:root {
  --primary: #2b4cdf;
  --primary-dark: #1e37a8;
  --primary-light: #eef2ff;
  --accent: #6d3bdf;
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #e5e7eb;
  --success: #16a34a;
  --danger: #dc2626;
  --warn: #d97706;
  --radius: 12px;
  --shadow: 0 2px 12px rgba(43, 76, 223, 0.08);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  background: var(--bg); color: var(--text); line-height: 1.6; font-size: 15px;
  -webkit-text-size-adjust: 100%;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { max-width: 1120px; margin: 0 auto; padding: 0 16px; }
.hidden { display: none !important; }

/* 顶部导航 */
.nav { background: #fff; border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 50; }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 58px; }
.brand { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 17px; color: var(--primary); }
.brand .logo { width: auto; min-width: 30px; height: 30px; padding: 0 5px; border-radius: 8px; background: linear-gradient(135deg, var(--primary), var(--accent)); color: #fff; display: grid; place-items: center; font-weight: 800; font-size: 14px; letter-spacing: 0; }
.nav-links { display: flex; gap: 4px; align-items: center; flex-wrap: wrap; }
.nav-links a { padding: 8px 12px; border-radius: 8px; color: var(--text); font-size: 14px; }
.nav-links .btn:not(.btn-secondary):not(.btn-ghost) { color: #fff; }
.nav-links a:hover { background: var(--primary-light); text-decoration: none; }
.nav-links a.active { color: var(--primary); font-weight: 600; }
.nav-user { display: flex; align-items: center; gap: 10px; }
.email-badge { font-size: 13px; color: var(--muted); }
.balance-badge { display: inline-flex; align-items: center; gap: 4px; padding: 4px 10px; border-radius: 999px; font-size: 12px; font-weight: 600; color: var(--primary); background: var(--primary-light); text-decoration: none; }
.balance-badge:hover { text-decoration: none; filter: brightness(.96); }
.balance-badge.balance-low { color: #b45309; background: #fef3c7; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 9px 16px; border-radius: 9px; border: 1px solid transparent; cursor: pointer;
  font-size: 14px; font-weight: 600; transition: .15s; background: var(--primary); color: #fff;
}
.btn:hover { background: var(--primary-dark); }
.btn:disabled { opacity: .55; cursor: not-allowed; }
.btn-secondary { background: #fff; color: var(--primary); border-color: var(--border); }
.btn-secondary:hover { background: var(--primary-light); }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--border); }
.btn-ghost:hover { background: #f1f3f9; }
.btn-danger { background: var(--danger); }
.btn-sm { padding: 6px 12px; font-size: 13px; }
.btn-block { width: 100%; }

/* 卡片/区块 */
.card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); }
.section { padding: 40px 0; }
.section-title { font-size: 24px; font-weight: 800; margin-bottom: 8px; }
.section-sub { color: var(--muted); margin-bottom: 24px; }
.grid { display: grid; gap: 16px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* 首页 Hero */
.hero { background: linear-gradient(135deg, #2b4cdf 0%, #6d3bdf 100%); color: #fff; padding: 64px 0 56px; }
.hero h1 { font-size: 38px; font-weight: 800; line-height: 1.25; margin-bottom: 16px; }
.hero p { font-size: 17px; opacity: .92; max-width: 640px; margin-bottom: 24px; }
.hero .btn { background: #fff; color: var(--primary); }
.hero .btn:hover { background: #f0f3ff; }

/* 表单 */
label { display: block; font-size: 13px; font-weight: 600; margin: 14px 0 6px; color: #374151; }
input, textarea, select {
  width: 100%; padding: 10px 12px; border: 1px solid var(--border); border-radius: 9px;
  font-size: 14px; font-family: inherit; background: #fff; color: var(--text);
}
input:focus, textarea:focus, select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-light); }
textarea { resize: vertical; min-height: 90px; line-height: 1.6; }
.field-hint { font-size: 12px; color: var(--muted); margin-top: 4px; }
.char-count { float: right; font-size: 12px; color: var(--muted); font-weight: 400; }

/* 徽章/标签 */
.badge { display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 12px; font-weight: 600; background: var(--primary-light); color: var(--primary); }
.badge-green { background: #dcfce7; color: var(--success); }
.badge-gray { background: #f1f3f9; color: var(--muted); }
.badge-red { background: #fee2e2; color: var(--danger); }
.badge-orange { background: #ffedd5; color: var(--warn); }

/* 提示条 */
.alert { padding: 12px 14px; border-radius: 9px; font-size: 14px; margin: 12px 0; }
.alert-info { background: var(--primary-light); color: var(--primary-dark); }
.alert-warn { background: #fff7ed; color: var(--warn); border: 1px solid #fed7aa; }
.alert-danger { background: #fef2f2; color: var(--danger); border: 1px solid #fecaca; }

/* 步骤条 */
.steps { display: flex; gap: 8px; margin-bottom: 24px; }
.step { flex: 1; padding: 12px; border-radius: 10px; background: #fff; border: 1px solid var(--border); text-align: center; font-size: 13px; color: var(--muted); }
.step.active { border-color: var(--primary); color: var(--primary); font-weight: 700; background: var(--primary-light); }
.step.done { border-color: var(--success); color: var(--success); }

/* 素材块 */
.material-box { border: 1px solid var(--border); border-radius: 10px; padding: 14px; margin-bottom: 14px; background: #fafbff; }
.material-box .m-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
.material-box .m-head b { font-size: 14px; }

/* 分析结果 */
.analysis-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.analysis-item { background: #fafbff; border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; }
.analysis-item h4 { font-size: 13px; color: var(--primary); margin-bottom: 4px; }
.analysis-item p { font-size: 14px; color: var(--text); white-space: pre-wrap; }
.sub { font-size: 13px; font-weight: 700; color: var(--text); margin: 16px 0 8px; }
.kv-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
.kv { background: #fafbff; border: 1px solid var(--border); border-radius: 10px; padding: 10px 12px; }
.kv .k { display: block; font-size: 12px; color: var(--primary); font-weight: 600; margin-bottom: 3px; }
.kv .v { font-size: 14px; color: var(--text); white-space: pre-wrap; }
.dna-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
.dna-item { background: linear-gradient(180deg, #f7f9ff, #fff); border: 1px solid var(--border); border-left: 3px solid var(--primary); border-radius: 8px; padding: 8px 12px; }
.dna-k { display: block; font-size: 12px; font-weight: 700; color: var(--primary); margin-bottom: 2px; }
.dna-v { font-size: 13px; color: var(--text); white-space: pre-wrap; }
.chip-wrap { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { display: inline-block; padding: 4px 10px; border-radius: 999px; font-size: 13px; border: 1px solid transparent; }
.chip-good { background: #ecfdf5; color: #047857; border-color: #a7f3d0; }
.chip-bad { background: #fef2f2; color: #b91c1c; border-color: #fecaca; }
.sample-block { border: 1px solid var(--border); border-radius: 12px; padding: 12px 14px; margin-bottom: 12px; background: #fff; }
.sample-title { font-weight: 700; color: var(--text); margin-bottom: 8px; font-size: 14px; }
.topic-card { border: 1px solid var(--border); border-radius: 10px; padding: 14px; margin-bottom: 12px; cursor: pointer; transition: .15s; }
.topic-card:hover { border-color: var(--primary); }
.topic-card.selected { border-color: var(--primary); background: var(--primary-light); }
.topic-card .t-score { float: right; font-weight: 800; color: var(--accent); }
.topic-card .t-title { font-weight: 700; margin-bottom: 4px; }
.topic-card .t-meta { font-size: 12px; color: var(--muted); }
.topic-card.recommended { box-shadow: 0 0 0 2px var(--accent) inset; }

/* 文章结果 */
.article-title { font-size: 22px; font-weight: 800; margin-bottom: 12px; line-height: 1.4; }
.article-body { white-space: pre-wrap; line-height: 1.9; font-size: 16px; color: #222; background: #fff; border: 1px solid var(--border); border-radius: 10px; padding: 20px; max-height: 520px; overflow: auto; }
.result-meta { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }

/* 表格 */
table { width: 100%; border-collapse: collapse; font-size: 13px; }
th, td { text-align: left; padding: 10px 8px; border-bottom: 1px solid var(--border); }
th { color: var(--muted); font-weight: 600; background: #fafbff; }
.table-wrap { overflow-x: auto; }

/* 弹窗 */
.modal-mask { position: fixed; inset: 0; background: rgba(15, 23, 42, .5); display: none; z-index: 100; }
.modal-mask.show { display: flex; align-items: center; justify-content: center; padding: 16px; }
.modal { background: #fff; border-radius: 14px; max-width: 720px; width: 100%; max-height: 88vh; overflow: auto; padding: 22px; }
.modal h3 { margin-bottom: 12px; }

/* toast */
.toast-wrap { position: fixed; top: 16px; left: 50%; transform: translateX(-50%); z-index: 200; display: flex; flex-direction: column; gap: 8px; align-items: center; }
.toast { background: #1f2937; color: #fff; padding: 10px 18px; border-radius: 10px; font-size: 14px; box-shadow: 0 6px 20px rgba(0,0,0,.2); animation: pop .2s; }
.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }
@keyframes pop { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; } }

/* 加载 */
.spinner { width: 18px; height: 18px; border: 3px solid rgba(255,255,255,.4); border-top-color: #fff; border-radius: 50%; animation: spin .7s linear infinite; display: inline-block; }
.spinner-dark { border-color: rgba(43,76,223,.25); border-top-color: var(--primary); }
@keyframes spin { to { transform: rotate(360deg); } }
.loading-block { text-align: center; padding: 40px; color: var(--muted); }

/* 页脚 */
.footer { background: #111827; color: #cbd5e1; padding: 36px 0; margin-top: 40px; font-size: 13px; }
.footer a { color: #cbd5e1; }
.footer .links { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 12px; }

/* 桌面端隐藏手机专用元素（必须在媒体查询之前，否则会被后面的全局 display:none 覆盖） */
.menu-toggle { display: none; background: none; border: none; font-size: 22px; cursor: pointer; }
.nav-mobile-actions { display: none; }

/* 响应式 */
@media (max-width: 860px) {
  /* iOS Safari：输入框字号 <16px 时聚焦会自动放大页面，统一提到 16px 防止误缩放 */
  input, textarea, select { font-size: 16px; }
  .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
  .analysis-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 28px; }

  /* 导航栏：手机端显示汉堡菜单 + 关键快捷入口 */
  .nav-links { display: none; }
  .nav-links.open {
    display: flex; flex-direction: column;
    position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(15,23,42,.45); z-index: 200;
    padding: 0;
  }
  .nav-links.open::before {
    content: '';
    position: absolute; top: 0; left: 0; right: 0;
    height: 100vh;
    background: #fff;
    border-radius: 0 0 16px 16px;
    padding-top: 8px;
  }
  /* 菜单内容容器（在伪元素之上） */
  .nav-links.open > a,
  .nav-links.open > .nav-user {
    position: relative; z-index: 201;
    padding: 14px 20px;
    font-size: 16px;
    border-bottom: 1px solid #f0f0f5;
    color: var(--text);
  }
  .nav-links.open > a:hover,
  .nav-links.open > a.active {
    background: var(--primary-light);
    text-decoration: none;
  }
  .nav-links.open > .nav-user {
    border-bottom: none;
    padding: 16px 20px;
    gap: 10px;
    flex-wrap: wrap;
  }
  .menu-toggle {
    display: inline-flex; align-items: center; justify-content: center;
    width: 42px; height: 42px; border-radius: 10px;
    font-size: 22px; cursor: pointer;
    background: var(--primary-light); color: var(--primary);
    border: none; transition: all .15s;
  }
  .menu-toggle:hover { background: var(--primary); color: #fff; }
  /* 手机端导航栏右侧快捷按钮区 */
  .nav-mobile-actions { display: flex; align-items: center; gap: 6px; }
}
.stat-card { text-align: center; }
.stat-card .num { font-size: 26px; font-weight: 800; color: var(--primary); }
.stat-card .lbl { font-size: 13px; color: var(--muted); }
.tabs { display: flex; gap: 6px; border-bottom: 1px solid var(--border); margin-bottom: 18px; flex-wrap: wrap; }
.tab { padding: 10px 14px; cursor: pointer; border-bottom: 2px solid transparent; color: var(--muted); font-size: 14px; }
.tab.active { color: var(--primary); border-bottom-color: var(--primary); font-weight: 600; }
.tab-content { display: none; }
.tab-content.active { display: block; }
.pagination { display: flex; gap: 8px; justify-content: center; margin-top: 16px; align-items: center; }
.qr-placeholder { width: 160px; height: 160px; border: 2px dashed var(--border); border-radius: 10px; display: grid; place-items: center; color: var(--muted); font-size: 13px; text-align: center; }
.code-box { font-family: ui-monospace, Menlo, Consolas, monospace; background: #f1f3f9; padding: 8px 10px; border-radius: 8px; word-break: break-all; }