:root {
  color-scheme: light;
  --bg: #f5f8fd;
  --panel: #ffffff;
  --panel-soft: #f8fbff;
  --line: #dbe6f3;
  --line-strong: #c7d6e8;
  --text: #111827;
  --muted: #738197;
  --primary: #1f5bea;
  --primary-2: #3b82f6;
  --primary-soft: #eaf2ff;
  --primary-line: #94b8ff;
  --radius: 14px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background:
    radial-gradient(circle at 78% 22%, rgba(73, 135, 255, 0.18), transparent 34%),
    radial-gradient(circle at 40% 18%, rgba(175, 205, 255, 0.18), transparent 30%),
    linear-gradient(180deg, #f8fbff 0%, #ffffff 48%, #f6f9fe 100%);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

h1,
h2,
h3,
p {
  margin: 0;
  letter-spacing: 0;
}

.lucide-icon {
  display: block;
}

.site-header {
  position: relative;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 60px;
  padding: 10px 30px;
  border-bottom: 1px solid rgba(203, 213, 225, 0.72);
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(18px);
  box-shadow: 0 10px 36px rgba(30, 64, 175, 0.06);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: inherit;
  text-decoration: none;
}

.brand-logo {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 11px;
  background: linear-gradient(135deg, #1d4ed8 0%, #2f7bff 100%);
  color: white;
  box-shadow: 0 12px 26px rgba(37, 99, 235, 0.26);
}

.brand-copy {
  display: grid;
  gap: 2px;
}

.brand-copy strong {
  color: #0f172a;
  font-size: 20px;
  font-weight: 900;
  line-height: 1.1;
}

.brand-copy small {
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.site-slogan {
  position: absolute;
  left: 50%;
  max-width: min(620px, 44vw);
  transform: translateX(-50%);
  color: #4f5f78;
  font-size: 15px;
  font-weight: 850;
  line-height: 1.4;
  overflow: hidden;
  text-align: center;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.site-nav {
  position: relative;
  display: flex;
  align-items: center;
  gap: 12px;
}

.profile-button {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 38px;
  border: 1px solid rgba(203, 213, 225, 0.9);
  border-radius: 13px;
  background: rgba(255, 255, 255, 0.82);
  color: #233047;
  padding: 0 13px;
  font-size: 13px;
  font-weight: 800;
  box-shadow: 0 8px 18px rgba(15, 23, 42, 0.04);
}

.profile-button {
  border-radius: 999px;
  padding-left: 7px;
}

.profile-badge {
  display: grid;
  width: 30px;
  height: 30px;
  place-items: center;
  border-radius: 999px;
  background: linear-gradient(135deg, #2563eb, #60a5fa);
  color: white;
}

#profileLabel {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.quota-pill {
  display: inline-flex;
  align-items: center;
  min-height: 22px;
  border-radius: 999px;
  background: #eef5ff;
  color: var(--primary);
  padding: 0 8px;
  font-size: 12px;
  font-weight: 900;
  white-space: nowrap;
}

.account-menu[hidden] {
  display: none;
}

.account-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 10;
  width: 146px;
  display: grid;
  gap: 4px;
  padding: 8px;
  border: 1px solid rgba(203, 213, 225, 0.9);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 18px 42px rgba(15, 23, 42, 0.14);
  backdrop-filter: blur(14px);
}

.account-menu button {
  min-height: 36px;
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: #1f2a3b;
  padding: 0 10px;
  text-align: left;
  font-size: 13px;
  font-weight: 850;
}

.account-menu button:hover {
  background: #eef5ff;
  color: var(--primary);
}

.auth-modal[hidden] {
  display: none;
}

.auth-modal {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  padding: 24px;
}

.auth-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.22);
  backdrop-filter: blur(4px);
}

.auth-card {
  position: relative;
  z-index: 1;
  width: min(380px, 100%);
  display: grid;
  gap: 14px;
  padding: 24px;
  border: 1px solid rgba(203, 213, 225, 0.9);
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 28px 72px rgba(15, 23, 42, 0.18);
}

.auth-close {
  position: absolute;
  top: 12px;
  right: 14px;
  border: 0;
  background: transparent;
  color: #64748b;
  font-size: 24px;
  line-height: 1;
}

.auth-card h2 {
  color: #0f172a;
  font-size: 22px;
  font-weight: 900;
}

.auth-note {
  color: #64748b;
  font-size: 13px;
  line-height: 1.6;
}

.auth-card form {
  display: grid;
  gap: 12px;
}

.auth-card [hidden] {
  display: none !important;
}

.auth-card label {
  display: grid;
  gap: 6px;
  color: #475569;
  font-size: 13px;
  font-weight: 800;
}

.auth-card input {
  min-height: 42px;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  background: white;
  color: var(--text);
  padding: 0 12px;
  font: inherit;
  outline: none;
}

.auth-card input:focus {
  border-color: #7ca7ff;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.sms-code-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
}

.sms-code-button {
  min-width: 104px;
  min-height: 42px;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  background: #f8fbff;
  color: var(--primary);
  font-size: 13px;
  font-weight: 850;
}

.sms-code-button:disabled {
  cursor: not-allowed;
  opacity: 0.62;
}

.auth-error {
  min-height: 18px;
  color: #dc2626;
  font-size: 13px;
  line-height: 1.4;
}

.auth-submit {
  min-height: 42px;
  border: 0;
  border-radius: 12px;
  background: linear-gradient(135deg, #1d4ed8, #2563eb);
  color: white;
  font-size: 15px;
  font-weight: 900;
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.22);
}

.auth-switch {
  border: 0;
  background: transparent;
  color: var(--primary);
  font-size: 13px;
  font-weight: 850;
}

.auth-actions {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}

.auth-forgot {
  border: 0;
  background: transparent;
  color: #64748b;
  font-size: 13px;
  font-weight: 850;
}

.account-card {
  width: min(520px, 100%);
}

.purchase-card {
  width: min(560px, 100%);
}

.support-card {
  width: min(560px, 100%);
  max-height: min(760px, calc(100vh - 48px));
  overflow-y: auto;
}

.account-row {
  min-height: 66px;
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: 14px;
  align-items: center;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.account-row span {
  color: #0f172a;
  font-size: 16px;
  font-weight: 850;
}

.account-row strong {
  color: #0f172a;
  font-size: 16px;
  font-weight: 800;
}

.inline-action {
  border: 0;
  background: transparent;
  color: var(--primary);
  padding: 0;
  font-size: 15px;
  font-weight: 850;
}

.change-phone-form[hidden],
.change-password-form[hidden],
.account-promo-form[hidden] {
  display: none;
}

.change-phone-form,
.change-password-form,
.account-promo-form {
  display: grid;
  gap: 12px;
}

.purchase-options {
  display: grid;
  gap: 12px;
}

.purchase-option-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 16px;
  align-items: center;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: linear-gradient(180deg, rgba(248, 251, 255, 0.96), rgba(255, 255, 255, 0.98));
}

.purchase-option-copy {
  display: grid;
  gap: 6px;
}

.purchase-option-copy strong {
  color: #0f172a;
  font-size: 18px;
  font-weight: 900;
}

.purchase-option-copy p {
  color: var(--primary);
  font-size: 16px;
  font-weight: 900;
}

.purchase-option-copy small {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.purchase-action {
  min-width: 96px;
}

.support-content {
  color: #334155;
  font-size: 15px;
  line-height: 1.75;
}

.support-content:empty {
  display: none;
}

.support-image {
  width: 100%;
  max-height: 320px;
  object-fit: contain;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #f8fbff;
}

.feedback-form {
  display: grid;
  gap: 12px;
}

.feedback-form textarea {
  min-height: 112px;
  resize: vertical;
}

.page-shell {
  flex: 1;
  min-height: calc(100vh - 60px);
  padding: 12px 30px 24px;
}

.site-footer {
  padding: 0 30px 18px;
  text-align: center;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
}

.site-footer a {
  color: inherit;
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--primary);
  text-decoration: underline;
}

.qa-panel {
  position: relative;
  width: 100%;
  height: calc(100vh - 96px);
  min-height: calc(100vh - 96px);
  margin: 0 auto;
}

.app-layout {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 12px;
  height: 100%;
  min-height: calc(100vh - 96px);
}

.filter-sidebar {
  align-self: start;
  display: grid;
  gap: 22px;
  margin-top: 0;
  padding: 26px 24px 24px;
  border: 1px solid rgba(203, 213, 225, 0.72);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.78);
  box-shadow: 0 22px 56px rgba(37, 99, 235, 0.08);
  backdrop-filter: blur(18px);
}

.filter-group {
  display: grid;
  gap: 14px;
}

.filter-group + .filter-group {
  margin-top: 12px;
}

.filter-title {
  color: var(--muted);
  font-size: 14px;
  font-weight: 850;
}

.chip-list {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  align-content: flex-start;
  gap: 10px;
}

.filter-chip {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 38px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.82);
  color: #283548;
  padding: 0 15px;
  font-size: 14px;
  font-weight: 800;
  box-shadow: 0 6px 18px rgba(15, 23, 42, 0.03);
}

.filter-chip.active {
  border-color: #7ca7ff;
  background: linear-gradient(135deg, #2563eb 0%, #4f8dff 100%);
  color: white;
  box-shadow: 0 12px 26px rgba(37, 99, 235, 0.22);
}

.filter-chip:disabled,
textarea:disabled,
.primary-button:disabled {
  cursor: not-allowed;
}

.filter-chip:disabled {
  opacity: 0.58;
  box-shadow: none;
}

.filter-chip.active:disabled {
  opacity: 0.72;
}

textarea:disabled {
  color: #64748b;
  opacity: 0.72;
}

.primary-button:disabled {
  opacity: 0.58;
  box-shadow: none;
}

.chip-icon {
  display: inline-flex;
}

.question-history {
  display: grid;
  gap: 12px;
  padding-top: 4px;
  border-top: 1px solid rgba(203, 213, 225, 0.68);
}

.history-title {
  color: var(--muted);
  font-size: 14px;
  font-weight: 850;
}

.history-list {
  display: grid;
  gap: 8px;
}

.history-item {
  width: 100%;
  display: block;
  border: 1px solid rgba(203, 213, 225, 0.74);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.68);
  color: #334155;
  padding: 10px 12px;
  text-align: left;
  font-size: 13px;
  font-weight: 750;
  line-height: 1.45;
  box-shadow: 0 8px 18px rgba(15, 23, 42, 0.03);
}

.history-item:hover {
  border-color: var(--primary-line);
  background: #f8fbff;
  color: #1e3a8a;
}

.history-item.active {
  border-color: #8db2ff;
  background: #eef5ff;
  color: #1d4ed8;
  box-shadow: 0 10px 24px rgba(37, 99, 235, 0.12);
}

.history-item:disabled {
  cursor: not-allowed;
  opacity: 0.58;
  box-shadow: none;
}

.history-item:disabled:hover {
  border-color: rgba(203, 213, 225, 0.74);
  background: rgba(255, 255, 255, 0.68);
  color: #334155;
}

.history-item strong {
  color: var(--primary);
  font-weight: 900;
}

.history-item span {
  overflow-wrap: anywhere;
}

.history-empty {
  color: #94a3b8;
  font-size: 13px;
  font-weight: 750;
  line-height: 1.5;
}

.qa-main {
  min-width: 0;
  height: 100%;
  min-height: calc(100vh - 96px);
  display: flex;
  flex-direction: column;
}

.answer-area {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 12px 0 18px;
}

.answer-body {
  width: 100%;
  margin: 0;
}

.welcome-hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-items: center;
  gap: 36px;
  min-height: 300px;
}

.welcome-copy {
  display: grid;
  justify-items: center;
  gap: 18px;
  text-align: center;
}

.welcome-copy h2 {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: #111827;
  font-size: 34px;
  font-weight: 950;
  line-height: 1.2;
}

.welcome-copy h2 span {
  color: var(--primary);
}

.welcome-copy h2 .lucide-icon {
  color: #4f83ff;
}

.welcome-copy p {
  color: #77849a;
  font-size: 17px;
  font-weight: 700;
}

.feature-strip {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 42px;
  margin-top: 16px;
}

.feature-item {
  display: grid;
  grid-template-columns: 42px auto;
  column-gap: 12px;
  row-gap: 2px;
  align-items: center;
  text-align: left;
}

.feature-item > span {
  display: grid;
  grid-row: span 2;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 14px;
  background: #eef5ff;
  color: var(--primary);
}

.feature-item strong {
  color: #1c2940;
  font-size: 14px;
  font-weight: 900;
}

.feature-item small {
  color: #79879d;
  font-size: 13px;
  font-weight: 700;
}

.composer-area {
  display: flex;
  justify-content: center;
  padding: 8px 0 0;
  background: transparent;
  position: static;
}

.composer-card {
  width: 100%;
  display: grid;
  gap: 14px;
  padding: 16px;
  border: 1px solid rgba(166, 190, 224, 0.86);
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.86);
  box-shadow: 0 20px 48px rgba(37, 99, 235, 0.09);
  backdrop-filter: blur(18px);
}

.teacher-picker {
  display: grid;
  gap: 8px;
}

.teacher-picker:empty {
  display: none;
}

.teacher-picker-hint {
  color: #68778f;
  font-size: 13px;
  font-weight: 800;
  line-height: 1.4;
}

.teacher-options {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.teacher-option {
  min-height: 34px;
  border: 1px solid rgba(148, 163, 184, 0.38);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.88);
  color: #334155;
  padding: 0 13px;
  font-size: 13px;
  font-weight: 850;
}

.teacher-option.active {
  border-color: rgba(37, 99, 235, 0.58);
  background: var(--primary);
  color: #ffffff;
  box-shadow: 0 10px 24px rgba(37, 99, 235, 0.2);
}

.teacher-option:disabled {
  cursor: not-allowed;
  opacity: 0.55;
  pointer-events: none;
  box-shadow: none;
}

.teacher-option.active:disabled {
  opacity: 0.65;
}

.ask-area {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  align-items: end;
}

textarea {
  width: 100%;
  height: 56px;
  min-height: 56px;
  max-height: 150px;
  resize: vertical;
  border: 0;
  border-radius: 0;
  background: transparent;
  color: var(--text);
  padding: 0;
  font-size: 15px;
  line-height: 1.6;
  outline: none;
}

textarea::placeholder {
  color: #98a4b8;
  font-weight: 700;
}

.primary-button {
  display: grid;
  width: 46px;
  min-height: 46px;
  place-items: center;
  border: 0;
  border-radius: 999px;
  background: linear-gradient(135deg, #1d4ed8, #2563eb);
  color: white;
  padding: 0;
  box-shadow: 0 14px 28px rgba(37, 99, 235, 0.28);
}

.primary-button .lucide-icon {
  width: 20px;
  height: 20px;
}

.composer-controls {
  display: grid;
  gap: 12px;
}

.answer-toolbar {
  display: grid;
  gap: 8px;
  justify-items: start;
}

.answer-mode-hint {
  color: #68778f;
  font-size: 13px;
  font-weight: 800;
  line-height: 1.4;
}

.answer-mode-hint span {
  margin-left: 14px;
}

.answer-modes {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: flex-start;
}

.answer-modes .filter-chip {
  min-height: 34px;
  padding: 0 13px;
  font-size: 13px;
}

.markdown-answer {
  display: grid;
  gap: 10px;
  color: #283548;
  line-height: 1.8;
}

.markdown-answer h3 {
  margin: 6px 0 0;
  color: #172033;
  font-size: 18px;
  line-height: 1.35;
}

.markdown-answer p {
  color: #283548;
  line-height: 1.8;
}

.markdown-answer ol,
.markdown-answer ul {
  margin: 0;
  padding-left: 24px;
}

.markdown-answer li + li {
  margin-top: 4px;
}

.markdown-answer strong {
  color: var(--primary);
  font-weight: 850;
}

.teacher-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

.teacher-tab {
  min-height: 34px;
  border: 1px solid rgba(148, 163, 184, 0.38);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.88);
  color: #334155;
  padding: 0 13px;
  font-size: 13px;
  font-weight: 850;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.teacher-tab.active {
  border-color: rgba(37, 99, 235, 0.58);
  background: var(--primary);
  color: #ffffff;
  box-shadow: 0 10px 24px rgba(37, 99, 235, 0.2);
}

.teacher-tab.failed:not(.active) {
  color: #991b1b;
}

.teacher-tab small {
  font-size: 11px;
  font-weight: 800;
  opacity: 0.8;
}

.status-note {
  margin-bottom: 12px;
  padding: 10px 12px;
  border: 1px solid #bfdbfe;
  border-radius: 10px;
  background: #eff6ff;
  color: #1e3a8a;
  font-size: 13px;
  line-height: 1.55;
}

.answer-status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.answer-status span {
  min-width: 0;
}

.regenerate-button {
  flex: 0 0 auto;
  min-height: 30px;
  border: 1px solid rgba(37, 99, 235, 0.35);
  border-radius: 999px;
  background: #ffffff;
  color: var(--primary);
  padding: 0 12px;
  font-size: 12px;
  font-weight: 850;
}

.regenerate-button:hover {
  border-color: rgba(37, 99, 235, 0.68);
  background: #dbeafe;
}

.status-note.error {
  border-color: #fecaca;
  background: #fef2f2;
  color: #991b1b;
}

.answer-skeleton {
  display: grid;
  position: relative;
  overflow: hidden;
  gap: 18px;
  min-height: 360px;
  padding: 22px 24px;
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: 16px;
  background:
    linear-gradient(135deg, rgba(239, 246, 255, 0.96) 0%, rgba(219, 234, 254, 0.78) 100%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9);
}

.answer-skeleton::before {
  content: "";
  position: absolute;
  inset: 0;
  transform: translateX(-115%);
  background: linear-gradient(105deg, transparent 20%, rgba(255, 255, 255, 0.72) 46%, transparent 70%);
  animation: skeleton-sweep 1.65s cubic-bezier(0.4, 0, 0.2, 1) infinite;
  pointer-events: none;
}

.skeleton-block {
  display: grid;
  position: relative;
  z-index: 1;
  gap: 12px;
  align-content: start;
}

.skeleton-heading {
  display: flex;
  align-items: center;
  gap: 10px;
}

.skeleton-dot {
  width: 12px;
  height: 12px;
  border-radius: 999px;
  background: #3b82f6;
  box-shadow: 0 0 0 6px rgba(59, 130, 246, 0.12);
  animation: skeleton-pulse 1.35s ease-in-out infinite;
}

.skeleton-line {
  height: 18px;
  width: 72%;
  border-radius: 999px;
  background: linear-gradient(90deg, #c7d9ff 0%, #eff6ff 44%, #b8ccff 100%);
  box-shadow: 0 8px 22px rgba(37, 99, 235, 0.08);
  opacity: 0.92;
  animation: skeleton-pulse 1.45s ease-in-out infinite;
}

.skeleton-block:nth-child(2) .skeleton-line,
.skeleton-block:nth-child(2) .skeleton-dot {
  animation-delay: 0.18s;
}

.skeleton-title {
  width: 120px;
  height: 20px;
  background: linear-gradient(90deg, #7ea6ff 0%, #dbeafe 55%, #8fb3ff 100%);
}

.skeleton-title.short-title {
  width: 96px;
}

.skeleton-line.wide {
  width: 88%;
}

.skeleton-line.medium {
  width: 64%;
}

.skeleton-line.short {
  width: 46%;
}

@keyframes skeleton-sweep {
  0% {
    transform: translateX(-115%);
  }

  100% {
    transform: translateX(115%);
  }
}

@keyframes skeleton-pulse {
  0%,
  100% {
    opacity: 0.68;
    transform: scaleX(0.985);
  }

  50% {
    opacity: 1;
    transform: scaleX(1);
  }
}

.sources-list {
  width: 100%;
  margin: 16px 0 0;
}

.sources-title {
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.source-line {
  display: grid;
  gap: 4px;
  padding: 9px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.86);
  color: #475569;
  font-size: 13px;
  line-height: 1.5;
}

.source-line strong {
  color: #1f2a3b;
}

.source-line span {
  color: #64748b;
}

.source-line + .source-line {
  margin-top: 8px;
}

.copyright-note {
  margin-top: 10px;
  color: #64748b;
  font-size: 12px;
  line-height: 1.6;
}

.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;
}

@media (max-width: 960px) {
  .site-header {
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
  }

  .site-nav {
    width: auto;
    overflow: visible;
    padding-bottom: 0;
  }

  .site-slogan {
    display: none;
  }

  .app-layout {
    grid-template-columns: 1fr;
  }

  .filter-sidebar {
    margin-top: 0;
  }

  .answer-area {
    padding-top: 18px;
  }

  .composer-area {
    position: static;
  }

  .welcome-hero {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .site-header {
    padding: 8px 12px;
  }

  .brand-logo {
    width: 34px;
    height: 34px;
  }

  .brand-copy strong {
    font-size: 18px;
  }

  .brand-copy small {
    font-size: 11px;
  }

  .profile-button {
    min-height: 34px;
    padding: 0 10px 0 6px;
    font-size: 12px;
  }

  .profile-badge {
    width: 28px;
    height: 28px;
  }

  .page-shell {
    padding: 16px;
  }

  .filter-sidebar,
  .composer-card {
    border-radius: 18px;
    padding: 16px;
  }

  .welcome-copy h2 {
    display: block;
    font-size: 26px;
  }

  .feature-strip {
    gap: 18px;
    justify-content: flex-start;
  }

  .ask-area {
    grid-template-columns: 1fr;
  }

  .primary-button {
    width: 100%;
  }

  .composer-area {
    position: static;
  }

}