/* ============ tokens ============ */
:root {
  --bg: #f3f4f6;
  --surface: #ffffff;
  --surface-2: #f6f7f9;
  --surface-3: #eceef2;
  --text: #16181d;
  --text-2: #565c69;
  --text-3: #8a909c;
  --border: rgba(16, 24, 40, 0.09);
  --border-strong: rgba(16, 24, 40, 0.17);
  --accent: #3355e6;
  --accent-2: #2a47c4;
  --accent-soft: rgba(51, 85, 230, 0.1);
  --accent-ink: #ffffff;
  --danger: #d4383b;
  --danger-soft: rgba(212, 56, 59, 0.1);
  --success: #1f9d62;
  --shadow-1: 0 1px 2px rgba(16, 24, 40, 0.05), 0 1px 3px rgba(16, 24, 40, 0.07);
  --shadow-2: 0 8px 24px rgba(16, 24, 40, 0.12), 0 2px 6px rgba(16, 24, 40, 0.08);
  --shadow-3: 0 18px 48px rgba(16, 24, 40, 0.2), 0 4px 12px rgba(16, 24, 40, 0.08);
  --viewer-bg: #e5e7eb;
  --page-shadow: 0 1px 2px rgba(0, 0, 0, 0.1), 0 4px 14px rgba(0, 0, 0, 0.06);
  --topbar-bg: rgba(255, 255, 255, 0.86);
  --read-bg: #ffffff;
  --figure-bg: transparent;
  --scrim: rgba(10, 12, 16, 0.36);
  --overlay-dark: rgba(22, 24, 30, 0.88);
  --radius-s: 8px;
  --radius: 12px;
  --radius-l: 18px;
  --font-ui: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC",
    "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Iowan Old Style", Charter, "Source Serif 4", "Source Serif Pro", Georgia, "Noto Serif CJK SC",
    "Songti SC", "STSong", serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --font-read: var(--font-serif);
  --read-size: 17px;
  --topbar-h: 52px;
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --kb: 0px;
  --panel-w: 420px;
  --sheet-h: 58dvh;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e1014;
    --surface: #171a20;
    --surface-2: #1d2027;
    --surface-3: #272b34;
    --text: #e8eaef;
    --text-2: #a5abb8;
    --text-3: #747b89;
    --border: rgba(255, 255, 255, 0.08);
    --border-strong: rgba(255, 255, 255, 0.15);
    --accent: #7d95ff;
    --accent-2: #9aacff;
    --accent-soft: rgba(125, 149, 255, 0.15);
    --accent-ink: #0d1020;
    --danger: #ff6b6e;
    --danger-soft: rgba(255, 107, 110, 0.12);
    --success: #4cc98e;
    --shadow-1: 0 1px 2px rgba(0, 0, 0, 0.4);
    --shadow-2: 0 8px 24px rgba(0, 0, 0, 0.45);
    --shadow-3: 0 18px 48px rgba(0, 0, 0, 0.6);
    --viewer-bg: #0a0b0e;
    --page-shadow: 0 1px 3px rgba(0, 0, 0, 0.6);
    --topbar-bg: rgba(23, 26, 32, 0.86);
    --read-bg: #15171c;
    --figure-bg: #f4f4f2;
    --scrim: rgba(0, 0, 0, 0.55);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0e1014;
  --surface: #171a20;
  --surface-2: #1d2027;
  --surface-3: #272b34;
  --text: #e8eaef;
  --text-2: #a5abb8;
  --text-3: #747b89;
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.15);
  --accent: #7d95ff;
  --accent-2: #9aacff;
  --accent-soft: rgba(125, 149, 255, 0.15);
  --accent-ink: #0d1020;
  --danger: #ff6b6e;
  --danger-soft: rgba(255, 107, 110, 0.12);
  --success: #4cc98e;
  --shadow-1: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-2: 0 8px 24px rgba(0, 0, 0, 0.45);
  --shadow-3: 0 18px 48px rgba(0, 0, 0, 0.6);
  --viewer-bg: #0a0b0e;
  --page-shadow: 0 1px 3px rgba(0, 0, 0, 0.6);
  --topbar-bg: rgba(23, 26, 32, 0.86);
  --read-bg: #15171c;
  --figure-bg: #f4f4f2;
  --scrim: rgba(0, 0, 0, 0.55);
  color-scheme: dark;
}

/* ============ base ============ */
*,
*::before,
*::after {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  height: 100%;
}
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  overscroll-behavior-y: none;
}
button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
  -webkit-user-select: none;
  user-select: none;
}
button:disabled {
  cursor: default;
}
input,
textarea,
select {
  font: inherit;
  color: inherit;
}
a {
  color: var(--accent);
}
svg.icon {
  width: var(--icon, 20px);
  height: var(--icon, 20px);
  flex: none;
  display: block;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}
[hidden] {
  display: none !important;
}

/* ============ controls ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 44px;
  padding: 0 18px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 15px;
  transition: background-color 0.15s, transform 0.1s, opacity 0.15s;
  white-space: nowrap;
}
.btn:active:not(:disabled) {
  transform: scale(0.98);
}
.btn:disabled {
  opacity: 0.55;
}
.btn-primary {
  background: var(--accent);
  color: var(--accent-ink);
}
.btn-primary:hover:not(:disabled) {
  background: var(--accent-2);
}
.btn-secondary {
  background: var(--surface-3);
  color: var(--text);
}
.btn-ghost {
  color: var(--text-2);
}
.btn-ghost:hover:not(:disabled) {
  background: var(--surface-3);
}
.btn-danger {
  background: var(--danger);
  color: #fff;
}
.btn-sm {
  height: 34px;
  padding: 0 12px;
  font-size: 13.5px;
  border-radius: 9px;
}
.icon-btn {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  display: inline-grid;
  place-items: center;
  color: var(--text-2);
  flex: none;
  transition: background-color 0.15s;
}
.icon-btn:hover {
  background: var(--surface-3);
}
.icon-btn:active {
  background: var(--surface-3);
}
.icon-btn.on {
  color: var(--accent);
  background: var(--accent-soft);
}
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 30px;
  padding: 0 12px;
  border-radius: 999px;
  background: var(--surface-3);
  color: var(--text-2);
  font-size: 13px;
  font-weight: 550;
}
.chip:active {
  background: var(--border-strong);
}
.chip svg {
  --icon: 15px;
  color: var(--accent);
}
.input {
  width: 100%;
  height: 44px;
  border-radius: 11px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--text);
  padding: 0 12px;
  font-size: 16px;
  outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}
textarea.input {
  height: auto;
  min-height: 96px;
  padding: 10px 12px;
  line-height: 1.5;
  resize: vertical;
}
.input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
select.input {
  appearance: none;
  -webkit-appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, var(--text-3) 50%),
    linear-gradient(135deg, var(--text-3) 50%, transparent 50%);
  background-position: calc(100% - 18px) 19px, calc(100% - 13px) 19px;
  background-size: 5px 5px;
  background-repeat: no-repeat;
  padding-right: 34px;
}
.seg {
  display: inline-flex;
  background: var(--surface-3);
  border-radius: 10px;
  padding: 2px;
  flex: none;
}
.seg button {
  height: 30px;
  padding: 0 11px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
}
.seg button.on {
  background: var(--surface);
  color: var(--text);
  box-shadow: var(--shadow-1);
}
.spinner {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid currentColor;
  border-right-color: transparent;
  animation: spin 0.7s linear infinite;
  flex: none;
}
@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}
@keyframes up {
  from {
    transform: translateY(12px);
    opacity: 0;
  }
}
@keyframes pop {
  from {
    transform: scale(0.94);
    opacity: 0;
  }
}
@keyframes fade {
  from {
    opacity: 0;
  }
}

/* ============ toast & dialogs ============ */
.toast-wrap {
  position: fixed;
  left: 50%;
  transform: translateX(-50%);
  bottom: calc(96px + var(--safe-bottom));
  z-index: 200;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  pointer-events: none;
  width: max-content;
  max-width: 92vw;
}
.toast {
  background: var(--overlay-dark);
  color: #fff;
  padding: 10px 16px;
  border-radius: 12px;
  font-size: 14px;
  line-height: 1.45;
  box-shadow: var(--shadow-2);
  animation: up 0.2s ease-out;
  pointer-events: auto;
  max-width: min(92vw, 460px);
}
.toast.error {
  background: #b8292c;
}
.toast.leaving {
  opacity: 0;
  transition: opacity 0.25s;
}
.scrim {
  position: fixed;
  inset: 0;
  background: var(--scrim);
  z-index: 70;
  animation: fade 0.2s;
}
.modal {
  position: fixed;
  z-index: 80;
  left: 0;
  right: 0;
  bottom: 0;
  max-height: calc(100dvh - var(--safe-top) - 24px);
  background: var(--surface);
  border-radius: var(--radius-l) var(--radius-l) 0 0;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-3);
  animation: up 0.24s ease-out;
}
.modal-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 8px 10px 18px;
  border-bottom: 1px solid var(--border);
  font-weight: 650;
  font-size: 16px;
}
.modal-head .title {
  flex: 1;
}
.modal-body {
  overflow-y: auto;
  padding: 6px 18px 18px;
  overscroll-behavior: contain;
}
.modal-foot {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
  padding: 12px 18px calc(12px + var(--safe-bottom));
  border-top: 1px solid var(--border);
}
.dialog {
  position: fixed;
  z-index: 90;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: min(360px, calc(100vw - 40px));
  background: var(--surface);
  border-radius: var(--radius-l);
  box-shadow: var(--shadow-3);
  padding: 20px 20px 16px;
  animation: pop 0.16s ease-out;
}
.dialog h3 {
  margin: 0 0 8px;
  font-size: 17px;
}
.dialog p {
  margin: 0 0 18px;
  color: var(--text-2);
  font-size: 14.5px;
}
.dialog .actions {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
}
@media (min-width: 720px) {
  .modal {
    left: 50%;
    top: 50%;
    bottom: auto;
    width: 580px;
    max-height: min(86vh, 860px);
    transform: translate(-50%, -50%);
    border-radius: var(--radius-l);
    animation: fade 0.18s ease-out;
  }
  .modal-foot {
    padding-bottom: 12px;
  }
}

/* ============ menu & drawer & peek ============ */
.menu {
  position: fixed;
  z-index: 75;
  min-width: 220px;
  max-width: calc(100vw - 16px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow-3);
  padding: 6px;
  animation: pop 0.14s ease-out;
  transform-origin: top right;
}
.menu-item {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 10px 12px;
  border-radius: 9px;
  font-size: 14.5px;
  text-align: left;
  color: var(--text);
}
.menu-item svg {
  color: var(--text-2);
  --icon: 19px;
}
.menu-item:hover,
.menu-item:active {
  background: var(--surface-3);
}
.menu-item.danger,
.menu-item.danger svg {
  color: var(--danger);
}
.menu-item .right {
  margin-left: auto;
  color: var(--text-3);
  font-size: 13px;
}
.menu-sep {
  height: 1px;
  background: var(--border);
  margin: 5px 8px;
}
.menu-row {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 8px 6px 12px;
  font-size: 14.5px;
}
.menu-row .label {
  flex: 1;
  display: flex;
  gap: 12px;
  align-items: center;
}
.menu-row .label svg {
  color: var(--text-2);
  --icon: 19px;
}
.drawer {
  position: fixed;
  z-index: 72;
  top: 0;
  bottom: 0;
  left: 0;
  width: min(86vw, 380px);
  background: var(--surface);
  display: flex;
  flex-direction: column;
  padding-top: var(--safe-top);
  box-shadow: var(--shadow-3);
  animation: drawer-in 0.24s cubic-bezier(0.2, 0.8, 0.2, 1);
}
@keyframes drawer-in {
  from {
    transform: translateX(-100%);
  }
}
.drawer-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 8px 8px 18px;
  min-height: 56px;
  border-bottom: 1px solid var(--border);
  font-weight: 650;
}
.drawer-head .title {
  flex: 1;
}
.drawer-body {
  flex: 1;
  overflow-y: auto;
  padding: 6px 0 calc(16px + var(--safe-bottom));
  overscroll-behavior: contain;
}
.toc-item {
  display: block;
  width: 100%;
  text-align: left;
  padding: 10px 18px;
  font-size: 14.5px;
  line-height: 1.45;
  color: var(--text);
}
.toc-item:active,
.toc-item:hover {
  background: var(--surface-2);
}
.toc-item.l2 {
  padding-left: 34px;
  font-size: 13.5px;
  color: var(--text-2);
}
.toc-item.l3 {
  padding-left: 48px;
  font-size: 13px;
  color: var(--text-3);
}
.toc-item .pg {
  float: right;
  color: var(--text-3);
  font-size: 12px;
  margin-left: 8px;
}
.toc-empty {
  padding: 18px;
  color: var(--text-3);
  font-size: 14px;
}
.page-jump {
  display: flex;
  gap: 8px;
  padding: 12px 18px;
  border-bottom: 1px solid var(--border);
  align-items: center;
  font-size: 14px;
  color: var(--text-2);
}
.page-jump .input {
  width: 90px;
  height: 36px;
}
.peek {
  position: fixed;
  z-index: 65;
  left: 10px;
  right: 10px;
  bottom: calc(12px + var(--safe-bottom));
  max-height: 48dvh;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow-3);
  display: flex;
  flex-direction: column;
  animation: up 0.2s ease-out;
}
.peek-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 6px 0 16px;
  font-size: 12.5px;
  color: var(--text-3);
  font-weight: 600;
}
.peek-head .title {
  flex: 1;
}
.peek-body {
  overflow-y: auto;
  padding: 2px 16px 12px;
  font-size: 14.5px;
  line-height: 1.6;
  overscroll-behavior: contain;
}
.peek-actions {
  display: flex;
  gap: 8px;
  padding: 8px 12px 12px;
  justify-content: flex-end;
  flex-wrap: wrap;
}
@media (min-width: 720px) {
  .peek {
    left: 50%;
    right: auto;
    width: 540px;
    transform: translateX(-50%);
    animation: fade 0.16s;
  }
}
.back-chip {
  position: fixed;
  z-index: 34;
  left: 50%;
  transform: translateX(-50%);
  bottom: calc(84px + var(--safe-bottom));
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--overlay-dark);
  color: #fff;
  border-radius: 999px;
  padding: 9px 16px;
  font-size: 13.5px;
  font-weight: 600;
  box-shadow: var(--shadow-2);
  animation: up 0.2s ease-out;
}
.back-chip svg {
  --icon: 16px;
}

/* ============ login ============ */
.login {
  min-height: 100dvh;
  display: grid;
  place-items: center;
  padding: 24px 18px;
}
.login-card {
  width: min(380px, 100%);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  box-shadow: var(--shadow-2);
  padding: 28px 22px 22px;
}
.login-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}
.lang-switch {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
  padding: 6px 10px;
  border-radius: 8px;
  background: var(--surface-3);
}
.login-card h1 {
  font-size: 20px;
  margin: 0 0 4px;
}
.login-card p {
  margin: 0 0 18px;
  color: var(--text-2);
  font-size: 14px;
}
.login-card .btn {
  width: 100%;
  margin-top: 12px;
}
.form-error {
  color: var(--danger);
  font-size: 13.5px;
  margin-top: 8px;
  min-height: 1em;
}

/* ============ home ============ */
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.01em;
}
.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: var(--accent);
  color: var(--accent-ink);
  display: grid;
  place-items: center;
}
.brand-mark svg {
  --icon: 19px;
}
.home {
  max-width: 680px;
  margin: 0 auto;
  padding: calc(var(--safe-top) + 10px) 16px calc(var(--safe-bottom) + 40px);
}
.home-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
}
.hero {
  margin-top: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 22px 18px 18px;
  box-shadow: var(--shadow-1);
}
.hero h1 {
  font-size: 22px;
  line-height: 1.3;
  margin: 0 0 6px;
  letter-spacing: 0.01em;
}
.hero .sub {
  color: var(--text-2);
  margin: 0 0 18px;
  font-size: 14px;
}
.import-form {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.input-wrap {
  position: relative;
}
.input-wrap svg {
  position: absolute;
  left: 13px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-3);
  --icon: 18px;
  pointer-events: none;
}
.input-wrap .input {
  padding-left: 40px;
  height: 48px;
  background: var(--surface-2);
}
.import-form .btn {
  height: 48px;
}
@media (min-width: 560px) {
  .import-form {
    flex-direction: row;
  }
  .import-form .input-wrap {
    flex: 1;
  }
}
.or-divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 16px 0;
  color: var(--text-3);
  font-size: 12.5px;
}
.or-divider::before,
.or-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}
.upload-btn {
  position: relative;
  overflow: hidden;
  width: 100%;
  min-height: 54px;
  border: 1.5px dashed var(--border-strong);
  background: var(--surface-2);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-weight: 600;
  font-size: 15px;
  transition: border-color 0.15s, background-color 0.15s;
}
.upload-btn svg {
  color: var(--accent);
}
.upload-btn .progress {
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  background: var(--accent-soft);
  width: 0;
  transition: width 0.15s;
}
.upload-btn > span {
  position: relative;
  display: flex;
  gap: 10px;
  align-items: center;
}
.upload-btn .sub {
  font-weight: 450;
  color: var(--text-3);
  font-size: 12.5px;
}
.home.dragging .upload-btn {
  border-color: var(--accent);
  background: var(--accent-soft);
}
.examples {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin-top: 14px;
  font-size: 12.5px;
  color: var(--text-3);
}
.examples .chip {
  height: 26px;
  font-size: 12px;
  font-weight: 500;
  padding: 0 10px;
}
.import-error {
  color: var(--danger);
  font-size: 13.5px;
  margin-top: 10px;
  line-height: 1.5;
}
.section-title {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin: 28px 4px 10px;
  font-size: 13px;
  font-weight: 650;
  color: var(--text-2);
}
.section-title .count {
  font-weight: 500;
  color: var(--text-3);
}
.paper-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.paper-card {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: start;
  gap: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 13px 6px 12px 15px;
  cursor: pointer;
  transition: background-color 0.15s, transform 0.1s;
}
.paper-card:active {
  transform: scale(0.992);
  background: var(--surface-2);
}
.paper-card .t {
  font-weight: 620;
  font-size: 15.5px;
  line-height: 1.38;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.paper-card .m {
  margin-top: 5px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 8px;
  font-size: 12.5px;
  color: var(--text-3);
}
.paper-card .authors {
  color: var(--text-2);
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.src-tag {
  display: inline-flex;
  align-items: center;
  height: 20px;
  padding: 0 7px;
  border-radius: 6px;
  background: var(--surface-3);
  color: var(--text-2);
  font-size: 11.5px;
  font-weight: 600;
}
.src-tag.arxiv {
  background: rgba(179, 27, 27, 0.1);
  color: #b31b1b;
}
:root[data-theme="dark"] .src-tag.arxiv {
  color: #ff8c8c;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .src-tag.arxiv {
    color: #ff8c8c;
  }
}
.paper-card .more {
  margin-top: -6px;
}
.empty {
  text-align: center;
  color: var(--text-3);
  font-size: 14px;
  padding: 36px 16px;
  border: 1.5px dashed var(--border);
  border-radius: 16px;
}
.skeleton {
  height: 72px;
  border-radius: 14px;
  background: linear-gradient(90deg, var(--surface) 0%, var(--surface-2) 50%, var(--surface) 100%);
  background-size: 200% 100%;
  animation: shimmer 1.2s infinite;
}
@keyframes shimmer {
  to {
    background-position: -200% 0;
  }
}

/* ============ reader shell ============ */
.reader {
  position: fixed;
  inset: 0;
  background: var(--viewer-bg);
  overflow: hidden;
}
.reader-stage {
  position: absolute;
  inset: 0;
  overflow: hidden;
  transition: right 0.25s ease;
}
.view-host {
  position: absolute;
  inset: 0;
}
.topbar {
  position: absolute;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  height: calc(var(--topbar-h) + var(--safe-top));
  padding: var(--safe-top) 6px 0;
  display: flex;
  align-items: center;
  gap: 2px;
  background: var(--topbar-bg);
  -webkit-backdrop-filter: saturate(1.6) blur(16px);
  backdrop-filter: saturate(1.6) blur(16px);
  border-bottom: 1px solid var(--border);
  transition: transform 0.25s ease;
}
.reader.chrome-hidden .topbar {
  transform: translateY(-100%);
}
.topbar .title {
  flex: 1;
  min-width: 0;
  padding: 0 6px;
  font-weight: 620;
  font-size: 15px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.topbar .seg {
  margin: 0 4px;
}
.reader-loading {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  z-index: 5;
  color: var(--text-2);
  font-size: 14px;
  pointer-events: none;
}
.reader-loading .box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}
.bar {
  width: 180px;
  height: 4px;
  border-radius: 2px;
  background: var(--border);
  overflow: hidden;
}
.bar > div {
  height: 100%;
  width: 0;
  background: var(--accent);
  transition: width 0.2s;
}
.reader-error {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 24px;
  text-align: center;
  color: var(--text-2);
}
.page-pill {
  position: absolute;
  z-index: 15;
  left: 12px;
  bottom: calc(18px + var(--safe-bottom));
  background: var(--overlay-dark);
  color: #fff;
  font-size: 12.5px;
  font-weight: 600;
  padding: 5px 11px;
  border-radius: 999px;
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
  font-variant-numeric: tabular-nums;
}
.page-pill.show {
  opacity: 1;
}
.fab {
  position: absolute;
  z-index: 25;
  right: 16px;
  bottom: calc(16px + var(--safe-bottom));
  width: 54px;
  height: 54px;
  border-radius: 50%;
  background: var(--accent);
  color: var(--accent-ink);
  display: grid;
  place-items: center;
  box-shadow: var(--shadow-2);
  transition: transform 0.25s ease, opacity 0.25s;
}
.fab svg {
  --icon: 24px;
}
.fab .badge {
  position: absolute;
  top: -2px;
  right: -2px;
  min-width: 19px;
  height: 19px;
  padding: 0 5px;
  border-radius: 999px;
  background: var(--surface);
  color: var(--accent);
  font-size: 11px;
  font-weight: 700;
  display: grid;
  place-items: center;
  box-shadow: var(--shadow-1);
}
.reader.chrome-hidden .fab,
.reader.panel-open .fab,
.reader.selecting .fab {
  transform: translateY(90px);
  opacity: 0;
  pointer-events: none;
}
.tip {
  position: absolute;
  z-index: 26;
  left: 50%;
  bottom: calc(86px + var(--safe-bottom));
  transform: translateX(-50%);
  width: max-content;
  max-width: min(88vw, 420px);
  background: var(--overlay-dark);
  color: #fff;
  font-size: 13.5px;
  line-height: 1.5;
  padding: 10px 14px;
  border-radius: 12px;
  box-shadow: var(--shadow-2);
  animation: up 0.25s ease-out;
}

/* ============ PDF view ============ */
.pdf-scroll {
  position: absolute;
  inset: 0;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  touch-action: pan-x pan-y;
  outline: none;
}
.pdf-scroll .pdfViewer {
  padding: calc(var(--topbar-h) + var(--safe-top) + 10px) 0 calc(130px + var(--safe-bottom));
}
.pdf-scroll .pdfViewer.removePageBorders .page {
  margin: 0 auto 12px;
  box-shadow: var(--page-shadow);
}
.reader.pdf-invert .pdfViewer .page {
  background: #1b1c1f;
}
.reader.pdf-invert .pdfViewer .page canvas {
  filter: invert(0.9) hue-rotate(180deg);
}
.pdf-scroll .textLayer ::selection {
  background: rgba(51, 85, 230, 0.3);
}
.capture-layer {
  position: absolute;
  inset: 0;
  z-index: 18;
  cursor: crosshair;
  touch-action: none;
  background: rgba(0, 0, 0, 0.06);
}
.capture-rect {
  position: absolute;
  border: 2px solid var(--accent);
  border-radius: 4px;
  background: rgba(51, 85, 230, 0.08);
  box-shadow: 0 0 0 9999px rgba(0, 0, 0, 0.3);
  pointer-events: none;
}
.capture-hint {
  position: absolute;
  z-index: 19;
  left: 50%;
  top: calc(var(--safe-top) + var(--topbar-h) + 14px);
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 12px;
  width: max-content;
  max-width: 92vw;
  background: var(--overlay-dark);
  color: #fff;
  font-size: 13.5px;
  padding: 6px 6px 6px 16px;
  border-radius: 999px;
  box-shadow: var(--shadow-2);
}
.capture-hint button {
  background: rgba(255, 255, 255, 0.16);
  color: #fff;
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 600;
}

/* ============ HTML view (arXiv LaTeXML) ============ */
.html-scroll {
  position: absolute;
  inset: 0;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  background: var(--read-bg);
}
.html-article {
  max-width: 760px;
  margin: 0 auto;
  padding: calc(var(--topbar-h) + var(--safe-top) + 22px) 20px calc(150px + var(--safe-bottom));
  font-family: var(--font-read);
  font-size: var(--read-size);
  line-height: 1.68;
  color: var(--text);
  overflow-wrap: break-word;
}
.html-article.sans {
  --font-read: var(--font-ui);
}
.html-article ::selection {
  background: rgba(51, 85, 230, 0.25);
}
.html-article .ltx_document > .ltx_title_document,
.html-article h1.ltx_title {
  font-family: var(--font-ui);
  font-size: 1.42em;
  line-height: 1.3;
  margin: 0 0 0.6em;
  font-weight: 700;
  letter-spacing: 0;
  hyphens: manual;
}
.html-article h2.ltx_title {
  font-family: var(--font-ui);
  font-size: 1.16em;
  line-height: 1.35;
  margin: 1.8em 0 0.6em;
  font-weight: 700;
  hyphens: manual;
}
.html-article h3.ltx_title,
.html-article h4.ltx_title,
.html-article h5.ltx_title {
  font-family: var(--font-ui);
  font-size: 1.02em;
  line-height: 1.4;
  margin: 1.5em 0 0.5em;
  font-weight: 650;
  hyphens: manual;
}
.html-article h6.ltx_title {
  font-family: var(--font-ui);
  font-size: 0.85em;
  margin: 0 0 0.4em;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-2);
}
.html-article .ltx_tag {
  margin-right: 0.45em;
}
.html-article .ltx_authors {
  font-family: var(--font-ui);
  font-size: 0.8em;
  line-height: 1.55;
  color: var(--text-2);
  margin-bottom: 1.6em;
}
.html-article .ltx_authors .ltx_creator {
  display: inline-block;
  vertical-align: top;
  margin: 0 1.2em 0.5em 0;
}
.html-article .ltx_authors .ltx_author_before,
.html-article .ltx_contact_name,
.html-article .ltx_role_email {
  display: none;
}
.html-article .ltx_personname {
  font-weight: 600;
  color: var(--text);
}
.html-article .ltx_personname .pr-affil {
  display: block;
  font-weight: 400;
  color: var(--text-3);
  font-size: 0.92em;
}
.html-article .ltx_author_notes {
  display: block;
  font-size: 0.92em;
  color: var(--text-3);
  margin-top: 0.2em;
}
.html-article .ltx_author_notes .ltx_contact {
  display: block;
}
.html-article .ltx_author_notes .ltx_font_bold {
  font-weight: inherit;
}
.html-article .ltx_abstract {
  background: var(--surface-2);
  border-radius: 12px;
  padding: 1em 1.1em;
  margin: 0 0 1.8em;
  font-size: 0.94em;
}
.html-article .ltx_p {
  margin: 0 0 0.85em;
}
.html-article .ltx_para {
  margin: 0;
}
.html-article .ltx_figure,
.html-article .ltx_table {
  margin: 1.4em 0;
  text-align: center;
  overflow-x: auto;
  overflow-y: hidden;
}
.html-article .ltx_figure img,
.html-article .ltx_graphics {
  max-width: 100%;
  height: auto;
  background: var(--figure-bg);
  border-radius: 4px;
  cursor: zoom-in;
}
.html-article .ltx_figure svg {
  max-width: 100%;
  height: auto;
  background: var(--figure-bg);
}
.html-article .ltx_flex_figure {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: flex-end;
  gap: 8px;
}
.html-article .ltx_flex_cell {
  flex: 1 1 200px;
  min-width: 0;
}
.html-article .ltx_flex_break {
  flex-basis: 100%;
  height: 0;
}
.html-article .ltx_caption {
  display: block;
  font-family: var(--font-ui);
  font-size: 0.82em;
  line-height: 1.55;
  color: var(--text-2);
  text-align: left;
  margin-top: 0.6em;
}
.html-article .ltx_tabular {
  border-collapse: collapse;
  margin: 0 auto;
  font-family: var(--font-ui);
  font-size: 0.8em;
  line-height: 1.35;
}
.html-article .ltx_td,
.html-article .ltx_th {
  padding: 0.25em 0.55em;
  vertical-align: middle;
}
.html-article .ltx_border_t {
  border-top: 1px solid var(--border-strong);
}
.html-article .ltx_border_tt {
  border-top: 2px solid var(--text-3);
}
.html-article .ltx_border_b {
  border-bottom: 1px solid var(--border-strong);
}
.html-article .ltx_border_bb {
  border-bottom: 2px solid var(--text-3);
}
.html-article .ltx_border_r {
  border-right: 1px solid var(--border-strong);
}
.html-article .ltx_border_l {
  border-left: 1px solid var(--border-strong);
}
.html-article .ltx_align_left {
  text-align: left;
}
.html-article .ltx_align_right {
  text-align: right;
}
.html-article .ltx_align_center,
.html-article .ltx_centering {
  text-align: center;
}
.html-article .ltx_equation,
.html-article .ltx_equationgroup,
.html-article .ltx_eqn_table {
  display: block;
  width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  margin: 0.8em 0;
}
.html-article .ltx_equation tbody,
.html-article .ltx_equationgroup tbody,
.html-article .ltx_eqn_table tbody {
  display: table;
  width: 100%;
}
.html-article .ltx_eqn_cell {
  padding: 0;
}
.html-article .ltx_eqn_center_padleft,
.html-article .ltx_eqn_center_padright {
  width: 50%;
}
.html-article .ltx_eqn_eqno {
  text-align: right;
  white-space: nowrap;
  font-size: 0.9em;
  color: var(--text-2);
  padding-left: 0.8em;
}
.html-article math {
  font-size: 1.04em;
}
.html-article math[display="block"] {
  overflow-x: auto;
  overflow-y: hidden;
  max-width: 100%;
}
.html-article .ltx_font_bold {
  font-weight: 650;
}
.html-article .ltx_font_italic,
.html-article .ltx_emph {
  font-style: italic;
}
.html-article .ltx_font_typewriter {
  font-family: var(--font-mono);
  font-size: 0.9em;
}
.html-article .ltx_font_smallcaps {
  font-variant: small-caps;
}
.html-article .ltx_listing {
  font-family: var(--font-mono);
  font-size: 0.82em;
  line-height: 1.5;
  background: var(--surface-2);
  border-radius: 8px;
  padding: 0.8em;
  overflow-x: auto;
  white-space: pre;
  text-align: left;
}
.html-article .ltx_itemize,
.html-article .ltx_enumerate {
  padding-left: 1.3em;
  margin: 0 0 0.85em;
}
.html-article .ltx_item {
  margin: 0.25em 0;
}
.html-article .ltx_item > .ltx_tag {
  margin-left: -1.1em;
  margin-right: 0.3em;
}
.html-article .ltx_theorem,
.html-article .ltx_proof {
  margin: 1em 0;
}
.html-article .ltx_theorem .ltx_title {
  display: inline;
  margin: 0 0.4em 0 0;
  font-size: 1em;
}
.html-article .ltx_note_outer {
  display: none;
}
.html-article .ltx_note_mark {
  color: var(--accent);
  cursor: pointer;
  font-weight: 650;
  padding: 0 1px;
}
.html-article .ltx_ERROR,
.html-article .ltx_TOC,
.html-article .ltx_page_footer,
.html-article .ltx_pagination {
  display: none;
}
.html-article a.ltx_ref {
  color: var(--accent);
  text-decoration: none;
}
.html-article .ltx_cite a {
  color: var(--accent);
}
.html-article .ltx_bibliography {
  font-size: 0.86em;
  line-height: 1.55;
}
.html-article .ltx_biblist {
  list-style: none;
  padding: 0;
}
.html-article .ltx_bibitem {
  margin: 0 0 0.75em;
  padding-left: 0;
}
.html-article .ltx_bibitem .ltx_tag {
  font-weight: 600;
  color: var(--text-2);
}
.html-article .ltx_bibblock {
  display: inline;
}
.html-article .ltx_bibblock + .ltx_bibblock::before {
  content: " ";
}
.html-article .flash {
  animation: flash 1.6s ease-out;
}
@keyframes flash {
  0%,
  30% {
    background: var(--accent-soft);
  }
}

/* ============ selection bar ============ */
.selbar {
  position: fixed;
  z-index: 40;
  left: 50%;
  bottom: calc(16px + var(--safe-bottom) + var(--sel-offset, 0px));
  transform: translate(-50%, 14px);
  opacity: 0;
  pointer-events: none;
  display: flex;
  gap: 2px;
  padding: 5px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: var(--shadow-3);
  transition: opacity 0.16s, transform 0.16s;
}
.selbar.show {
  opacity: 1;
  transform: translate(-50%, 0);
  pointer-events: auto;
}
.selbar button {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  min-width: 64px;
  padding: 8px 10px 6px;
  border-radius: 13px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text);
}
.selbar button svg {
  color: var(--accent);
  --icon: 21px;
}
.selbar button:active,
.selbar button:hover {
  background: var(--surface-3);
}
.selbar.floating {
  bottom: auto;
  transform: none;
  border-radius: 12px;
  padding: 4px;
}
.selbar.floating.show {
  transform: none;
}
.selbar.floating button {
  flex-direction: row;
  gap: 6px;
  min-width: 0;
  padding: 7px 11px;
  border-radius: 9px;
  font-size: 13px;
}
.selbar.floating button svg {
  --icon: 17px;
}

/* ============ AI panel ============ */
.ai-panel {
  position: fixed;
  z-index: 30;
  left: 0;
  right: 0;
  bottom: 0;
  height: var(--sheet-h);
  max-height: calc(100vh - var(--safe-top) - 10px - var(--kb));
  max-height: calc(100dvh - var(--safe-top) - 10px - var(--kb));
  background: var(--surface);
  border-radius: 20px 20px 0 0;
  box-shadow: var(--shadow-3);
  display: flex;
  flex-direction: column;
  transform: translateY(110%);
  visibility: hidden;
  transition: transform 0.3s cubic-bezier(0.2, 0.8, 0.2, 1), height 0.22s ease, visibility 0s 0.3s;
}
.ai-panel.open {
  transform: translateY(calc(-1 * var(--kb)));
  visibility: visible;
  transition: transform 0.3s cubic-bezier(0.2, 0.8, 0.2, 1), height 0.22s ease, visibility 0s;
}
.ai-panel.dragging {
  transition: none;
}
.sheet-handle {
  flex: none;
  height: 20px;
  display: grid;
  place-items: center;
  touch-action: none;
  cursor: grab;
}
.sheet-handle::before {
  content: "";
  width: 40px;
  height: 5px;
  border-radius: 3px;
  background: var(--border-strong);
}
.ai-head {
  flex: none;
  display: flex;
  align-items: center;
  gap: 2px;
  padding: 0 6px 6px 16px;
  border-bottom: 1px solid var(--border);
  touch-action: none;
}
.ai-head .title {
  flex: 1;
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 650;
  font-size: 15.5px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.ai-head .title svg {
  color: var(--accent);
  --icon: 19px;
}
.ai-head .title .model {
  font-weight: 500;
  font-size: 12px;
  color: var(--text-3);
  overflow: hidden;
  text-overflow: ellipsis;
}
.ai-body {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  padding: 14px 16px 10px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.ai-foot {
  flex: none;
  border-top: 1px solid var(--border);
  padding: 8px 10px calc(8px + var(--safe-bottom));
  background: var(--surface);
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.ai-panel.kb-open .ai-foot {
  padding-bottom: 8px;
}
.quick-row {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: none;
}
.quick-row::-webkit-scrollbar {
  display: none;
}
.composer {
  display: flex;
  align-items: flex-end;
  gap: 8px;
}
.composer textarea {
  flex: 1;
  min-width: 0;
  resize: none;
  height: 42px;
  max-height: 140px;
  border-radius: 21px;
  border: 1px solid var(--border-strong);
  background: var(--surface-2);
  padding: 10px 15px;
  font-size: 16px;
  line-height: 1.35;
  outline: none;
  color: var(--text);
}
.composer textarea:focus {
  border-color: var(--accent);
}
.send-btn {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--accent);
  color: var(--accent-ink);
  display: grid;
  place-items: center;
  flex: none;
  transition: opacity 0.15s, transform 0.1s;
}
.send-btn:disabled {
  opacity: 0.35;
}
.send-btn:active:not(:disabled) {
  transform: scale(0.94);
}
.send-btn.stop {
  background: var(--text);
  color: var(--surface);
}
.quote {
  border-left: 3px solid var(--accent);
  background: var(--surface-2);
  border-radius: 4px 10px 10px 4px;
  padding: 9px 12px 8px;
  font-size: 14px;
  line-height: 1.55;
  color: var(--text-2);
}
.quote-text {
  display: -webkit-box;
  -webkit-line-clamp: 4;
  -webkit-box-orient: vertical;
  overflow: hidden;
  white-space: pre-wrap;
  font-family: var(--font-serif);
  overflow-wrap: anywhere;
}
.quote.expanded .quote-text {
  -webkit-line-clamp: unset;
  display: block;
}
.quote img {
  display: block;
  max-width: 100%;
  max-height: 220px;
  border-radius: 6px;
  background: #fff;
  margin: 2px 0 4px;
}
.quote-meta {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-top: 6px;
  font-size: 12px;
  color: var(--text-3);
}
.quote-meta button {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--accent);
  font-weight: 600;
}
.quote-meta svg {
  --icon: 14px;
}
.msg-user {
  align-self: flex-end;
  max-width: 86%;
  background: var(--accent-soft);
  padding: 8px 13px;
  border-radius: 16px 16px 4px 16px;
  font-size: 14.5px;
  line-height: 1.5;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}
.msg-action {
  align-self: center;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-3);
  font-weight: 600;
}
.msg-action::before,
.msg-action::after {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--border-strong);
}
.msg-ai {
  min-width: 0;
}
.msg-tools {
  display: flex;
  gap: 2px;
  margin-top: 4px;
  margin-left: -8px;
}
.msg-tools button {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  height: 30px;
  padding: 0 9px;
  border-radius: 8px;
  font-size: 12.5px;
  color: var(--text-3);
}
.msg-tools button:hover,
.msg-tools button:active {
  background: var(--surface-3);
  color: var(--text-2);
}
.msg-tools svg {
  --icon: 15px;
}
.msg-note {
  font-size: 12px;
  color: var(--text-3);
  margin-top: 4px;
}
.msg-error {
  background: var(--danger-soft);
  color: var(--danger);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 13.5px;
  line-height: 1.5;
}
.msg-error .btn {
  margin-top: 8px;
}
.thinking {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text-3);
  font-size: 13px;
  padding: 2px 0;
}
.dots {
  display: inline-flex;
  gap: 4px;
}
.dots i {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0.35;
  animation: dot 1.1s infinite ease-in-out;
}
.dots i:nth-child(2) {
  animation-delay: 0.15s;
}
.dots i:nth-child(3) {
  animation-delay: 0.3s;
}
@keyframes dot {
  40% {
    opacity: 1;
    transform: translateY(-2px);
  }
}
.notice {
  font-size: 12.5px;
  color: var(--text-3);
  background: var(--surface-2);
  padding: 6px 10px;
  border-radius: 8px;
}
.hist-new {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.hist-list {
  display: flex;
  flex-direction: column;
}
.hist-item {
  display: grid;
  grid-template-columns: 34px 1fr auto;
  gap: 10px;
  align-items: start;
  padding: 11px 0;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
}
.hist-item:last-child {
  border-bottom: 0;
}
.hist-kind {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  font-size: 14px;
  font-weight: 700;
  background: var(--accent-soft);
  color: var(--accent);
}
.hist-kind svg {
  --icon: 18px;
}
.hist-main {
  min-width: 0;
}
.hist-q {
  font-size: 14px;
  line-height: 1.45;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.hist-a {
  font-size: 12.5px;
  color: var(--text-3);
  margin-top: 3px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.hist-empty {
  color: var(--text-3);
  font-size: 14px;
  text-align: center;
  padding: 26px 8px;
}
.ai-intro {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.6;
}
.ai-intro ul {
  padding-left: 1.2em;
  margin: 6px 0 0;
}

/* desktop: the panel docks on the right */
@media (min-width: 900px) {
  .ai-panel {
    left: auto;
    top: 0;
    width: var(--panel-w);
    height: auto;
    max-height: none;
    border-radius: 0;
    border-left: 1px solid var(--border);
    box-shadow: none;
    transform: translateX(105%);
  }
  .ai-panel.open {
    transform: none;
  }
  .sheet-handle {
    display: none;
  }
  .ai-head {
    padding-top: calc(var(--safe-top) + 8px);
    min-height: calc(var(--topbar-h) + var(--safe-top));
  }
  .reader.panel-open .reader-stage {
    right: var(--panel-w);
  }
}

/* ============ markdown ============ */
.md {
  font-size: 15px;
  line-height: 1.72;
  overflow-wrap: anywhere;
}
.md > :first-child {
  margin-top: 0;
}
.md > :last-child {
  margin-bottom: 0;
}
.md p {
  margin: 0 0 0.7em;
}
.md ul,
.md ol {
  margin: 0 0 0.7em;
  padding-left: 1.4em;
}
.md li {
  margin: 0.2em 0;
}
.md li > p {
  margin: 0;
}
.md h1,
.md h2,
.md h3,
.md h4,
.md h5 {
  font-size: 1.02em;
  line-height: 1.45;
  margin: 1em 0 0.45em;
  font-weight: 680;
}
.md code {
  font-family: var(--font-mono);
  font-size: 0.87em;
  background: var(--surface-3);
  padding: 0.12em 0.36em;
  border-radius: 5px;
}
.md pre {
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 10px 12px;
  border-radius: 10px;
  overflow-x: auto;
  margin: 0 0 0.8em;
  line-height: 1.5;
}
.md pre code {
  background: none;
  padding: 0;
  font-size: 0.85em;
}
.md blockquote {
  margin: 0 0 0.7em;
  padding-left: 12px;
  border-left: 3px solid var(--border-strong);
  color: var(--text-2);
}
.md table {
  border-collapse: collapse;
  display: block;
  overflow-x: auto;
  margin: 0 0 0.8em;
  font-size: 0.92em;
}
.md th,
.md td {
  border: 1px solid var(--border-strong);
  padding: 5px 9px;
}
.md th {
  background: var(--surface-2);
}
.md hr {
  border: 0;
  height: 1px;
  background: var(--border);
  margin: 1em 0;
}
.md strong {
  font-weight: 680;
}
.md .katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  margin: 0.6em 0;
  padding: 2px 0;
}
.md .katex {
  font-size: 1.05em;
}
.md.streaming > :last-child::after {
  content: "";
  display: inline-block;
  width: 7px;
  height: 1.05em;
  margin-left: 2px;
  vertical-align: -0.15em;
  background: var(--accent);
  border-radius: 1px;
  animation: blink 1s steps(2) infinite;
}
@keyframes blink {
  50% {
    opacity: 0;
  }
}

/* ============ settings ============ */
.settings-group {
  margin-top: 20px;
}
.settings-group > h3 {
  margin: 0 0 2px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--text-3);
  font-weight: 700;
}
.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin: 14px 0 0;
}
.field > label,
.field > .label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
}
.field-row {
  display: flex;
  gap: 8px;
  align-items: center;
}
.field-row .input {
  flex: 1;
  min-width: 0;
}
.hint {
  font-size: 12.5px;
  color: var(--text-3);
  line-height: 1.55;
}
.hint.ok {
  color: var(--success);
}
.hint.err {
  color: var(--danger);
}
.switch-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: 14px;
  font-size: 14.5px;
}
.switch-row .hint {
  margin-top: 2px;
}
.switch {
  position: relative;
  width: 46px;
  height: 28px;
  flex: none;
}
.switch input {
  position: absolute;
  inset: 0;
  opacity: 0;
  margin: 0;
  cursor: pointer;
}
.switch span {
  position: absolute;
  inset: 0;
  border-radius: 999px;
  background: var(--border-strong);
  transition: background-color 0.18s;
  pointer-events: none;
}
.switch span::after {
  content: "";
  position: absolute;
  top: 3px;
  left: 3px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.25);
  transition: transform 0.18s;
}
.switch input:checked + span {
  background: var(--accent);
}
.switch input:checked + span::after {
  transform: translateX(18px);
}
details.advanced {
  margin-top: 20px;
  border-top: 1px solid var(--border);
  padding-top: 10px;
}
details.advanced > summary {
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-2);
  padding: 6px 0;
  list-style: none;
}
details.advanced > summary::-webkit-details-marker {
  display: none;
}
details.advanced > summary::before {
  content: "▸";
  display: inline-block;
  width: 1.1em;
  transition: transform 0.15s;
}
details.advanced[open] > summary::before {
  transform: rotate(90deg);
}
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

/* ============ lightbox ============ */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 85;
  background: rgba(0, 0, 0, 0.94);
  display: flex;
  flex-direction: column;
  animation: fade 0.18s;
}
.lightbox-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: calc(var(--safe-top) + 6px) 8px 6px 14px;
  color: #fff;
}
.lightbox-bar .title {
  flex: 1;
  font-size: 13px;
  opacity: 0.8;
}
.lightbox-bar .icon-btn {
  color: #fff;
}
.lightbox-bar .icon-btn:hover {
  background: rgba(255, 255, 255, 0.12);
}
.lightbox-img {
  flex: 1;
  overflow: auto;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  touch-action: pan-x pan-y;
}
.lightbox-img img {
  max-width: 100%;
  max-height: 100%;
  background: #fff;
  border-radius: 4px;
}
.lightbox-img.zoomed {
  align-items: flex-start;
  justify-content: flex-start;
}
.lightbox-img.zoomed img {
  max-width: none;
  max-height: none;
  width: 200%;
}
.lightbox-cap {
  color: rgba(255, 255, 255, 0.85);
  font-size: 13px;
  line-height: 1.5;
  padding: 8px 16px calc(12px + var(--safe-bottom));
  max-height: 30vh;
  overflow: auto;
}
.lightbox-actions {
  display: flex;
  gap: 8px;
  padding: 0 14px 10px;
}
.lightbox-actions .btn {
  height: 38px;
  font-size: 14px;
}