/* ===== 设计令牌 ===== */
:root {
  --color-bg: #faf7f1;
  --color-surface: #ffffff;
  --color-surface-alt: #f3efe7;
  --color-ink: #262a23;
  --color-muted: #6d7268;
  --color-border: #e2dccf;
  --color-primary: #3f6f52;
  --color-primary-strong: #315840;
  --color-primary-soft: #e9f1ea;
  --color-primary-line: #b9cfbf;
  --color-user-bubble: #edf0e6;
  --color-danger: #a03a30;
  --color-danger-soft: #f8ecea;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --reading-width: 720px;
  --sidebar-width: 248px;
  --shadow-drawer: 0 8px 32px rgba(38, 42, 35, 0.18);
}

/* ===== 基础 ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-base);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
p,
ul,
ol,
dl {
  margin: 0;
}

button,
input,
textarea {
  font: inherit;
  color: inherit;
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -48px;
  left: var(--space-4);
  z-index: 60;
  padding: var(--space-2) var(--space-4);
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: top 0.15s ease;
}

.skip-link:focus-visible {
  top: var(--space-3);
  color: #fff;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: var(--space-2) var(--space-4);
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-weight: 600;
  transition: background-color 0.15s ease, border-color 0.15s ease;
}

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover:not(:disabled) {
  background: var(--color-primary-strong);
}

.btn-ghost {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-ink);
}

.btn-ghost:hover:not(:disabled) {
  background: var(--color-surface-alt);
}

.btn-block {
  width: 100%;
}

.form-error {
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--color-danger);
  border-left-width: 4px;
  border-radius: var(--radius-sm);
  background: var(--color-danger-soft);
  color: var(--color-danger);
  font-size: 0.925rem;
}

/* ===== 启动加载态 ===== */
.boot-view {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-muted);
  font-size: 0.925rem;
}

/* ===== 登录态 ===== */
.login-view {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-5);
}

.login-card {
  width: 100%;
  max-width: 380px;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.login-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.login-purpose {
  color: var(--color-muted);
  font-size: 0.925rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.field label {
  font-weight: 600;
  font-size: 0.925rem;
}

.field input {
  min-height: 44px;
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
}

.field input:focus-visible {
  outline-offset: 0;
  border-color: var(--color-primary);
}

/* ===== 应用布局 ===== */
.app-view {
  display: flex;
  min-height: 100vh;
  min-height: 100dvh;
}

.sidebar {
  flex: 0 0 var(--sidebar-width);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-surface-alt);
  border-right: 1px solid var(--color-border);
  min-height: 100vh;
  min-height: 100dvh;
}

.sidebar-identity {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-status {
  font-size: 0.8125rem;
  color: var(--color-muted);
}

.sidebar-status:empty {
  display: none;
}

.history-nav {
  flex: 1;
  overflow-y: auto;
}

.history-list {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.history-item-btn {
  display: block;
  width: 100%;
  min-height: 44px;
  padding: var(--space-2) var(--space-3);
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  background: transparent;
  text-align: left;
  cursor: pointer;
  font-size: 0.925rem;
}

.history-item-btn:hover {
  background: var(--color-surface);
}

.history-item-btn[aria-current="true"] {
  background: var(--color-primary-soft);
  border-color: var(--color-primary-line);
  font-weight: 600;
}

.history-item-title {
  display: block;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.history-item-date {
  display: block;
  font-size: 0.75rem;
  color: var(--color-muted);
}

.drawer-backdrop {
  display: none;
}

.app-column {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  max-height: 100vh;
  max-height: 100dvh;
}

.app-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-5);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface);
}

.drawer-toggle {
  display: none;
}

.conversation-title {
  flex: 1;
  min-width: 0;
  font-size: 1.0625rem;
  font-weight: 700;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.main-content {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-5);
}

.main-content:focus {
  outline: none;
}

.conversation-status {
  max-width: var(--reading-width);
  margin: 0 auto var(--space-4);
  color: var(--color-muted);
  font-size: 0.925rem;
}

/* ===== 消息流 ===== */
.messages {
  max-width: var(--reading-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.empty-state {
  padding: var(--space-6) var(--space-5);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  color: var(--color-muted);
}

.empty-state p + p {
  margin-top: var(--space-2);
}

.message {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  max-width: 92%;
}

.message-user {
  align-self: flex-end;
  align-items: flex-end;
}

.message-assistant {
  align-self: flex-start;
  align-items: flex-start;
}

.message-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--color-muted);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.kind-badge {
  display: inline-block;
  padding: 1px var(--space-2);
  border: 1px solid var(--color-primary-line);
  border-radius: 999px;
  background: var(--color-primary-soft);
  color: var(--color-primary-strong);
  font-size: 0.6875rem;
  font-weight: 700;
}

.kind-badge.kind-no-evidence {
  border-color: var(--color-danger);
  background: var(--color-danger-soft);
  color: var(--color-danger);
}

.message-body {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-lg);
  overflow-wrap: break-word;
  word-break: break-word;
}

.message-user .message-body {
  background: var(--color-user-bubble);
  border: 1px solid var(--color-border);
  border-bottom-right-radius: var(--radius-sm);
}

.message-assistant .message-body {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-bottom-left-radius: var(--radius-sm);
}

.message-body p + p {
  margin-top: var(--space-2);
}

/* 回答分区：语料证据用左侧竖线段落形态 */
.answer-section {
  margin-top: var(--space-4);
}

.answer-section-title {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--color-primary-strong);
  margin-bottom: var(--space-2);
}

.section-evidence {
  padding-left: var(--space-3);
  border-left: 3px solid var(--color-primary-line);
}

/* AI 判断用整块底板盒形态，与语料证据结构区分 */
.section-judgment {
  padding: var(--space-3);
  border: 1px solid var(--color-primary-line);
  border-radius: var(--radius-md);
  background: var(--color-primary-soft);
}

.section-steps ol,
.section-steps ul {
  padding-left: var(--space-5);
}

.section-steps li + li {
  margin-top: var(--space-1);
}

.clarification-list {
  margin-top: var(--space-3);
  padding-left: var(--space-5);
}

.clarification-list li + li {
  margin-top: var(--space-2);
}

.no-evidence-note {
  margin-top: var(--space-2);
  padding: var(--space-3);
  border: 1px dashed var(--color-danger);
  border-radius: var(--radius-md);
  background: var(--color-danger-soft);
}

/* 案例引用 */
.citations {
  margin-top: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.citations-title {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--color-primary-strong);
}

.citation {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
}

.citation summary {
  min-height: 44px;
  display: flex;
  align-items: center;
  padding: var(--space-2) var(--space-3);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 600;
  list-style: none;
}

.citation summary::-webkit-details-marker {
  display: none;
}

.citation summary::before {
  content: "";
  flex: 0 0 auto;
  margin-right: var(--space-2);
  border: solid var(--color-muted);
  border-width: 0 2px 2px 0;
  padding: 3px;
  transform: rotate(-45deg);
  transition: transform 0.15s ease;
}

.citation[open] summary::before {
  transform: rotate(45deg);
}

.citation-body {
  padding: 0 var(--space-3) var(--space-3);
  font-size: 0.875rem;
}

.citation-summary-text {
  color: var(--color-ink);
}

.citation-meta {
  margin-top: var(--space-2);
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-1) var(--space-3);
}

.citation-meta dt {
  color: var(--color-muted);
  font-weight: 600;
  white-space: nowrap;
}

.citation-meta dd {
  margin: 0;
  overflow-wrap: break-word;
}

/* ===== 输入区 ===== */
.composer {
  padding: var(--space-3) var(--space-5) var(--space-4);
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
}

.composer-error {
  max-width: var(--reading-width);
  margin: 0 auto var(--space-2);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.composer-error .retry-btn {
  min-height: 36px;
  padding: var(--space-1) var(--space-3);
  font-size: 0.875rem;
}

.composer-row {
  max-width: var(--reading-width);
  margin: 0 auto;
  display: flex;
  gap: var(--space-3);
  align-items: flex-end;
}

.composer textarea {
  flex: 1;
  min-width: 0;
  min-height: 48px;
  max-height: 180px;
  padding: var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  resize: vertical;
}

.composer textarea:focus-visible {
  outline-offset: 0;
  border-color: var(--color-primary);
}

/* ===== 窄屏抽屉 ===== */
@media (max-width: 760px) {
  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 40;
    width: min(84vw, 300px);
    min-height: 0;
    transform: translateX(-100%);
    transition: transform 0.2s ease;
    box-shadow: none;
  }

  .sidebar.drawer-open {
    transform: translateX(0);
    box-shadow: var(--shadow-drawer);
  }

  .drawer-backdrop {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 30;
    background: rgba(38, 42, 35, 0.4);
  }

  .drawer-toggle {
    display: inline-flex;
    min-height: 40px;
    padding: var(--space-1) var(--space-3);
    font-size: 0.875rem;
  }

  .app-header {
    padding: var(--space-2) var(--space-4);
  }

  .main-content {
    padding: var(--space-4);
  }

  .composer {
    padding: var(--space-2) var(--space-4) var(--space-3);
  }

  .message {
    max-width: 100%;
  }
}

/* ===== 降低动态效果 ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition: none !important;
    animation: none !important;
  }
}