* {
  box-sizing: border-box;
}

:root {
  --bg: #f3f6fb;
  --surface: rgba(255, 255, 255, 0.82);
  --surface-strong: #ffffff;
  --surface-muted: #eef3fb;
  --border: rgba(148, 163, 184, 0.22);
  --text: #142033;
  --muted: #5f6f86;
  --title: #0f172a;
  --accent: #0f766e;
  --accent-strong: #115e59;
  --danger: #dc2626;
  --shadow: 0 24px 60px rgba(15, 23, 42, 0.14);
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI Variable", "Trebuchet MS", "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(15, 118, 110, 0.12), transparent 32%),
    radial-gradient(circle at top right, rgba(59, 130, 246, 0.12), transparent 28%),
    linear-gradient(180deg, #f8fbff 0%, #eef4fb 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.55) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.55) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.28;
  pointer-events: none;
}

#login {
  display: flex;
  min-height: 100dvh;
  justify-content: center;
  align-items: center;
  padding: 24px;
}

.login-shell,
.page-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.login-shell {
  display: grid;
  justify-items: center;
  gap: 18px;
}

.brand-badge,
.eyebrow,
.header-kicker {
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-size: 12px;
  font-weight: 700;
}

.brand-badge {
  padding: 10px 16px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(255, 255, 255, 0.9);
  color: var(--accent-strong);
  box-shadow: 0 12px 30px rgba(15, 23, 42, 0.08);
}

.card,
.chat-container,
.users-panel,
.chat {
  background: var(--surface);
  backdrop-filter: blur(18px);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.card {
  width: min(100%, 460px);
  padding: 36px;
  border-radius: 28px;
  text-align: left;
}

.card h1,
.users-panel h1,
.chat-header h2 {
  margin: 0;
  color: var(--title);
}

.card h1 {
  margin-top: 8px;
  font-size: clamp(2rem, 3vw, 2.6rem);
  line-height: 1.05;
}

.card-copy,
.panel-copy,
.note {
  color: var(--muted);
  line-height: 1.6;
}

.card-copy {
  margin: 14px 0 20px;
}

input {
  width: 100%;
  padding: 15px 18px;
  margin: 0;
  border-radius: 16px;
  border: 1px solid rgba(148, 163, 184, 0.28);
  background: rgba(255, 255, 255, 0.92);
  font-size: 16px;
  color: var(--text);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input:focus {
  border-color: rgba(15, 118, 110, 0.52);
  box-shadow: 0 0 0 4px rgba(15, 118, 110, 0.12);
}

button {
  padding: 14px 18px;
  border: none;
  border-radius: 16px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-strong) 100%);
  color: white;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, opacity 0.18s ease;
}

button:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 30px rgba(15, 118, 110, 0.22);
}

button:active {
  transform: translateY(0);
}

button:disabled,
input:disabled {
  cursor: not-allowed;
  opacity: 0.62;
}

button:disabled:hover {
  transform: none;
  box-shadow: none;
}

.card button {
  width: 100%;
  margin-top: 14px;
}

.note {
  margin: 14px 0 0;
  font-size: 14px;
}

.page-shell {
  padding: 24px 0;
}

.chat-container {
  display: flex;
  flex-direction: column;
  height: calc(100dvh - 48px);
  max-height: 920px;
  border-radius: 30px;
  overflow: hidden;
}

.chat-header {
  padding: 22px 24px;
  background: rgba(255, 255, 255, 0.72);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.header-kicker {
  margin: 0 0 6px;
  color: var(--accent-strong);
}

.chat-header h2 {
  font-size: 1.25rem;
}

.header-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border-radius: 999px;
  background: var(--surface-muted);
  color: var(--muted);
  font-weight: 700;
  white-space: nowrap;
}

.status-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #22c55e;
  box-shadow: 0 0 0 4px rgba(34, 197, 94, 0.16);
}

#messages {
  flex: 1;
  padding: 24px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
  scroll-behavior: smooth;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.48) 0%, rgba(240, 246, 255, 0.88) 100%);
}

#messages:empty::before {
  content: "No messages yet. Start the conversation to see the thread appear here.";
  max-width: 380px;
  padding: 16px 18px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.7);
  border: 1px dashed rgba(148, 163, 184, 0.35);
  color: var(--muted);
  line-height: 1.6;
}

.message {
  max-width: min(78%, 720px);
  padding: 14px 16px;
  border-radius: 22px;
  line-height: 1.55;
  box-shadow: 0 14px 30px rgba(15, 23, 42, 0.08);
  animation: bubble-in 0.2s ease;
}

.message-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 6px;
  font-size: 12px;
  font-weight: 700;
}

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

.user {
  align-self: flex-end;
  background: linear-gradient(135deg, #0f766e 0%, #0f9b8e 100%);
  color: #ffffff;
  border-bottom-right-radius: 8px;
}

.user .message-meta {
  color: rgba(255, 255, 255, 0.82);
}

.admin {
  align-self: flex-start;
  background: rgba(255, 255, 255, 0.88);
  color: var(--text);
  border: 1px solid rgba(148, 163, 184, 0.18);
  border-bottom-left-radius: 8px;
}

.admin .message-meta {
  color: var(--muted);
}

.input-area {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 18px 20px 20px;
  background: rgba(255, 255, 255, 0.76);
  border-top: 1px solid var(--border);
}

.input-area input {
  flex: 1;
  border-radius: 999px;
  background: var(--surface-strong);
}

.input-area button {
  min-width: 110px;
  border-radius: 999px;
}

.menu-btn {
  display: none;
  width: calc(100% - 32px);
  margin: 16px auto 0;
}

.admin-container {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 20px;
  min-height: calc(100dvh - 48px);
  max-height: 920px;
}

.users-panel {
  border-radius: 30px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.users-panel-header {
  padding: 26px 22px 18px;
  border-bottom: 1px solid var(--border);
}

.users-panel-header .eyebrow {
  margin: 0 0 8px;
  color: var(--accent-strong);
}

.users-panel h1 {
  font-size: 1.8rem;
}

.panel-copy {
  margin: 12px 0 0;
}

.users {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 16px;
  overflow-y: auto;
  flex: 1;
}

.user-item {
  padding: 14px 14px 14px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(148, 163, 184, 0.18);
  color: var(--text);
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}

.user-item:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 30px rgba(15, 23, 42, 0.08);
  border-color: rgba(15, 118, 110, 0.24);
}

.user-item.active {
  background: rgba(15, 118, 110, 0.12);
  border-color: rgba(15, 118, 110, 0.26);
}

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

.user-name {
  display: block;
  font-weight: 700;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.user-preview {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  color: var(--muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.delete-btn {
  background: rgba(220, 38, 38, 0.12);
  color: var(--danger);
  border: 1px solid rgba(220, 38, 38, 0.16);
  padding: 9px 12px;
  border-radius: 12px;
  box-shadow: none;
}

.delete-btn:hover {
  box-shadow: none;
  background: rgba(220, 38, 38, 0.16);
}

.chat {
  display: flex;
  flex-direction: column;
  min-height: 0;
  border-radius: 30px;
  overflow: hidden;
}

@keyframes bubble-in {
  from {
    opacity: 0;
    transform: translateY(6px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 768px) {
  .page-shell {
    width: calc(100% - 20px);
    padding: 12px 0 20px;
  }

  .card {
    padding: 28px 22px;
    border-radius: 24px;
  }

  .menu-btn {
    display: block;
  }

  .admin-container {
    display: block;
    min-height: auto;
    max-height: none;
  }

  .users-panel {
    position: relative;
    margin-bottom: 14px;
  }

  .users {
    display: none;
    position: absolute;
    width: 100%;
    top: calc(100% + 8px);
    left: 0;
    z-index: 4;
    max-height: 320px;
    background: rgba(255, 255, 255, 0.98);
    border-radius: 22px;
    box-shadow: var(--shadow);
  }

  .users.active {
    display: flex;
    flex-direction: column;
  }

  .users-panel-header {
    padding: 20px 18px;
  }

  .chat-container,
  .chat {
    height: calc(100dvh - 110px);
    border-radius: 24px;
  }

  .chat-header,
  .input-area {
    padding-left: 16px;
    padding-right: 16px;
  }

  #messages {
    padding: 18px 16px;
  }

  .message {
    max-width: 88%;
  }

  .input-area {
    gap: 10px;
  }

  .input-area button {
    min-width: 88px;
  }
}