:root {
  --yellow: #f5d76e;
  --yellow-deep: #e8c547;
  --white: #ffffff;
  --gray-light: #e8e8e8;
  --gray: #bdbdbd;
  --gray-dark: #6e6e6e;
  --black: #111111;
  --error-bg: #fff0f0;
  --ok-bg: #f0fff0;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
}

body {
  font-family: "Segoe UI", "Helvetica Neue", Helvetica, Arial, sans-serif;
  background: var(--white);
  color: var(--black);
  line-height: 1.5;
  min-height: 100vh;
}

.wrap {
  width: min(960px, 100% - 2rem);
  margin-inline: auto;
}

.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;
}

.top {
  background: var(--yellow);
  border-bottom: 2px solid var(--black);
  padding: 1.25rem 0;
}

.top-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.75rem 1.25rem;
}

.logout-link {
  color: var(--black);
  font-weight: 700;
  text-decoration: underline;
  padding: 0.55rem 0.85rem;
  border: 2px solid var(--black);
  background: var(--white);
  align-self: center;
  white-space: nowrap;
}

.logout-link:hover {
  background: var(--yellow-deep);
}

.login-main {
  padding: 2rem 0 2.5rem;
  display: grid;
  place-items: start stretch;
}

.login-panel {
  max-width: 28rem;
  width: 100%;
  margin-inline: auto;
}

.login-panel .status {
  margin-bottom: 1rem;
}

.brand {
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--black);
}

.tag {
  margin-top: 0.25rem;
  color: var(--black);
  font-size: 0.95rem;
}

main {
  padding: 1.5rem 0 2.5rem;
  display: grid;
  gap: 1.25rem;
}

.tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 2px solid var(--black);
  background: var(--gray-light);
}

.tab-btn {
  margin-top: 0;
  border: none;
  border-right: 2px solid var(--black);
  background: var(--gray-light);
  font-weight: 700;
  padding: 0.85rem 1rem;
}

.tab-btn:last-child {
  border-right: none;
}

.tab-btn:hover {
  background: var(--yellow);
}

.tab-btn.active {
  background: var(--yellow);
}

.tab-panel {
  display: none;
  gap: 1.25rem;
}

.tab-panel.is-active {
  display: grid;
}

.multi-picker {
  position: relative;
  border: 2px solid var(--black);
  background: var(--white);
  padding: 0.4rem;
  margin-bottom: 0.85rem;
  min-height: 3rem;
  cursor: text;
}

.multi-picker:focus-within {
  outline: 2px solid var(--yellow-deep);
  outline-offset: 0;
  background: #fffef6;
}

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  border: 2px solid var(--black);
  background: var(--yellow);
  color: var(--black);
  padding: 0.25rem 0.45rem;
  font-size: 0.9rem;
  font-weight: 600;
  max-width: 100%;
}

.chip-label {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chip-remove {
  margin: 0;
  padding: 0;
  width: 1.35rem;
  height: 1.35rem;
  min-width: 1.35rem;
  border: 2px solid var(--black);
  background: var(--white);
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  flex-shrink: 0;
}

.chip-remove:hover {
  background: var(--error-bg);
}

.picker-input {
  border: none;
  outline: none;
  width: 100%;
  min-width: 10rem;
  padding: 0.45rem 0.35rem;
  background: transparent;
  margin-top: 0.25rem;
}

.picker-input:focus {
  outline: none;
  background: transparent;
}

.picker-dropdown {
  list-style: none;
  position: absolute;
  left: -2px;
  right: -2px;
  top: calc(100% + 2px);
  z-index: 20;
  max-height: 220px;
  overflow: auto;
  border: 2px solid var(--black);
  background: var(--white);
  margin: 0;
  padding: 0;
}

.picker-option {
  margin: 0;
  width: 100%;
  text-align: left;
  border: none;
  border-bottom: 1px solid var(--gray);
  border-radius: 0;
  background: var(--white);
  font-weight: 500;
  padding: 0.65rem 0.85rem;
}

.picker-option:hover,
.picker-option.active {
  background: var(--yellow);
}

.picker-option:disabled {
  background: var(--gray-light);
  color: var(--gray-dark);
  cursor: default;
}

.history-list {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.75rem;
}

.history-item {
  border: 2px solid var(--black);
  background: var(--white);
  padding: 0.85rem;
  display: grid;
  gap: 0.55rem;
}

.history-title {
  font-weight: 700;
  color: var(--black);
}

.history-meta {
  font-size: 0.85rem;
  color: var(--gray-dark);
}

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

.history-actions a,
.history-actions .dl-btn {
  display: inline-block;
  border: 2px solid var(--black);
  background: var(--yellow);
  color: var(--black);
  text-decoration: none;
  font-weight: 700;
  padding: 0.45rem 0.75rem;
  margin: 0;
  width: auto;
}

.history-actions a:hover,
.history-actions .dl-btn:hover {
  background: var(--yellow-deep);
}

.panel {
  background: var(--white);
  border: 2px solid var(--black);
  padding: 1.25rem;
}

.panel h1,
.panel h2 {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--black);
}

.hint {
  color: var(--black);
  margin-bottom: 1.25rem;
  font-size: 0.95rem;
}

.hint a {
  color: var(--black);
  text-decoration: underline;
}

form {
  display: grid;
  gap: 0.5rem;
}

label {
  font-weight: 600;
  color: var(--black);
  margin-top: 0.5rem;
}

input,
textarea,
button {
  border: 2px solid var(--black);
  border-radius: 0;
  font: inherit;
  color: var(--black);
  background: var(--white);
  padding: 0.75rem 0.85rem;
  width: 100%;
}

input:focus,
textarea:focus {
  outline: 2px solid var(--yellow-deep);
  outline-offset: 0;
  background: #fffef6;
}

textarea {
  resize: vertical;
  min-height: 8rem;
}

button {
  margin-top: 1rem;
  background: var(--yellow);
  font-weight: 700;
  cursor: pointer;
  transition: background 0.15s ease;
}

button:hover {
  background: var(--yellow-deep);
}

button:active {
  background: var(--gray);
}

button:disabled {
  background: var(--gray-light);
  cursor: not-allowed;
}

.status {
  margin-top: 1rem;
  padding: 0.85rem;
  border: 2px solid var(--black);
  background: var(--gray-light);
  color: var(--black);
  white-space: pre-wrap;
}

.status.ok {
  background: var(--ok-bg);
}

.status.err {
  background: var(--error-bg);
}

.note {
  background: var(--gray-light);
}

.note ul {
  padding-left: 1.25rem;
}

.note li + li {
  margin-top: 0.4rem;
}

.contacts-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.contacts-head h2 {
  margin-bottom: 0;
}

.hint.tight {
  margin-bottom: 0.75rem;
}

button.secondary {
  margin-top: 0;
  width: auto;
  background: var(--white);
  font-weight: 600;
  padding: 0.55rem 0.85rem;
}

button.secondary:hover {
  background: var(--yellow);
}

.contacts {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.contact-btn {
  margin-top: 0;
  text-align: left;
  background: var(--white);
  font-weight: 500;
}

.contact-btn:hover {
  background: var(--yellow);
}

.dropzone {
  border: 2px dashed var(--black);
  background: var(--gray-light);
  padding: 1.75rem 1rem;
  text-align: center;
  cursor: pointer;
  margin-bottom: 0.75rem;
}

.dropzone.dragover {
  background: var(--yellow);
}

.drop-title {
  font-weight: 700;
  color: var(--black);
}

.drop-sub {
  margin-top: 0.35rem;
  color: var(--gray-dark);
  font-size: 0.9rem;
}

.file-label {
  margin-bottom: 0.5rem;
  font-weight: 600;
}

#quiz-send-btn {
  margin-top: 0.5rem;
}

.foot {
  padding: 1rem 0 2rem;
  color: var(--gray-dark);
  font-size: 0.85rem;
  border-top: 1px solid var(--gray);
}

.chat-section {
  background: var(--white);
}

.chat-sidebar-tools {
  padding: 0.65rem;
  border-bottom: 2px solid var(--black);
  background: var(--white);
}

.chat-sidebar-tools input {
  width: 100%;
  padding: 0.55rem 0.65rem;
  border: 2px solid var(--black);
  border-radius: 0;
  background: var(--white);
  color: var(--black);
  font: inherit;
}

.chat-layout {
  display: grid;
  grid-template-columns: minmax(220px, 300px) 1fr;
  gap: 0;
  border: 2px solid var(--black);
  min-height: 520px;
}

.chat-sidebar {
  background: var(--gray-light);
  border-right: 2px solid var(--black);
  overflow: auto;
  max-height: 620px;
  display: flex;
  flex-direction: column;
}

.chat-list {
  list-style: none;
  padding: 0;
  margin: 0;
  flex: 1;
}

.chat-list-btn {
  margin-top: 0;
  width: 100%;
  text-align: left;
  background: var(--gray-light);
  font-weight: 500;
  border: none;
  border-bottom: 1px solid var(--gray);
  border-radius: 0;
  display: grid;
  gap: 0.15rem;
  padding: 0.75rem 0.85rem;
}

.chat-list-btn:hover {
  background: var(--yellow);
}

.chat-list-btn.active {
  background: var(--yellow);
  font-weight: 700;
}

.chat-list-title {
  font-weight: 700;
  color: var(--black);
}

.chat-list-preview {
  font-size: 0.85rem;
  color: var(--black);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.chat-list-time {
  font-size: 0.75rem;
  color: var(--gray-dark);
}

.chat-main {
  display: flex;
  flex-direction: column;
  min-height: 520px;
  background: var(--white);
}

.chat-thread-header {
  padding: 0.75rem 1rem;
  border-bottom: 2px solid var(--black);
  font-weight: 700;
  background: var(--yellow);
}

.chat-messages {
  flex: 1;
  overflow: auto;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  max-height: none;
  min-height: 280px;
  background: var(--white);
}

.chat-placeholder {
  margin: auto;
  text-align: center;
  color: var(--gray-dark);
}

.msg {
  display: flex;
  flex-direction: column;
  max-width: 85%;
}

.msg-in {
  align-self: flex-start;
}

.msg-out {
  align-self: flex-end;
  align-items: flex-end;
}

.msg-bubble {
  border: 2px solid var(--black);
  padding: 0.65rem 0.85rem;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--black);
}

.msg-in .msg-bubble {
  background: var(--gray-light);
}

.msg-out .msg-bubble {
  background: var(--yellow);
}

.msg-meta {
  font-size: 0.75rem;
  color: var(--gray-dark);
  margin-top: 0.2rem;
}

.chat-compose {
  display: grid;
  gap: 0.5rem;
  padding: 0.75rem;
  border-top: 2px solid var(--black);
  background: var(--gray-light);
}

.chat-compose textarea {
  min-height: 4.5rem;
  margin: 0;
}

.chat-compose button {
  margin-top: 0;
}

.chat-main > .status {
  margin: 0.75rem;
}

@media (max-width: 720px) {
  .chat-layout {
    grid-template-columns: 1fr;
    min-height: 0;
  }

  .chat-sidebar {
    border-right: none;
    border-bottom: 2px solid var(--black);
    max-height: 240px;
  }

  .chat-main {
    min-height: 420px;
  }
}

@media (max-width: 480px) {
  .wrap {
    width: calc(100% - 1.25rem);
  }

  .panel {
    padding: 1rem;
  }

  input,
  textarea,
  button {
    padding: 0.9rem 0.85rem;
    font-size: 1rem;
  }
}