);
  font-size: var(--fs-base);
  font-weight: 700;
  transition: background var(--duration-fast) var(--ease-standard);
}
.btn-secondary:hover { background: var(--bg-canvas); }

.settings-danger {
  margin-top: var(--sp-6);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--border-hairline);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
}

.settings-danger__title {
  font-size: var(--fs-base);
  font-weight: 700;
  color: var(--danger);
  margin: 0 0 4px;
}

.settings-danger__desc {
  font-size: var(--fs-xs);
  color: var(--text-muted);
  margin: 0;
  max-width: 40ch;
}

.btn-danger {
  flex-shrink: 0;
  height: 44px;
  padding: 0 var(--sp-5);
  border-radius: var(--radius-sm);
  background: rgba(229, 96, 107, 0.1);
  border: 1px solid rgba(229, 96, 107, 0.35);
  color: var(--danger);
  font-size: var(--fs-sm);
  font-weight: 700;
  transition: background var(--duration-fast) var(--ease-standard);
}
.btn-danger:hover { background: rgba(229, 96, 107, 0.2); }

@media (max-width: 640px) {
  .settings-main { padding-top: 6vh; }
  .settings-card { padding: var(--sp-5); }
  .settings-grid { grid-template-columns: 1fr; }
  .settings-actions { flex-direction: column-reverse; align-items: stretch; }
  .settings-danger { flex-direction: column; align-items: flex-start; }
}

/* ========================================================================== */
/* Modals */
/* ========================================================================== */
.modal-overlay {
  position: fixed; top: 0; left: 0; width: 100vw; height: 100vh;
  background: rgba(0,0,0,0.8);
  display: flex; align-items: center; justify-content: center;
  z-index: 1000;
}
.modal-overlay[hidden] { display: none; }
.modal {
  background: var(--bg-surface); padding: var(--sp-6); border-radius: var(--radius-lg);
  width: 100%; max-width: 400px;
  border: 1px solid var(--border-hairline);
}
.modal__title { font-size: var(--fs-lg); font-weight: 700; margin-bottom: var(--sp-2); }
.modal__body { color: var(--text-secondary); font-size: var(--fs-sm); }

/* ========================================================================== */
/* Welcome Empty States */
/* ========================================================================== */
.sidebar-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: var(--sp-6) var(--sp-5);
  flex: 1;
  min-height: 300px;
  text-align: center;
  position: relative;
}
.sidebar-empty[hidden] { display: none; }

.sidebar-empty__content {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: var(--sp-6);
}

.sidebar-empty__icon {
  width: 68px;
  height: 68px;
  border-radius: var(--radius-full);
  background: rgba(110, 86, 207, 0.15);
  border: 1px solid rgba(156, 129, 245, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--sp-4);
  box-shadow: 0 0 24px rgba(110, 86, 207, 0.25);
}

.sidebar-empty__title {
  font-size: var(--fs-lg);
  font-weight: 800;
  margin: 0 0 var(--sp-2);
  color: var(--text-primary);
}

.sidebar-empty__desc {
  font-size: var(--fs-sm);
  color: var(--text-muted);
  max-width: 240px;
  margin: 0;
  line-height: 1.5;
}

.sidebar-empty__arrow-wrap {
  position: absolute;
  bottom: 78px;
  right: 28px;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  pointer-events: none;
  z-index: 5;
}

.sidebar-empty__hint {
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--highlight);
  background: rgba(30, 24, 54, 0.92);
  border: 1px solid rgba(156, 129, 245, 0.4);
  padding: 6px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 4px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.4);
  white-space: nowrap;
}

.sidebar-empty__arrow {
  width: 64px;
  height: 64px;
  filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.4));
}

.chat-empty {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--sp-6);
  text-align: center;
}
.chat-empty[hidden] { display: none; }

.chat-empty__content {
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 380px;
}

.chat-empty__badge {
  width: 88px;
  height: 88px;
  border-radius: var(--radius-full);
  background: rgba(110, 86, 207, 0.12);
  border: 1px solid rgba(110, 86, 207, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--sp-5);
  box-shadow: 0 0 32px rgba(110, 86, 207, 0.2);
}

.chat-empty__content h2 {
  font-size: var(--fs-xl);
  font-weight: 800;
  margin: 0 0 var(--sp-2);
}

.chat-empty__content p {
  font-size: var(--fs-sm);
  color: var(--text-muted);
  line-height: 1.5;
  margin: 0 0 var(--sp-4);
}

/* ==========================================================================
   Skeleton screens
   ========================================================================== */
@keyframes skeleton-shimmer {
  0%   { background-position: -600px 0; }
  100% { background-position:  600px 0; }
}

/* Base shimmer surface — applied to every skeleton shape */
.skeleton-line,
.skeleton-circle,
.skeleton-bubble {
  background: linear-gradient(
    90deg,
    var(--bg-surface-raised) 25%,
    rgba(241, 238, 249, 0.07) 50%,
    var(--bg-surface-raised) 75%
  );
  background-size: 1200px 100%;
  animation: skeleton-shimmer 1.6s ease-in-out infinite;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

/* Circle avatar placeholder */
.skeleton-circle {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
}
.skeleton-circle--md {
  width: 44px;
  height: 44px;
}

/* ── Sidebar skeleton ────────────────────────────────── */
.sidebar-skeleton {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: var(--sp-2) var(--sp-3);
}
.sidebar-skeleton[hidden] { display: none !important; }

.skeleton-conv-item {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-3);
  border-radius: var(--radius-md);
}

.skeleton-conv-item__lines {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.skeleton-line {
  height: 12px;
  border-radius: var(--radius-full);
}

/* ── Chat panel skeleton ─────────────────────────────── */
.chat-skeleton {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
}
.chat-skeleton[hidden] { display: none !important; }

.chat-skeleton__header {
  height: var(--header-h);
  min-height: var(--header-h);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: 0 var(--sp-5);
  background: var(--bg-surface-raised);
  border-bottom: 1px solid rgba(110, 86, 207, 0.25);
}

.chat-skeleton__lines {
  display: flex;
  flex-direction: column;
}

.chat-skeleton__thread {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  padding: var(--sp-6);
  overflow: hidden;
}

/* Bubble-shaped skeleton rows */
.skeleton-bubble {
  height: 42px;
  border-radius: var(--radius-lg);
}
.skeleton-bubble--in {
  align-self: flex-start;
  border-bottom-left-radius: var(--radius-sm);
}
.skeleton-bubble--out {
  align-self: flex-end;
  border-bottom-right-radius: var(--radius-sm);
}