/*
职责与边界：
- 定义单页 Web Demo 的移动优先视觉样式，包括入口页、聊天工作区、老师调试按钮与底部抽屉；
- 仅覆盖本项目页面与 vendored quikchat 在本页面中的局部样式，不重写其完整布局系统。

关键副作用：
- 会覆盖 quikchat 默认主题中的部分颜色、边框、间距与输入区表现；
- 通过页面状态类驱动入口与聊天区的过渡动画。

关键依赖与约束：
- 依赖 `index.html` 中的结构类名与 `quikchat.css` 提供的基础 DOM；
- 保持 mobile-first，桌面仅做适度扩展，不引入多栏后台布局。
*/

:root {
  color-scheme: light;
  --paper-bg: #f4ede2;
  --paper-panel: rgba(255, 251, 244, 0.92);
  --paper-panel-strong: rgba(255, 248, 239, 0.98);
  --paper-line: rgba(69, 53, 34, 0.16);
  --paper-line-strong: rgba(69, 53, 34, 0.28);
  --ink-strong: #2a241b;
  --ink: #4a4136;
  --ink-soft: #7b6f60;
  --accent: #3f6a57;
  --accent-soft: rgba(63, 106, 87, 0.12);
  --accent-warm: #b36b3d;
  --student-surface: #f4e5b5;
  --teacher-surface: #fffdf9;
  --system-surface: #ece4d5;
  --sheet-shadow: 0 -18px 40px rgba(54, 40, 24, 0.16);
  --surface-shadow: 0 18px 42px rgba(73, 56, 34, 0.1);
  --radius-lg: 24px;
  --radius-md: 18px;
  --radius-sm: 12px;
  --shell-width: 760px;
  --transition-slow: 320ms cubic-bezier(0.2, 0.8, 0.2, 1);
  --transition-fast: 180ms ease;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  min-height: 100%;
  overflow: hidden;
}

body {
  margin: 0;
  min-height: 100dvh;
  color: var(--ink-strong);
  font-family: "Source Han Serif SC", "STSong", "Noto Serif SC", serif;
  background:
    radial-gradient(circle at top left, rgba(230, 174, 111, 0.18), transparent 24rem),
    radial-gradient(circle at bottom right, rgba(112, 153, 132, 0.14), transparent 22rem),
    linear-gradient(180deg, #f7f1e7 0%, var(--paper-bg) 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(rgba(130, 102, 70, 0.04), rgba(130, 102, 70, 0.04)),
    repeating-linear-gradient(
      0deg,
      transparent 0,
      transparent 13px,
      rgba(109, 87, 59, 0.03) 13px,
      rgba(109, 87, 59, 0.03) 14px
    );
  opacity: 0.75;
}

button,
textarea {
  font: inherit;
}

.demo-shell {
  position: relative;
  width: min(100%, var(--shell-width));
  height: 100dvh;
  min-height: 100dvh;
  margin: 0 auto;
  padding: 28px 18px 24px;
  overflow: hidden;
}

.entry-screen,
.chat-screen {
  height: 100%;
  min-height: 0;
  transition:
    opacity var(--transition-slow),
    transform var(--transition-slow);
}

body[data-screen="entry"] .entry-screen {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

body[data-screen="entry"] .chat-screen {
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  position: absolute;
  inset: 28px 18px 24px;
}

body[data-screen="chat"] .entry-screen {
  opacity: 0;
  transform: translateY(-22px);
  pointer-events: none;
  position: absolute;
  inset: 28px 18px auto;
}

body[data-screen="chat"] .chat-screen {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.entry-screen {
  display: grid;
  align-content: center;
  gap: 28px;
  overflow: auto;
}

.entry-copy {
  display: grid;
  gap: 12px;
  padding-bottom: 16px;
  border-bottom: 1px dashed var(--paper-line-strong);
}

.eyebrow {
  margin: 0;
  color: var(--accent);
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-family: "Avenir Next", "PingFang SC", sans-serif;
}

.entry-screen h1,
.chat-header h2,
.debug-sheet__header h2 {
  margin: 0;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.entry-screen h1 {
  max-width: 14ch;
  font-size: clamp(2.35rem, 10vw, 3.9rem);
  line-height: 1.02;
}

.entry-lead {
  margin: 0;
  max-width: 30rem;
  color: var(--ink);
  font-size: 1rem;
  line-height: 1.75;
}

.preset-list {
  display: grid;
  gap: 12px;
}

.preset-button {
  display: grid;
  gap: 6px;
  width: 100%;
  padding: 18px 18px 20px;
  border: 1px solid var(--paper-line);
  border-radius: var(--radius-md);
  background: linear-gradient(180deg, var(--paper-panel) 0%, rgba(255, 248, 239, 0.84) 100%);
  color: inherit;
  text-align: left;
  box-shadow: var(--surface-shadow);
  transition:
    transform var(--transition-fast),
    border-color var(--transition-fast),
    background var(--transition-fast);
}

.preset-button:active {
  transform: translateY(1px);
}

.preset-button:hover,
.preset-button:focus-visible {
  border-color: var(--accent);
  background: linear-gradient(180deg, rgba(255, 252, 247, 0.98) 0%, rgba(247, 238, 224, 0.94) 100%);
  outline: none;
}

.preset-button__index {
  color: var(--accent-warm);
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-family: "Avenir Next", "PingFang SC", sans-serif;
}

.preset-button__title {
  font-size: 1.35rem;
}

.preset-button__hint {
  color: var(--ink-soft);
  font-size: 0.95rem;
  line-height: 1.6;
}

.chat-screen {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  gap: 18px;
  overflow: hidden;
}

.chat-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  flex-shrink: 0;
  gap: 16px;
  padding-bottom: 14px;
  border-bottom: 1px dashed var(--paper-line-strong);
}

.chat-header__meta {
  display: grid;
  gap: 4px;
}

.chat-header h2 {
  font-size: clamp(1.85rem, 8vw, 2.5rem);
  line-height: 1.04;
}

.chat-status {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.95rem;
  line-height: 1.5;
}

.ghost-button {
  flex-shrink: 0;
  padding: 10px 14px;
  border: 1px solid var(--paper-line);
  border-radius: 999px;
  background: rgba(255, 250, 242, 0.72);
  color: var(--ink);
}

.chat-surface {
  display: flex;
  flex: 1;
  min-height: 0;
  border: 1px solid var(--paper-line);
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(255, 252, 247, 0.9) 0%, rgba(250, 243, 233, 0.94) 100%);
  box-shadow: var(--surface-shadow);
  overflow: hidden;
}

.chat-thread {
  display: flex;
  flex: 1;
  min-height: 0;
}

.chat-thread .quikchat-base {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
  color: var(--ink-strong);
  background: transparent;
}

.chat-thread .quikchat-messages-wrapper {
  display: flex;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

.chat-thread .quikchat-messages-area {
  flex: 1;
  min-height: 0;
  padding: 18px 16px 8px;
  overflow-y: auto;
  background:
    linear-gradient(180deg, rgba(255, 252, 247, 0.36) 0%, rgba(249, 242, 231, 0.4) 100%);
}

.chat-thread .quikchat-message {
  margin-bottom: 14px;
  padding: 0;
}

.chat-thread .quikchat-user-label {
  color: var(--ink-soft);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  font-family: "Avenir Next", "PingFang SC", sans-serif;
}

.chat-thread .quikchat-message-content {
  padding: 14px 14px 15px;
  border: 1px solid var(--paper-line);
  border-radius: 18px;
  background: var(--teacher-surface);
  line-height: 1.8;
  box-shadow: 0 8px 18px rgba(82, 60, 36, 0.06);
}

.chat-thread .quikchat-role-user .quikchat-message-content {
  margin-left: auto;
  max-width: min(94%, 32rem);
  border-color: rgba(179, 107, 61, 0.18);
  background: linear-gradient(180deg, rgba(247, 232, 181, 0.92) 0%, rgba(244, 229, 181, 0.98) 100%);
}

.chat-thread .quikchat-role-assistant .quikchat-message-content {
  max-width: min(92%, 34rem);
}

.chat-thread .quikchat-typing .quikchat-message-content {
  min-width: clamp(6.5rem, 30vw, 9rem);
}

.chat-thread .quikchat-role-system .quikchat-message-content {
  margin: 0 auto;
  max-width: min(90%, 28rem);
  border-style: dashed;
  background: var(--system-surface);
  color: var(--ink);
  font-size: 0.96rem;
}

.chat-thread .quikchat-input-area {
  flex-shrink: 0;
  padding: 12px;
  border-top: 1px dashed var(--paper-line-strong);
  background: rgba(255, 248, 239, 0.88);
}

.chat-thread .quikchat-input-textbox {
  min-height: 44px;
  max-height: 168px;
  padding: 11px 12px;
  border: 1px solid var(--paper-line);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.76);
  color: var(--ink-strong);
}

.chat-thread .quikchat-input-textbox::placeholder {
  color: var(--ink-soft);
}

.chat-thread .quikchat-input-send-btn {
  flex: 0 0 5.5rem;
  inline-size: 5.5rem;
  min-width: 88px;
  padding: 0 16px;
  border: 0;
  border-radius: 14px;
  background: var(--accent);
  color: #f5efe4;
  font-weight: 600;
}

.chat-thread .quikchat-input-textbox:focus,
.chat-thread .quikchat-input-send-btn:focus-visible,
.ghost-button:focus-visible,
.preset-button:focus-visible,
.message-debug-trigger:focus-visible {
  outline: 2px solid rgba(63, 106, 87, 0.42);
  outline-offset: 2px;
}

.chat-thread .quikchat-input-send-btn:disabled,
.ghost-button:disabled {
  opacity: 0.56;
}

.chat-thread .quikchat-scroll-bottom {
  background: rgba(255, 249, 241, 0.92);
  color: var(--ink);
}

.message-meta-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
}

.message-debug-trigger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border: 1px solid var(--paper-line-strong);
  border-radius: 999px;
  background: rgba(255, 250, 242, 0.86);
  color: var(--ink-soft);
  font-size: 0.8rem;
  line-height: 1;
}

.message-debug-trigger[data-ready="true"] {
  border-color: rgba(63, 106, 87, 0.34);
  color: var(--accent);
}

.debug-sheet {
  position: fixed;
  inset: 0;
  z-index: 30;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  pointer-events: none;
}

.debug-sheet__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(32, 25, 18, 0.36);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.debug-sheet__panel {
  position: relative;
  width: min(100%, 760px);
  max-height: min(72svh, 42rem);
  padding: 10px 18px 26px;
  border-radius: 26px 26px 0 0;
  background: var(--paper-panel-strong);
  box-shadow: var(--sheet-shadow);
  transform: translateY(102%);
  transition: transform var(--transition-slow);
  overflow: auto;
}

.debug-sheet.is-open {
  pointer-events: auto;
}

.debug-sheet.is-open .debug-sheet__backdrop {
  opacity: 1;
}

.debug-sheet.is-open .debug-sheet__panel {
  transform: translateY(0);
}

.debug-sheet__grabber {
  width: 52px;
  height: 5px;
  margin: 0 auto 14px;
  border-radius: 999px;
  background: rgba(90, 72, 49, 0.18);
}

.debug-sheet__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 14px;
  border-bottom: 1px dashed var(--paper-line-strong);
}

.debug-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin: 18px 0 0;
}

.debug-list dt {
  color: var(--ink-soft);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-family: "Avenir Next", "PingFang SC", sans-serif;
}

.debug-list dd {
  margin: 0 0 4px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(69, 53, 34, 0.08);
  color: var(--ink-strong);
  line-height: 1.75;
}

.debug-empty {
  padding: 18px 0 6px;
  color: var(--ink-soft);
  line-height: 1.7;
}

@media (min-width: 720px) {
  .demo-shell {
    padding: 34px 28px 30px;
  }

  body[data-screen="entry"] .chat-screen,
  body[data-screen="chat"] .entry-screen {
    inset: 34px 28px 30px;
  }

  .preset-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .chat-thread {
    min-height: 0;
  }

  .chat-thread .quikchat-messages-area {
    padding-inline: 22px;
  }

  .debug-sheet__panel {
    padding-inline: 24px;
  }
}