/* 基础：重置、通用控件、导航栏、输入框、登录与恢复、设置小窗、提示 */

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body {
  background: var(--env); color: var(--ink); font: var(--t-body);
  -webkit-font-smoothing: antialiased; -webkit-tap-highlight-color: transparent;
  text-rendering: optimizeLegibility; overflow: hidden; overscroll-behavior: none;
}
button, input, select, textarea { font: inherit; color: inherit; }
h1, h2, h3, h4, p { margin-top: 0; }
a { color: inherit; }
[hidden] { display: none !important; }
sub, sup { font-size: .68em; line-height: 0; position: relative; vertical-align: baseline; }
sup { top: -.52em; }
sub { bottom: -.22em; }
.sr-only, .sr { position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.icon-definitions { position: absolute; width: 0; height: 0; overflow: hidden; }
.icon { width: 22px; height: 22px; flex: none; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
.icon.sm { width: 18px; height: 18px; }
::placeholder { color: var(--muted); opacity: 1; }
::selection { background: var(--accent-tint); color: var(--ink); }
:focus { outline: none; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: var(--r-control); }

/* ---------- 按钮：默认是次要按钮；.primary 深色主操作 ---------- */
button {
  cursor: pointer; border: 0; margin: 0; touch-action: manipulation;
  min-height: 44px; padding: 0 16px; border-radius: var(--r-control);
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  background: var(--control); color: var(--ink); font: var(--t-control); white-space: nowrap;
  transition: background var(--d-state) var(--ease-out), color var(--d-state) var(--ease-out), transform var(--d-press) var(--ease-out), box-shadow var(--d-state);
}
button:active { transform: scale(.975); background: var(--control-press); }
button:disabled, button[aria-disabled="true"] { cursor: not-allowed; color: var(--muted); background: var(--control); transform: none; }
button.primary, .btn-primary { background: var(--ink); color: #fff; font-weight: 600; }
button.primary:active, .btn-primary:active { background: #33353b; }
button.primary:disabled { background: var(--control-press); color: var(--muted); font-weight: 400; }
button.quiet, .btn-text { background: transparent; color: var(--ink-2); padding: 0 12px; }
button.quiet:active, .btn-text:active { background: var(--control); }
button.text-button { background: transparent; min-height: 36px; padding: 0 8px; color: var(--ink-2); text-decoration: underline; text-underline-offset: 3px; }
.icon-btn { width: 44px; min-width: 44px; padding: 0; border-radius: 14px; background: transparent; color: var(--ink-2); }
.icon-btn:active { background: var(--control-press); }
@media (hover: hover) and (pointer: fine) {
  button:not(:disabled):hover { background: var(--control-hover); }
  button.primary:not(:disabled):hover, .btn-primary:not(:disabled):hover { background: #33353b; }
  button.quiet:not(:disabled):hover, .btn-text:not(:disabled):hover, .icon-btn:not(:disabled):hover { background: var(--control); }
}

input, select, textarea {
  min-width: 0; border: 0; border-radius: var(--r-control); padding: 11px 14px; background: var(--paper);
  box-shadow: inset 0 0 0 1px var(--line-strong); color: var(--ink); font: var(--t-body);
  transition: box-shadow var(--d-state) var(--ease-out);
}
input:focus, select:focus, textarea:focus { box-shadow: inset 0 0 0 1.5px var(--ink-2), 0 0 0 4px var(--accent-soft); }
input:disabled, select:disabled, textarea:disabled { background: var(--control); color: var(--muted); }
input[type="checkbox"], input[type="radio"] { box-shadow: none; width: 18px; height: 18px; accent-color: var(--accent); padding: 0; }
/* 全站滑块一个样：细轨、走过的部分用强调色、白色圆点。--fill 由 ui.mjs 的 paintRange 维护；网课只看页同样的形状，配色换成深底 */
input[type="range"] { -webkit-appearance: none; appearance: none; height: 32px; box-shadow: none; padding: 0; background: transparent; cursor: pointer; --fill: 0%; }
input[type="range"]::-webkit-slider-runnable-track { height: 4px; border-radius: 2px; background: linear-gradient(90deg, var(--accent) var(--fill), var(--line) var(--fill)); }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 16px; height: 16px; margin-top: -6px; border-radius: 50%; background: var(--paper); box-shadow: 0 1px 3px rgba(20, 22, 28, .3), 0 0 0 .5px rgba(20, 22, 28, .14); }
input[type="range"]:active::-webkit-slider-thumb { scale: 1.1; }
textarea { resize: vertical; line-height: 1.6; }
details > summary { cursor: pointer; }
.muted { color: var(--muted); }
.error { color: var(--danger); font: var(--t-control); }

/* ---------- 外壳 ---------- */
#workspace { position: fixed; inset: 0; }
.views { position: absolute; inset: 0; }
.view { position: absolute; inset: 0; overflow: hidden; }
/* 有导航栏的页面给它让出位置；导航栏本身不占版面，进出首页时页面不跳 */
#courses, #homeworkView { left: var(--rail); }

/* ---------- 导航栏：只有图标，长按显示名称；首页和课堂里不显示 ---------- */
.rail {
  position: absolute; z-index: 20; left: 0; top: 0; bottom: 0; width: var(--rail);
  display: flex; flex-direction: column; align-items: center; padding: 18px 0 16px; gap: 6px;
  transition: opacity var(--d-state) var(--ease-out), translate 260ms var(--ease-out), visibility 0s;
}
#workspace[data-page="home"] .rail, #workspace[data-page="classroom"] .rail, #workspace:not([data-page]) .rail {
  opacity: 0; translate: -14px 0; visibility: hidden; pointer-events: none;
  transition: opacity var(--d-fade) var(--ease-out), translate 200ms var(--ease-out), visibility 0s linear var(--d-state);
}
html[data-app-ask] .rail { display: none; }
[data-subject="math"] { --subject: var(--s-math); --subject-tint: var(--s-math-tint); }
[data-subject="physics"] { --subject: var(--s-physics); --subject-tint: var(--s-physics-tint); }
[data-subject="chemistry"] { --subject: var(--s-chemistry); --subject-tint: var(--s-chemistry-tint); }
[data-subject="biology"] { --subject: var(--s-biology); --subject-tint: var(--s-biology-tint); }
[data-subject="english"] { --subject: var(--s-english); --subject-tint: var(--s-english-tint); }
[data-subject="chinese"] { --subject: var(--s-chinese); --subject-tint: var(--s-chinese-tint); }
.rail-spacer { flex: 1; }
.rail-item {
  position: relative; width: 48px; height: 48px; min-height: 48px; padding: 0; border-radius: 15px;
  display: grid; place-items: center; color: var(--ink-2); background: transparent;
  user-select: none; -webkit-user-select: none; -webkit-touch-callout: none;
}
.rail-item:active { transform: scale(.975); background: var(--control-press); }
.rail-item[aria-current="page"] { background: var(--paper); color: var(--ink); box-shadow: var(--sh-touch); }
.rail-item[aria-current="page"]::before { content: ""; position: absolute; left: -10px; top: 15px; bottom: 15px; width: 3px; border-radius: 3px; background: var(--accent); }
.rail-item.is-light { width: 44px; height: 44px; min-height: 44px; color: var(--muted-on-env); }
.rail-item.is-light .icon { width: 19px; height: 19px; }
.rail-item[data-pending="true"] { color: var(--muted-on-env); }
.rail-brand { display: grid; place-items: center; flex: none; width: 44px; height: 44px; margin-bottom: 8px; }
.mark { width: 26px; height: 26px; background: url(icons/mark.svg) center / contain no-repeat; display: inline-block; flex: none; }
@media (hover: hover) and (pointer: fine) {
  .rail-item:not(:disabled):hover { background: var(--control-hover); }
  .rail-item[aria-current="page"]:hover { background: var(--paper); }
}
.rail-tip {
  position: absolute; left: calc(100% + 10px); top: 50%; translate: 0 -50%; white-space: nowrap; z-index: 30;
  padding: 6px 10px; border-radius: 10px; background: var(--ink); color: #fff; font: var(--t-caption);
  pointer-events: none; opacity: 0; scale: .96; transform-origin: left center;
  transition: opacity var(--d-fade) var(--ease-out), scale var(--d-fade) var(--ease-out);
}
.rail-item[data-tip="show"] .rail-tip { opacity: 1; scale: 1; }

@media (max-width: 560px) {
  #courses, #homeworkView { left: 0; bottom: calc(60px + env(safe-area-inset-bottom)); }
  #workspace[data-page="home"] .rail, #workspace[data-page="classroom"] .rail { translate: 0 14px; }
  .rail { top: auto; right: 0; width: 100%; height: calc(60px + env(safe-area-inset-bottom)); flex-direction: row; justify-content: space-around; padding: 6px 8px env(safe-area-inset-bottom); gap: 0; border-top: 1px solid var(--line); background: var(--env); }
  .rail-brand { display: none; }
  .rail-spacer { display: none; }
  .rail-item.is-light { width: 44px; height: 44px; }
  .rail-item[aria-current="page"]::before { left: 15px; right: 15px; top: auto; bottom: -6px; width: auto; height: 3px; }
  .rail-tip { left: 50%; top: auto; bottom: calc(100% + 8px); translate: -50% 0; transform-origin: center bottom; }
}

/* ---------- 老师形象：圆形占位（等正式 OC） ---------- */
.dots { --size: 28px; width: var(--size); height: var(--size); flex: none; position: relative; display: inline-block; }
.dots svg { width: 100%; height: 100%; display: block; overflow: visible; }
.dots .face { fill: var(--ink); }
.dots .eye { fill: #fff; transform-box: fill-box; transform-origin: center; transition: transform 260ms var(--ease-out); }
.dots .eyes { transition: transform 320ms var(--ease-out); }
.dots[data-mood="listen"] .eyes { transform: translate(1.2px, -.4px); }
.dots[data-mood="think"] .eye { transform: scaleY(.45); }
.dots[data-blink="true"] .eye { transform: scaleY(.1); transition-duration: 90ms; }

/* ---------- 输入框：空时禁用发送，有字时深色发送 ---------- */
.composer {
  position: relative; background: var(--paper); border-radius: 24px;
  box-shadow: var(--sh-paper), 0 0 0 1px rgba(20, 22, 28, .035);
  transition: box-shadow var(--d-state) var(--ease-out);
}
.composer:focus-within { box-shadow: var(--sh-paper), 0 0 0 1px var(--line-strong), 0 0 0 4px var(--accent-soft); }
.composer-row { display: flex; align-items: flex-end; gap: 8px; padding: 12px 12px 12px 14px; }
.composer-lead { display: grid; place-items: center; width: 44px; height: 44px; flex: none; }
.composer textarea {
  flex: 1; min-width: 0; border: 0; outline: 0; resize: none; background: transparent; box-shadow: none;
  font: var(--t-body); font-size: 17px; line-height: 24px; padding: 10px 4px; min-height: 44px; max-height: 144px; border-radius: 0;
}
.composer textarea:focus { box-shadow: none; }
.act { position: relative; width: 44px; min-width: 44px; height: 44px; min-height: 44px; padding: 0; flex: none; border-radius: 50%; display: grid; place-items: center; background: var(--ink); color: #fff; }
.act:disabled { background: var(--control); color: var(--faint); }
.act:active { transform: scale(.94); background: #33353b; }
@media (hover: hover) and (pointer: fine) { .act:not(:disabled):hover { background: #33353b; } }

/* ---------- 连续弧线：转圈（加载） ---------- */
.arc { width: 20px; height: 20px; flex: none; display: inline-block; }
.arc svg { width: 100%; height: 100%; display: block; overflow: visible; }
.arc .arc-track { fill: none; stroke: var(--accent-soft); stroke-width: 2.2; }
.arc .arc-line { fill: none; stroke: var(--accent); stroke-width: 2.2; stroke-linecap: round; stroke-dasharray: 18 70; transform-origin: 12px 12px; animation: arc-spin 850ms linear infinite; }
@keyframes arc-spin { to { transform: rotate(360deg); } }

/* ---------- 就近提示 ---------- */
.inline-error {
  display: flex; align-items: center; gap: 10px; padding: 8px 8px 8px 14px; border-radius: 14px;
  background: var(--danger-tint); color: var(--danger); font: var(--t-control);
}
.inline-error p { margin: 0; flex: 1; }
.inline-error button { background: #fff; color: var(--ink); box-shadow: var(--sh-touch); min-height: 36px; }

/* 页面切换中的轻提示（右上角浮层） */
#navigationStatus {
  position: fixed; z-index: 70; top: 14px; left: 50%; translate: -50% 0; max-width: min(560px, calc(100vw - 32px));
  margin: 0; padding: 10px 16px; border-radius: 14px; background: var(--float); box-shadow: var(--sh-float);
  font: var(--t-control); color: var(--ink-2);
}

/* ---------- 登录与恢复：一张安静的白色卡片 ---------- */
.login { position: fixed; inset: 0; display: grid; place-items: center; padding: 24px; overflow-y: auto; }
.login-card { width: min(400px, 100%); background: var(--paper); border-radius: var(--r-paper); box-shadow: var(--sh-paper); padding: 34px 32px 28px; }
.wordmark { display: inline-flex; align-items: center; gap: 10px; font: 600 19px/1 var(--font); letter-spacing: .02em; color: var(--ink); }
.wordmark .mark { width: 20px; height: 20px; }
.login-card h1 { font: var(--t-title); margin: 28px 0 4px; }
.login-card .lead { color: var(--muted); font: var(--t-control); margin: 0 0 22px; }
.field { display: block; margin-bottom: 12px; }
.field > span { display: block; font: var(--t-caption); color: var(--ink-2); margin: 0 0 6px 2px; }
.field input { width: 100%; height: 48px; }
.password-tools { display: flex; align-items: center; gap: 8px; min-height: 36px; margin: -4px 0 4px; }
.password-tools button { min-height: 36px; padding: 0 10px; background: transparent; color: var(--ink-2); font: var(--t-caption); }
.password-tools span { color: var(--danger); font: var(--t-caption); }
.login-card button.primary { width: 100%; height: 48px; margin-top: 8px; }
.login-card .error:empty { display: none; }
.login-card .error { margin: 14px 0 0; padding: 10px 12px; border-radius: 12px; background: var(--danger-tint); }
.keep { display: flex; align-items: center; justify-content: center; gap: 6px; color: var(--muted); font: var(--t-caption); margin: 16px 0 0; }
.keep .icon { width: 14px; height: 14px; }

/* 连接提示：一句话浮在下方，页面不动；页面藏起来时才居中 */
#connectionRecovery {
  position: fixed; z-index: 80; left: 50%; bottom: calc(24px + env(safe-area-inset-bottom)); translate: -50% 0; display: flex; align-items: center; gap: 8px;
  max-width: min(520px, calc(100vw - 32px)); min-height: 44px; padding: 6px 18px; border-radius: 22px; background: var(--paper); box-shadow: var(--sh-float);
  animation: note-in var(--d-state) var(--ease-out);
}
#connectionRecovery[hidden] { display: none; }
html:has(#workspace[hidden]) #connectionRecovery { bottom: 50%; translate: -50% 50%; }
#connectionRecovery p { margin: 0; font: var(--t-caption); color: var(--ink-2); }
#connectionRecovery button { flex: none; min-height: 32px; margin-right: -8px; color: var(--accent-ink); font-weight: 600; }
@keyframes note-in { from { opacity: 0; } }

/* ---------- 设置小窗（账号、退出、减少动态效果） ---------- */
.settings-pop {
  position: fixed; z-index: 60; width: 300px; padding: 16px; border-radius: var(--r-float);
  background: var(--float); box-shadow: var(--sh-float);
}
.settings-pop h2 { font: var(--t-heading); margin: 0 0 12px; }
.settings-row { display: flex; align-items: center; gap: 12px; min-height: 48px; font: var(--t-control); color: var(--ink-2); }
.settings-row + .settings-row { border-top: 1px solid var(--line); }
.settings-row .grow { flex: 1; }
.settings-row b { color: var(--ink); font-weight: 600; }
.settings-pop { width: 340px; max-width: calc(100vw - 24px); overflow-y: auto; overscroll-behavior: contain; }
.model-section { border-top: 1px solid var(--line); padding: 10px 0 8px; }
.model-title { font: var(--t-control); color: var(--ink-2); padding-bottom: 4px; }
.model-list { display: grid; }
.model-row {
  display: grid; grid-template-columns: 20px minmax(0, 1fr) auto; align-items: center; gap: 10px;
  min-height: 44px; padding: 0 8px; margin: 0 -8px; border-radius: 10px; background: transparent;
  color: var(--ink); font: var(--t-control); text-align: left;
}
.model-row:disabled { opacity: 1; cursor: default; }
.model-row:disabled:not([aria-checked="true"]) .model-name { color: var(--muted); }
@media (hover: hover) and (pointer: fine) { .model-row:not(:disabled):hover { background: var(--accent-tint); transform: none; } }
.model-row:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 0; }
.model-mark { width: 16px; height: 16px; border-radius: 50%; border: 1.5px solid var(--line-strong); justify-self: center; transition: border-color var(--d-state) var(--ease-out), box-shadow var(--d-state) var(--ease-out); }
.model-row[aria-checked="true"] .model-mark { border-color: var(--accent); box-shadow: inset 0 0 0 3.5px var(--float), inset 0 0 0 8px var(--accent); }
.model-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.model-id { font: var(--t-caption); color: var(--muted); white-space: nowrap; }
.model-row[data-busy="true"] .model-id { color: var(--accent-ink); }
.model-foot { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 10px; min-height: 40px; padding-top: 4px; }
.model-test { min-height: 36px; padding: 0 10px; margin-left: -10px; font: var(--t-control); color: var(--accent-ink); background: transparent; }
.model-note { font: var(--t-caption); color: var(--muted); }
.model-note[data-tone="ok"] { color: var(--accent-ink); }
.model-note[data-tone="bad"] { color: var(--danger); }
.model-note[data-tone="busy"]::after { content: "…"; }
.switch { position: relative; width: 52px; min-width: 52px; height: 44px; min-height: 44px; padding: 0; border-radius: 13px; background: transparent; }
.switch::before { content: ""; position: absolute; left: 4px; top: 9px; width: 44px; height: 26px; border-radius: 13px; background: var(--line-strong); transition: background var(--d-state) var(--ease-out); }
.switch::after { content: ""; position: absolute; left: 7px; top: 12px; width: 20px; height: 20px; border-radius: 50%; background: #fff; box-shadow: var(--sh-touch); transition: translate var(--d-state) var(--ease-out); }
.switch[aria-checked="true"]::before { background: var(--accent); }
.switch[aria-checked="true"]::after { translate: 18px 0; }
.switch:active, .switch:not(:disabled):hover { transform: none; background: transparent; }
@media (hover: hover) and (pointer: fine) { .switch:not(:disabled):hover::before { background: var(--faint); } .switch[aria-checked="true"]:not(:disabled):hover::before { background: var(--accent-ink); } }

/* ---------- 减少动态效果（应用开关与系统设置都算） ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: 0ms !important; animation-duration: 0ms !important; }
}
:root[data-motion="reduced"] *, :root[data-motion="reduced"] *::before, :root[data-motion="reduced"] *::after { transition-duration: 0ms !important; animation-duration: 0ms !important; }
#navigationStatus button { min-height: 44px; margin-left: 10px; padding: 0 14px; }