/* ═══════════════════════════════════════════════
   毕过AI — 全局样式
   左侧固定导航（PC）· 底部固定导航（手机）
═══════════════════════════════════════════════ */

/* ── 变量 ── */
:root {
  --p1: #4f46e5;
  --p2: #7c3aed;
  --p-light: rgba(79,70,229,0.08);
  --p-border: rgba(79,70,229,0.2);
  --grad-main: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  --grad-text: linear-gradient(135deg, #4f46e5, #7c3aed);
  --grad-btn: linear-gradient(135deg, #4f46e5 0%, #6d28d9 100%);
  --t-dark: #0f172a;
  --t-main: #1e293b;
  --t-sub: #475569;
  --t-muted: #94a3b8;
  --bg: #ffffff;
  --bg2: #f8fafc;
  --bg3: #f1f5f9;
  --border: #e2e8f0;
  --border-l: #c7d2fe;
  --sidebar-w: 220px;
  --bottom-nav-h: 64px;
  --r: 8px;
  --r-lg: 12px;
  --r-xl: 16px;
  --r-2xl: 20px;
  --r-full: 9999px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.1), 0 4px 12px rgba(0,0,0,0.05);
  --shadow-p: 0 8px 24px rgba(79,70,229,0.18);
}

/* ── 重置 ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Segoe UI', sans-serif;
  background: var(--bg2);
  color: var(--t-main);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  /* PC：左侧留出侧边栏宽度 */
  padding-left: var(--sidebar-w);
}
a { text-decoration: none; color: inherit; }
button { cursor: pointer; font-family: inherit; }
input, textarea, select { font-family: inherit; }

/* ══════════════════════════════
   左侧固定导航栏（PC）
══════════════════════════════ */
.sidebar {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: var(--sidebar-w);
  background: white;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  z-index: 200;
  box-shadow: 2px 0 12px rgba(0,0,0,0.04);
}

/* Logo 区 */
.sidebar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 24px 20px 20px;
  border-bottom: 1px solid var(--border);
}
.sidebar-logo-icon {
  width: 38px; height: 38px;
  background: var(--grad-main);
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 900; color: white;
  box-shadow: 0 4px 12px rgba(79,70,229,0.35);
  flex-shrink: 0;
}
.sidebar-logo-name {
  font-size: 17px; font-weight: 900; color: var(--t-dark); letter-spacing: -0.3px;
}
.sidebar-logo-badge {
  font-size: 9px; font-weight: 800;
  padding: 2px 6px;
  background: var(--grad-main); color: white;
  border-radius: var(--r-full); letter-spacing: 0.5px;
  margin-top: 2px;
}

/* 导航菜单 */
.sidebar-nav {
  flex: 1;
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  overflow-y: auto;
}
.sidebar-section-label {
  font-size: 10px; font-weight: 800; color: var(--t-muted);
  letter-spacing: 1px; text-transform: uppercase;
  padding: 8px 8px 4px;
  margin-top: 8px;
}
.sidebar-section-label:first-child { margin-top: 0; }
.sidebar-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: var(--r-lg);
  font-size: 14px; font-weight: 500; color: var(--t-sub);
  transition: all 0.2s;
  cursor: pointer;
}
.sidebar-link:hover { background: var(--bg2); color: var(--t-main); }
.sidebar-link.active {
  background: var(--p-light);
  color: var(--p1);
  font-weight: 700;
}
.sidebar-link-icon {
  width: 32px; height: 32px;
  border-radius: var(--r);
  display: flex; align-items: center; justify-content: center;
  font-size: 16px;
  background: var(--bg2);
  flex-shrink: 0;
  transition: background 0.2s;
}
.sidebar-link.active .sidebar-link-icon { background: rgba(79,70,229,0.12); }

/* 底部 CTA */
.sidebar-bottom {
  padding: 16px 12px;
  border-top: 1px solid var(--border);
}
.sidebar-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 100%;
  padding: 11px;
  background: var(--grad-btn);
  color: white;
  border-radius: var(--r-lg);
  font-size: 13px; font-weight: 700;
  box-shadow: 0 4px 14px rgba(79,70,229,0.3);
  transition: all 0.2s;
  border: none;
  cursor: pointer;
  text-decoration: none;
}
.sidebar-cta:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(79,70,229,0.4); }

/* ══════════════════════════════
   主内容区
══════════════════════════════ */
.main-content {
  min-height: 100vh;
  background: var(--bg2);
}

/* ══════════════════════════════
   页面顶部标题区
══════════════════════════════ */
.page-hero {
  padding: 48px 40px 40px;
  background: linear-gradient(180deg, #fafbff 0%, #f0f4ff 60%, #f8fafc 100%);
  border-bottom: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}
.page-hero-orb {
  position: absolute;
  width: 400px; height: 250px;
  background: radial-gradient(ellipse, rgba(79,70,229,0.08) 0%, transparent 70%);
  top: -50px; right: 0;
  pointer-events: none;
}
.page-hero h1 {
  font-size: 36px; font-weight: 900; color: var(--t-dark);
  letter-spacing: -1px; margin-bottom: 10px;
}
.page-hero-desc {
  font-size: 15px; color: var(--t-sub); line-height: 1.75;
}
.grad {
  background: var(--grad-text);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

/* ══════════════════════════════
   通用布局容器
══════════════════════════════ */
.page-body { padding: 28px 40px; }
.container { max-width: 1100px; margin: 0 auto; }

/* ══════════════════════════════
   通用按钮
══════════════════════════════ */
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 8px 16px; border: none; border-radius: var(--r-full);
  font-size: 13px; font-weight: 600; cursor: pointer;
  transition: all 0.2s; white-space: nowrap;
}
.btn:disabled { opacity: 0.6; cursor: not-allowed; transform: none !important; }
.btn-lg { padding: 13px 26px; font-size: 15px; }
.btn-sm { padding: 6px 14px; font-size: 12px; }
.btn-grad {
  background: var(--grad-btn); color: white;
  box-shadow: 0 4px 14px rgba(79,70,229,0.3);
}
.btn-grad:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(79,70,229,0.4); }
.btn-glass {
  background: white; border: 1px solid var(--border); color: var(--t-sub);
}
.btn-glass:hover { background: var(--bg2); color: var(--t-main); }
.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; background: var(--grad-btn); color: white;
  border-radius: var(--r-full); font-size: 14px; font-weight: 700;
  box-shadow: 0 6px 20px rgba(79,70,229,0.3); transition: all 0.2s;
  border: none; cursor: pointer;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 28px rgba(79,70,229,0.4); }
.btn-secondary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; background: white; color: var(--t-main);
  border-radius: var(--r-full); font-size: 14px; font-weight: 700;
  border: 1.5px solid var(--border); box-shadow: var(--shadow-sm);
  transition: all 0.2s; cursor: pointer;
}
.btn-secondary:hover { border-color: var(--p1); color: var(--p1); transform: translateY(-1px); }

/* ══════════════════════════════
   Panel 卡片
══════════════════════════════ */
.panel {
  background: white; border: 1px solid var(--border);
  border-radius: var(--r-xl); box-shadow: var(--shadow-sm); overflow: hidden;
}
.panel-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 20px; border-bottom: 1px solid var(--border); background: white;
}
.panel-head-left { display: flex; align-items: center; gap: 10px; }
.panel-head-icon {
  width: 34px; height: 34px; background: var(--p-light);
  border-radius: var(--r); display: flex; align-items: center; justify-content: center; font-size: 17px;
}
.panel-head-title { font-size: 14px; font-weight: 700; color: var(--t-dark); }
.panel-head-sub { font-size: 12px; color: var(--t-muted); margin-top: 1px; }
.panel-body { padding: 20px; }

/* ══════════════════════════════
   表单元素
══════════════════════════════ */
.form-item { display: flex; flex-direction: column; gap: 5px; }
.form-label { font-size: 12px; font-weight: 700; color: var(--t-sub); letter-spacing: 0.2px; }
.req { color: #ef4444; }
.form-input, .form-select, .form-textarea {
  width: 100%; padding: 9px 12px;
  border: 1.5px solid var(--border); border-radius: var(--r);
  font-size: 14px; color: var(--t-main); background: white;
  transition: border-color 0.2s, box-shadow 0.2s; outline: none;
}
.form-input:focus, .form-select:focus, .form-textarea:focus {
  border-color: var(--p1); box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
}
.form-textarea { resize: vertical; line-height: 1.7; }

/* 提示框 */
.tip-box {
  display: flex; gap: 8px; padding: 10px 14px;
  background: rgba(79,70,229,0.05); border: 1px solid rgba(79,70,229,0.15);
  border-radius: var(--r); font-size: 12px; color: var(--p1); line-height: 1.6;
}

/* ══════════════════════════════
   Section 标题
══════════════════════════════ */
.sec-head { text-align: center; margin-bottom: 40px; }
.sec-tag {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 12px; background: rgba(79,70,229,0.07);
  border: 1px solid rgba(79,70,229,0.2); border-radius: var(--r-full);
  font-size: 10px; font-weight: 800; color: var(--p1);
  letter-spacing: 0.8px; text-transform: uppercase; margin-bottom: 12px;
}
.sec-title {
  font-size: 30px; font-weight: 900; color: var(--t-dark);
  letter-spacing: -0.8px; line-height: 1.2; margin-bottom: 10px;
}
.sec-desc { font-size: 14px; color: var(--t-sub); max-width: 520px; margin: 0 auto; line-height: 1.75; }

/* ══════════════════════════════
   使用步骤
══════════════════════════════ */
.steps-wrap {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; position: relative;
}
.steps-wrap.steps-3 { grid-template-columns: repeat(3, 1fr); }
.steps-wrap::before {
  content: ''; position: absolute; top: 28px;
  left: calc(12.5% + 14px); right: calc(12.5% + 14px);
  height: 2px; background: linear-gradient(90deg, var(--p1), var(--p2)); opacity: 0.15;
}
.steps-wrap.steps-3::before { left: calc(16.6% + 14px); right: calc(16.6% + 14px); }
.step-item { padding: 0 16px; text-align: center; }
.step-num {
  width: 56px; height: 56px; background: var(--grad-main); border-radius: 50%;
  display: flex; align-items: center; justify-content: center; font-size: 22px;
  margin: 0 auto 16px; box-shadow: 0 6px 16px rgba(79,70,229,0.25); position: relative; z-index: 1;
}
.step-title { font-size: 14px; font-weight: 800; color: var(--t-dark); margin-bottom: 8px; }
.step-desc { font-size: 12px; color: var(--t-sub); line-height: 1.85; }

/* ══════════════════════════════
   功能优势
══════════════════════════════ */
.adv-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.adv-item {
  display: flex; gap: 14px; padding: 20px;
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: var(--r-xl); transition: all 0.25s;
}
.adv-item:hover { background: white; box-shadow: var(--shadow-md); border-color: var(--border-l); transform: translateY(-2px); }
.adv-icon {
  width: 44px; height: 44px; border-radius: var(--r-lg);
  display: flex; align-items: center; justify-content: center; font-size: 20px; flex-shrink: 0;
}
.adv-icon-1 { background: linear-gradient(135deg, rgba(245,158,11,0.12), rgba(239,68,68,0.06)); }
.adv-icon-2 { background: linear-gradient(135deg, rgba(16,185,129,0.12), rgba(14,165,233,0.06)); }
.adv-icon-3 { background: linear-gradient(135deg, rgba(79,70,229,0.12), rgba(124,58,237,0.06)); }
.adv-icon-4 { background: linear-gradient(135deg, rgba(14,165,233,0.12), rgba(59,130,246,0.06)); }
.adv-icon-5 { background: linear-gradient(135deg, rgba(239,68,68,0.12), rgba(245,158,11,0.06)); }
.adv-icon-6 { background: linear-gradient(135deg, rgba(16,185,129,0.12), rgba(79,70,229,0.06)); }
.adv-title { font-size: 14px; font-weight: 800; color: var(--t-dark); margin-bottom: 5px; }
.adv-desc { font-size: 12px; color: var(--t-sub); line-height: 1.85; }

/* ══════════════════════════════
   CTA Banner
══════════════════════════════ */
.cta-banner {
  background: linear-gradient(135deg, #f0f4ff 0%, #faf5ff 100%);
  border: 1.5px solid rgba(79,70,229,0.15); border-radius: var(--r-2xl);
  padding: 48px 40px; text-align: center; position: relative; overflow: hidden;
}
.cta-banner::before {
  content: ''; position: absolute; top: -80px; right: -80px;
  width: 250px; height: 250px;
  background: radial-gradient(circle, rgba(79,70,229,0.08) 0%, transparent 70%);
  border-radius: 50%;
}
.cta-title { font-size: 28px; font-weight: 900; color: var(--t-dark); margin-bottom: 10px; letter-spacing: -0.5px; }
.cta-desc { font-size: 14px; color: var(--t-sub); margin-bottom: 24px; }
.cta-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ══════════════════════════════
   页脚
══════════════════════════════ */
.footer { background: var(--t-dark); color: #94a3b8; }
.footer-inner { max-width: 1100px; margin: 0 auto; padding: 0 40px; }
.footer-top {
  display: flex; justify-content: space-between; align-items: center;
  padding: 32px 0; border-bottom: 1px solid rgba(255,255,255,0.08);
}
.footer-logo-name { font-size: 18px; font-weight: 900; color: white; margin-bottom: 3px; }
.footer-logo-sub { font-size: 12px; color: #64748b; }
.footer-links { display: flex; gap: 20px; }
.footer-links a { font-size: 13px; color: #64748b; transition: color 0.2s; }
.footer-links a:hover { color: white; }
.footer-bottom { padding: 16px 0; font-size: 12px; color: #475569; text-align: center; }

/* ══════════════════════════════
   论文生成页 — 横向布局
══════════════════════════════ */
/* 参数行 */
.paper-params-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  gap: 16px;
  margin-bottom: 16px;
}
.paper-params-row-2 {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 16px;
  margin-bottom: 16px;
}
.paper-params-full { margin-bottom: 16px; }

/* 结果区 */
.result-area { min-height: 400px; padding: 20px; }
.empty-box {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  min-height: 280px; gap: 12px;
}
.empty-icon { font-size: 44px; opacity: 0.25; }
.empty-text { font-size: 13px; color: var(--t-muted); text-align: center; line-height: 1.8; }
.loading-box {
  display: flex; align-items: center; justify-content: center; gap: 14px; min-height: 200px;
}

/* Markdown 渲染 */
.md-render { font-size: 15px; line-height: 1.9; color: var(--t-main); word-break: break-word; overflow-wrap: break-word; }
/* 论文题目（H1）*/
.md-render h1, .md-h1 {
  font-size: 22px; font-weight: 900; color: var(--t-dark);
  margin: 28px 0 16px; text-align: center;
  border-bottom: 2px solid var(--border); padding-bottom: 10px;
  text-indent: 0; letter-spacing: 0.05em;
}
/* 一级标题（H2）*/
.md-render h2, .md-h2 {
  font-size: 18px; font-weight: 800; color: var(--t-dark);
  margin: 24px 0 12px;
  padding: 6px 12px;
  background: linear-gradient(90deg, rgba(79,70,229,0.08) 0%, transparent 100%);
  border-left: 4px solid var(--p1);
  border-radius: 0 4px 4px 0;
  text-indent: 0;
}
/* 二级标题（H3）*/
.md-render h3, .md-h3 {
  font-size: 16px; font-weight: 700; color: var(--t-dark);
  margin: 18px 0 8px; padding-left: 8px;
  border-left: 2px solid var(--border-l);
  text-indent: 0;
}
/* 三级标题（H4）*/
.md-render h4, .md-h4 {
  font-size: 15px; font-weight: 700; color: var(--t-sub);
  margin: 14px 0 6px; text-indent: 0;
}
/* 正文段落 */
.md-render p, .md-p {
  margin-bottom: 12px; text-indent: 2em; line-height: 1.9;
  font-size: 15px; color: var(--t-main);
}
.md-render strong { font-weight: 700; color: var(--t-dark); }
.md-render em { font-style: italic; }
.md-render blockquote { border-left: 3px solid var(--p1); padding: 6px 14px; background: var(--p-light); border-radius: 0 var(--r) var(--r) 0; margin: 10px 0; color: var(--p1); }
.md-render ul { padding-left: 18px; margin-bottom: 10px; }
.md-render li { margin-bottom: 3px; }
.md-render hr { border: none; border-top: 1px solid var(--border); margin: 16px 0; }

/* 论文生成结果操作按鈕区 */
.result-action-btns {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
  flex-shrink: 0;
}

/* 手机端结果区域 panel-head 自动换行 */
@media (max-width: 768px) {
  #resultPanel .panel-head {
    flex-wrap: wrap;
    gap: 8px;
    padding: 12px 14px;
  }
  #resultPanel .panel-head-left {
    flex: 1 1 100%;
  }
  .result-action-btns {
    flex: 1 1 100%;
    justify-content: flex-start;
    gap: 6px;
  }
  .result-action-btns .btn-sm {
    padding: 6px 12px;
    font-size: 12px;
  }
  .md-render, .md-h1, .md-h2, .md-h3, .md-h4, .md-p {
    font-size: 14px;
  }
  .md-h1 { font-size: 17px; }
  .md-h2 { font-size: 15px; }
  .md-h3 { font-size: 14px; }
  .result-area {
    padding: 12px 14px;
    min-height: 280px;
  }
}

/* 波形动画 */
.wave-bars { display: flex; align-items: center; gap: 3px; }
.wave-bars span {
  display: block; width: 3px; height: 14px; background: var(--p1);
  border-radius: var(--r-full); animation: wave 1.2s ease-in-out infinite;
}
.wave-bars span:nth-child(2) { animation-delay: 0.1s; }
.wave-bars span:nth-child(3) { animation-delay: 0.2s; }
.wave-bars span:nth-child(4) { animation-delay: 0.3s; }
.wave-bars span:nth-child(5) { animation-delay: 0.4s; }
@keyframes wave {
  0%, 100% { transform: scaleY(0.4); opacity: 0.5; }
  50% { transform: scaleY(1); opacity: 1; }
}

/* ══════════════════════════════
   查重 / AIGC 页 — 横向布局
══════════════════════════════ */
/* 输入区横向 */
.input-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 16px;
  align-items: start;
}
.input-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-top: 2px;
  min-width: 140px;
}
/* 上传按钮 */
.upload-btn {
  display: flex; align-items: center; gap: 6px;
  padding: 9px 14px; background: var(--bg2);
  border: 1.5px dashed var(--border); border-radius: var(--r);
  font-size: 12px; font-weight: 600; color: var(--t-sub);
  cursor: pointer; transition: all 0.2s; width: 100%;
  justify-content: center;
}
.upload-btn:hover { border-color: var(--p1); color: var(--p1); background: var(--p-light); }
input[type="file"] { display: none; }

/* 查重报告 */
.rate-overview {
  display: flex; align-items: center; gap: 20px;
  padding: 20px; background: var(--bg2); border-bottom: 1px solid var(--border);
}
.donut-wrap { position: relative; flex-shrink: 0; }
.donut-svg { transform: rotate(-90deg); }
.donut-bg { fill: none; stroke: var(--bg3); stroke-width: 10; }
.donut-fill { fill: none; stroke-width: 10; stroke-linecap: round; transition: stroke-dashoffset 1.5s ease; }
.donut-center {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); text-align: center;
}
.donut-num { font-size: 18px; font-weight: 900; }
.donut-label { font-size: 9px; color: var(--t-muted); font-weight: 600; }
.risk-badge {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 3px 10px; border-radius: var(--r-full); font-size: 11px; font-weight: 700; margin-bottom: 6px;
}
.risk-low { background: rgba(16,185,129,0.1); color: #10b981; border: 1px solid rgba(16,185,129,0.25); }
.risk-medium { background: rgba(245,158,11,0.1); color: #f59e0b; border: 1px solid rgba(245,158,11,0.25); }
.risk-high { background: rgba(239,68,68,0.1); color: #ef4444; border: 1px solid rgba(239,68,68,0.25); }
.rate-title { font-size: 15px; font-weight: 800; color: var(--t-dark); margin-bottom: 3px; }
.rate-summary { font-size: 12px; color: var(--t-sub); line-height: 1.7; }
.report-block { padding: 14px 20px; border-bottom: 1px solid var(--border); }
.report-block:last-child { border-bottom: none; }
.report-block-title { font-size: 12px; font-weight: 800; color: var(--t-dark); margin-bottom: 10px; }
.risk-sent {
  display: flex; gap: 8px; padding: 8px 10px;
  background: rgba(239,68,68,0.04); border-left: 3px solid #ef4444;
  border-radius: 0 var(--r) var(--r) 0; font-size: 12px; color: var(--t-main);
  margin-bottom: 6px; line-height: 1.7;
}
.chap-item { margin-bottom: 12px; }
.chap-header { display: flex; justify-content: space-between; margin-bottom: 4px; }
.chap-name { font-size: 12px; font-weight: 600; color: var(--t-main); }
.chap-rate { font-size: 12px; font-weight: 800; }
.chap-bar { height: 5px; background: var(--bg3); border-radius: var(--r-full); overflow: hidden; margin-bottom: 3px; }
.chap-fill { height: 100%; border-radius: var(--r-full); transition: width 1s ease; }
.chap-low { background: #10b981; } .chap-medium { background: #f59e0b; } .chap-high { background: #ef4444; }
.chap-reason { font-size: 11px; color: var(--t-muted); }
.suggest-item {
  display: flex; gap: 10px; padding: 8px 0;
  border-bottom: 1px solid var(--border); font-size: 12px; color: var(--t-sub); line-height: 1.7;
}
.suggest-item:last-child { border-bottom: none; }
.suggest-num {
  width: 20px; height: 20px; background: var(--p-light); color: var(--p1);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  font-size: 10px; font-weight: 800; flex-shrink: 0; margin-top: 1px;
}

/* AIGC 降重 — 强度选择 */
.level-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.level-card {
  padding: 16px; background: var(--bg2); border: 2px solid var(--border);
  border-radius: var(--r-xl); text-align: left; cursor: pointer; transition: all 0.2s;
}
.level-card:hover { border-color: var(--border-l); background: white; }
.level-card.active { border-color: var(--p1); background: white; box-shadow: 0 0 0 3px rgba(79,70,229,0.08); }
.level-icon { font-size: 24px; margin-bottom: 8px; }
.level-name { font-size: 14px; font-weight: 800; color: var(--t-dark); margin-bottom: 4px; display: flex; align-items: center; gap: 6px; }
.level-desc { font-size: 11px; color: var(--t-sub); line-height: 1.7; }

/* AIGC 对比区 */
.compare-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0; }
.compare-pane { border-right: 1px solid var(--border); }
.compare-pane:last-child { border-right: none; }
.compare-pane-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 10px 14px; background: var(--bg2); border-bottom: 1px solid var(--border);
  font-size: 12px; font-weight: 700; color: var(--t-main);
}

/* ══════════════════════════════
   Toast
══════════════════════════════ */
.toast {
  position: fixed; bottom: 24px; right: 24px;
  padding: 11px 18px; border-radius: var(--r-lg);
  font-size: 13px; font-weight: 600; color: white;
  z-index: 9999; box-shadow: var(--shadow-lg); transition: opacity 0.3s; max-width: 300px;
}
.toast-success { background: #10b981; }
.toast-error { background: #ef4444; }
.toast-info { background: var(--p1); }

/* ══════════════════════════════
   首页特有样式
══════════════════════════════ */
.hero-section {
  padding: 56px 40px 48px;
  background: linear-gradient(180deg, #fafbff 0%, #f0f4ff 50%, #f8fafc 100%);
  border-bottom: 1px solid var(--border);
  position: relative; overflow: hidden;
}
.hero-bg-grid {
  position: absolute; inset: 0;
  background-image: linear-gradient(rgba(79,70,229,0.04) 1px, transparent 1px), linear-gradient(90deg, rgba(79,70,229,0.04) 1px, transparent 1px);
  background-size: 48px 48px;
}
.hero-bg-orb {
  position: absolute; border-radius: 50%; filter: blur(80px); pointer-events: none;
}
.hero-badge {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 5px 12px; background: rgba(79,70,229,0.08);
  border: 1px solid rgba(79,70,229,0.2); border-radius: var(--r-full);
  font-size: 11px; font-weight: 600; color: var(--p1); margin-bottom: 20px;
}
.hero-badge-dot { width: 6px; height: 6px; background: var(--p1); border-radius: 50%; animation: pulse 2s infinite; }
@keyframes pulse { 0%,100%{opacity:1;transform:scale(1)} 50%{opacity:0.5;transform:scale(0.8)} }
.hero-title {
  font-size: 48px; font-weight: 900; line-height: 1.15; color: var(--t-dark);
  letter-spacing: -1.5px; margin-bottom: 16px;
}
.hero-desc { font-size: 15px; color: var(--t-sub); line-height: 1.8; margin-bottom: 28px; max-width: 560px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 36px; }
.hero-stats { display: flex; gap: 0; flex-wrap: wrap; }
.stat-item { display: flex; flex-direction: column; gap: 2px; padding-right: 20px; }
.stat-num { font-size: 20px; font-weight: 900; color: var(--t-dark); letter-spacing: -0.5px; }
.stat-label { font-size: 11px; color: var(--t-muted); font-weight: 500; }
.feat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feat-card {
  display: flex; flex-direction: column; padding: 28px;
  background: white; border: 1.5px solid var(--border); border-radius: var(--r-2xl);
  box-shadow: var(--shadow-sm); transition: all 0.3s; cursor: pointer; position: relative; overflow: hidden;
}
.feat-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: var(--grad-main); transform: scaleX(0); transform-origin: left; transition: transform 0.3s;
}
.feat-card:hover { border-color: var(--border-l); transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.feat-card:hover::before { transform: scaleX(1); }
.feat-icon-wrap { width: 48px; height: 48px; border-radius: var(--r-xl); display: flex; align-items: center; justify-content: center; font-size: 22px; margin-bottom: 16px; }
.feat-icon-1 { background: linear-gradient(135deg, rgba(79,70,229,0.1), rgba(124,58,237,0.06)); }
.feat-icon-2 { background: linear-gradient(135deg, rgba(14,165,233,0.1), rgba(99,102,241,0.06)); }
.feat-icon-3 { background: linear-gradient(135deg, rgba(16,185,129,0.1), rgba(14,165,233,0.06)); }
.feat-num { font-size: 10px; font-weight: 800; color: var(--t-muted); letter-spacing: 1px; margin-bottom: 6px; }
.feat-name { font-size: 18px; font-weight: 800; color: var(--t-dark); margin-bottom: 10px; }
.feat-desc { font-size: 13px; color: var(--t-sub); line-height: 1.8; flex: 1; margin-bottom: 14px; }
.feat-tags { display: flex; flex-wrap: wrap; gap: 5px; margin-bottom: 16px; }
.feat-tag { font-size: 10px; padding: 2px 8px; background: var(--bg2); border: 1px solid var(--border); border-radius: var(--r-full); color: var(--t-sub); font-weight: 600; }
.feat-arrow { display: flex; align-items: center; gap: 5px; font-size: 12px; font-weight: 700; color: var(--p1); }

/* ══════════════════════════════
   手机底部导航栏
══════════════════════════════ */
.bottom-nav {
  display: none;
  position: fixed; bottom: 0; left: 0; right: 0;
  height: calc(var(--bottom-nav-h) + env(safe-area-inset-bottom, 0px));
  background: white; border-top: 1px solid var(--border);
  z-index: 200; box-shadow: 0 -4px 16px rgba(0,0,0,0.06);
  padding-bottom: env(safe-area-inset-bottom, 0px);
  box-sizing: border-box;
}
.bottom-nav-inner {
  display: flex;
  width: 100%;
  height: var(--bottom-nav-h);
  align-items: stretch;
}
.bottom-nav-item {
  flex: 1 1 0;
  min-width: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 3px; font-size: 10px; font-weight: 600; color: var(--t-muted);
  cursor: pointer; transition: color 0.2s; text-decoration: none;
  border: none; background: none;
  padding: 0 4px;
  white-space: nowrap;
  overflow: hidden;
}
.bottom-nav-item.active { color: var(--p1); }
.bottom-nav-item:hover { color: var(--p1); }
.bottom-nav-icon { font-size: 20px; line-height: 1; flex-shrink: 0; }

/* ══════════════════════════════
   响应式
══════════════════════════════ */
@media (max-width: 768px) {
  :root { --sidebar-w: 0px; }
  body { padding-left: 0; padding-bottom: calc(var(--bottom-nav-h) + env(safe-area-inset-bottom, 0px)); }
  .sidebar { display: none; }
  .bottom-nav { display: block; }

  /* 页面顶部标题区 */
  .page-hero { padding: 20px 16px 18px; }
  .page-hero h1 { font-size: 22px; letter-spacing: -0.5px; }
  .page-hero-desc { font-size: 13px; }

  /* 页面内容区 */
  .page-body { padding: 12px 12px 80px; }

  /* 首页英雄区 */
  .hero-section { padding: 24px 16px 20px; }
  .hero-title { font-size: 26px; letter-spacing: -0.8px; }
  .hero-desc { font-size: 13px; margin-bottom: 20px; }
  .hero-actions { gap: 8px; margin-bottom: 24px; }
  .hero-stats { gap: 0; }
  .stat-item { padding-right: 14px; }
  .stat-num { font-size: 16px; }

  /* 功能卡片 */
  .feat-grid { grid-template-columns: 1fr; gap: 12px; }
  .feat-card { padding: 20px; }

  /* 优势列表 */
  .adv-grid { grid-template-columns: 1fr; gap: 10px; }
  .adv-item { padding: 14px; }

  /* 步骤 */
  .steps-wrap { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .steps-wrap::before { display: none; }
  .step-item { padding: 0 8px; }
  .step-num { width: 44px; height: 44px; font-size: 18px; margin-bottom: 10px; }
  .step-title { font-size: 13px; }
  .step-desc { font-size: 11px; }

  /* Section 标题 */
  .sec-title { font-size: 22px; }
  .sec-desc { font-size: 13px; }

  /* Panel */
  .panel-body { padding: 14px; }
  .panel-head { padding: 12px 14px; }

  /* 论文生成页参数 */
  .paper-params-row { grid-template-columns: 1fr 1fr; gap: 10px; }
  .paper-params-row-2 { grid-template-columns: 1fr 1fr; gap: 10px; }

  /* 查重/降重输入区 */
  .input-row { grid-template-columns: 1fr; gap: 10px; }
  .input-actions {
    flex-direction: row;
    flex-wrap: wrap;
    min-width: unset;
    gap: 8px;
  }
  .input-actions .btn { flex: 1; min-width: calc(50% - 4px); justify-content: center; }
  .upload-btn { flex: 1; }

  /* 强度选择卡片 */
  .level-row { grid-template-columns: 1fr; gap: 8px; }
  .level-card { padding: 12px 14px; display: flex; align-items: center; gap: 12px; }
  .level-icon { font-size: 20px; margin-bottom: 0; flex-shrink: 0; }
  .level-name { font-size: 13px; margin-bottom: 2px; }
  .level-desc { font-size: 11px; }

  /* 对比区 */
  .compare-grid { grid-template-columns: 1fr; }
  .compare-pane { border-right: none; border-bottom: 1px solid var(--border); }

  /* CTA */
  .cta-banner { padding: 24px 16px; }
  .cta-title { font-size: 20px; }
  .cta-actions { flex-direction: column; align-items: center; }

  /* 页脚 */
  .footer-inner { padding: 0 16px; }
  .footer-top { flex-direction: column; gap: 12px; text-align: center; }
  .footer-links { justify-content: center; flex-wrap: wrap; }

  /* Toast */
  .toast { bottom: calc(var(--bottom-nav-h) + 12px); right: 12px; left: 12px; max-width: unset; }

  /* 查重报告 */
  .rate-overview { flex-direction: column; align-items: flex-start; gap: 12px; padding: 14px; }
  .report-block { padding: 12px 14px; }

  /* 按钮 */
  .btn-lg { padding: 11px 20px; font-size: 14px; }
  .btn-primary { padding: 11px 20px; font-size: 13px; }

  /* 结果区 */
  .result-area { min-height: 280px; padding: 12px 14px; }
  .md-render { font-size: 14px; }
  .result-text { font-size: 13px; padding: 14px; }
}
@media (min-width: 769px) and (max-width: 1100px) {
  :root { --sidebar-w: 200px; }
  .paper-params-row { grid-template-columns: 1fr 1fr; }
}

/* ══════════════════════════════
   强度选择卡片（AIGC降重）
══════════════════════════════ */
.strength-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}
.strength-card {
  padding: 16px 18px;
  background: var(--bg2);
  border: 2px solid var(--border);
  border-radius: var(--r-xl);
  cursor: pointer;
  transition: all 0.2s;
}
.strength-card:hover { border-color: var(--border-l); background: white; }
.strength-card.active {
  border-color: var(--p1);
  background: white;
  box-shadow: 0 0 0 3px rgba(79,70,229,0.08);
}
.strength-icon { font-size: 24px; margin-bottom: 8px; }
.strength-name { font-size: 14px; font-weight: 800; color: var(--t-dark); margin-bottom: 4px; }
.strength-desc { font-size: 11px; color: var(--t-sub); line-height: 1.7; }
.strength-badge {
  display: inline-block;
  font-size: 9px; padding: 1px 7px;
  background: var(--grad-btn); color: white;
  border-radius: var(--r-full); font-weight: 700; margin-left: 4px;
}

/* 结果文本区 */
.result-text {
  white-space: pre-wrap;
  line-height: 1.9;
  font-size: 15px;
  color: var(--t-main);
  padding: 20px;
}

@media (max-width: 768px) {
  .strength-cards { grid-template-columns: 1fr; }
}