/* ==========================================================================
   管理后台 · Carbon 式直角网格（与前台同一套设计语言）
   ========================================================================== */

:root {
  --primary: #1565c0;
  --primary-hover: #0f52a0;
  --primary-press: #0b3f7d;
  --navy: #0d2f57;
  --yellow: #f5b301;
  --yellow-dark: #8a6200;

  --canvas: #ffffff;
  --bg: #f4f4f4;
  --surface: #f4f4f4;
  --hairline: #e0e0e0;
  --hairline-strong: #c6c6c6;

  --ink: #161616;
  --ink-muted: #525252;
  --ink-subtle: #8d8d8d;
  --text: #161616;
  --muted: #525252;
  --line: #e0e0e0;
  --line-strong: #c6c6c6;

  --good: #0e7a5f;
  --bad: #b3261e;
  --radius: 0px;
  --shadow: none;

  --font: "IBM Plex Sans", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --duration-quick: 150ms;
  --duration-fast: 250ms;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--font); background: var(--bg); color: var(--ink); font-size: 14px; line-height: 1.6; letter-spacing: .01em; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
img { display: block; max-width: 100%; }

/* 布局 */
.layout { display: flex; min-height: 100vh; }

.sidebar {
  width: 216px; flex: none; background: #161616; color: #f4f4f4;
  position: sticky; top: 0; height: 100vh; overflow-y: auto;
  display: flex; flex-direction: column;
  border-right: 1px solid #262626;
}
.side-brand { padding: 22px 18px 20px; border-bottom: 1px solid #262626; }
.side-brand .tag {
  display: inline-block; background: var(--yellow); color: #2b1f00; font-size: 10px;
  font-weight: 700; letter-spacing: .1em; padding: 3px 7px; margin-bottom: 10px;
}
.side-brand h1 { font-size: 13.5px; font-weight: 600; line-height: 1.5; color: #fff; text-wrap: balance; }
.side-brand p { font-size: 11px; color: #8d8d8d; margin-top: 6px; }

.side-nav { padding: 10px 8px; flex: 1; }
.side-group { font-size: 10px; letter-spacing: .14em; color: #6f6f6f; padding: 14px 10px 6px; }
.side-nav a {
  display: flex; align-items: center; gap: 9px; padding: 10px 12px;
  font-size: 13px; color: #c6c6c6; border-left: 2px solid transparent;
  transition: background var(--duration-quick), color var(--duration-quick), border-color var(--duration-quick);
}
.side-nav a:hover { background: #262626; color: #fff; }
.side-nav a.active { background: #262626; color: #fff; border-left-color: var(--yellow); font-weight: 500; }
.side-nav a .dot { width: 4px; height: 4px; background: currentColor; opacity: .5; }

.side-foot { padding: 16px; border-top: 1px solid #262626; font-size: 11.5px; color: #8d8d8d; }
.side-foot .who { color: #fff; font-size: 12.5px; font-weight: 500; }
.side-foot .who em { font-style: normal; font-size: 10px; color: var(--yellow); margin-left: 6px; letter-spacing: .08em; }
.side-foot form { margin-top: 10px; }
.side-foot button {
  width: 100%; background: transparent; border: 1px solid #393939;
  color: #c6c6c6; height: 30px; font-size: 12px; transition: all var(--duration-quick);
}
.side-foot button:hover { background: #262626; color: #fff; border-color: #525252; }

.main { flex: 1; min-width: 0; display: flex; flex-direction: column; }
.topbar {
  height: 56px; background: #fff; border-bottom: 1px solid var(--hairline);
  display: flex; align-items: center; justify-content: space-between; padding: 0 24px;
  position: sticky; top: 0; z-index: 20;
}
.topbar h2 { font-size: 16px; font-weight: 600; color: var(--ink); }
.topbar .right { display: flex; align-items: center; gap: 16px; font-size: 12.5px; color: var(--ink-muted); }
.topbar .right a { color: var(--primary); }
.topbar .right a:hover { text-decoration: underline; }

.content { padding: 24px; max-width: 1320px; width: 100%; }

/* 卡片 */
.card { background: #fff; border: 1px solid var(--hairline); }
.card-pad { padding: 20px; }
.card-head { padding: 16px 20px; border-bottom: 1px solid var(--hairline); display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.card-head h3 { font-size: 14.5px; font-weight: 600; color: var(--ink); }
.card-head .sub { font-size: 12px; color: var(--ink-muted); font-weight: 400; margin-left: 6px; }
.card-body { padding: 20px; }

.kpi-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--hairline); border: 1px solid var(--hairline); }
.kpi { background: #fff; padding: 18px 20px; position: relative; }
.kpi .k { font-size: 12px; color: var(--ink-muted); letter-spacing: .04em; }
.kpi .v { font-size: 32px; font-weight: 600; color: var(--ink); letter-spacing: -.02em; margin-top: 4px; font-variant-numeric: tabular-nums; line-height: 1.1; }
.kpi .v small { font-size: 13px; font-weight: 500; color: var(--ink-muted); margin-left: 3px; }
.kpi .d { font-size: 11.5px; color: var(--ink-subtle); margin-top: 6px; }
.kpi.good .v { color: var(--good); }
.kpi.bad .v { color: var(--bad); }
.kpi.yellow .v { color: #8a6200; }

.grid-2 { display: grid; grid-template-columns: 1.55fr 1fr; gap: 14px; margin-top: 14px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }

.section-title { font-size: 13px; font-weight: 600; color: var(--ink); margin: 20px 0 10px; display: flex; align-items: center; gap: 8px; }
.section-title::before { content: ""; width: 2px; height: 13px; background: var(--primary); }

.chart { width: 100%; height: auto; display: block; }
.chart-legend { display: flex; gap: 16px; font-size: 11.5px; color: var(--ink-muted); margin-top: 8px; }
.chart-legend i { display: inline-block; width: 9px; height: 9px; margin-right: 5px; vertical-align: -1px; }

/* 表格 */
.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
table.data { width: 100%; border-collapse: collapse; font-size: 13px; }
table.data.table-wide { min-width: 1040px; }
table.data.table-md { min-width: 760px; }
table.data.table-sm { min-width: 560px; }
table.data th {
  background: var(--surface); color: var(--ink); font-weight: 600; text-align: left; white-space: nowrap;
  padding: 10px 12px; border-bottom: 1px solid var(--hairline-strong); font-size: 12px; letter-spacing: .04em;
}
table.data td { padding: 10px 12px; border-bottom: 1px solid var(--hairline); vertical-align: middle; }
table.data tbody tr:hover td { background: #fafafa; }
table.data tr:last-child td { border-bottom: 0; }
table.data td.num, table.data th.num { font-variant-numeric: tabular-nums; white-space: nowrap; }
table.data .muted { color: var(--ink-muted); }
/* 窄屏时操作列固定在右侧，避免横向滚动找不到按钮 */
table.data th:last-child, table.data td:last-child {
  position: sticky; right: 0; background: #fff; box-shadow: -1px 0 0 var(--hairline);
}
table.data th:last-child { background: var(--surface); }
table.data tbody tr:hover td:last-child { background: #fafafa; }
.empty { padding: 40px 16px; text-align: center; color: var(--ink-subtle); font-size: 13px; }

.tag { display: inline-block; padding: 1px 7px; font-size: 11px; font-weight: 500; white-space: nowrap; border: 1px solid transparent; }
.tag-good { background: #eefaf5; color: var(--good); border-color: #bfe6d8; }
.tag-bad { background: #fdf2f1; color: var(--bad); border-color: #f1cbc6; }
.tag-blue { background: #edf5ff; color: var(--primary); border-color: #c2d9fe; }
.tag-grey { background: #f4f4f4; color: var(--ink-muted); border-color: #e0e0e0; }
.tag-yellow { background: #fff8e1; color: var(--yellow-dark); border-color: #f2e0a8; }

/* 表单 */
.field { margin-bottom: 14px; }
.field label { display: block; font-size: 12px; color: var(--ink-muted); margin-bottom: 5px; font-weight: 500; letter-spacing: .03em; }
.field label .req { color: var(--bad); }
.input, .select, .textarea {
  width: 100%; border: 1px solid var(--hairline-strong); border-radius: 0; background: var(--surface);
  height: 40px; padding: 0 12px; font-size: 13.5px; outline: none;
  transition: background var(--duration-quick), border-color var(--duration-quick), box-shadow var(--duration-quick);
}
.textarea { height: auto; min-height: 76px; padding: 10px 12px; resize: vertical; line-height: 1.65; }
.input:focus, .select:focus, .textarea:focus { background: #fff; border-color: var(--primary); box-shadow: inset 0 -2px 0 var(--primary); }
.field-row { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.field-row-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.form-hint { font-size: 11.5px; color: var(--ink-subtle); margin-top: 5px; line-height: 1.6; }

.toolbar { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 12px; }
.toolbar .field { margin-bottom: 0; }
.toolbar .input, .toolbar .select { width: auto; min-width: 132px; }
.toolbar .field.grow { flex: 1 1 180px; }
.toolbar .field.grow .input { width: 100%; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  height: 40px; padding: 0 16px; border: 1px solid transparent; border-radius: 0;
  font-size: 13px; font-weight: 500; white-space: nowrap;
  transition: background var(--duration-quick), border-color var(--duration-quick), color var(--duration-quick);
}
.btn:active { transform: translateY(1px); }
.btn-blue { background: var(--primary); color: #fff; }
.btn-blue:hover { background: var(--primary-hover); }
.btn-yellow { background: var(--yellow); color: #2b1f00; }
.btn-yellow:hover { background: #ffc21f; }
.btn-line { border-color: var(--hairline-strong); background: #fff; color: var(--ink); }
.btn-line:hover { border-color: var(--primary); color: var(--primary); }
.btn-danger-line { border-color: #e6bdb8; background: #fff; color: var(--bad); }
.btn-danger-line:hover { background: #fdf4f3; }
.btn-sm { height: 32px; padding: 0 10px; font-size: 12.5px; }
.btn-xs { height: 28px; padding: 0 8px; font-size: 12px; }
.btn-block { width: 100%; display: flex; }
.btn:disabled { opacity: .5; cursor: not-allowed; }

.alert { padding: 11px 14px; font-size: 13px; margin-bottom: 14px; border-left: 3px solid; }
.alert-ok { background: #eefaf5; border-color: var(--good); color: #0b5c46; }
.alert-err { background: #fdf2f1; border-color: var(--bad); color: #8c1d18; }
.alert-info { background: #edf5ff; border-color: var(--primary); color: #0b3f7d; }

/* 登录 */
.login-page {
  min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 24px;
  background: #161616; position: relative; overflow: hidden;
}
.login-page::before {
  content: ""; position: absolute; inset: 0;
  background-image: linear-gradient(rgba(255,255,255,.04) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px);
  background-size: 48px 48px;
}
.login-page::after { content: ""; position: absolute; width: 480px; height: 480px; border: 1px solid rgba(245,179,1,.25); border-radius: 50%; right: -160px; top: -200px; }
.login-box { width: 100%; max-width: 392px; background: #fff; padding: 36px 32px; position: relative; z-index: 2; border-top: 4px solid var(--yellow); }
.login-box .brand { margin-bottom: 26px; }
.login-box .tag { display: inline-block; background: var(--yellow); color: #2b1f00; font-weight: 700; font-size: 10px;
  letter-spacing: .12em; padding: 4px 8px; margin-bottom: 12px; }
.login-box h1 { font-size: 19px; color: var(--ink); font-weight: 600; line-height: 1.45; }
.login-box p { font-size: 12px; color: var(--ink-muted); margin-top: 6px; }
.login-box .btn { height: 46px; margin-top: 8px; }
.login-foot { font-size: 11.5px; color: var(--ink-subtle); margin-top: 20px; line-height: 1.8; border-top: 1px solid var(--hairline); padding-top: 16px; }

/* 分页 */
.pager { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 12px 20px; border-top: 1px solid var(--hairline); font-size: 12.5px; color: var(--ink-muted); flex-wrap: wrap; }
.pager .pages { display: flex; gap: 4px; }
.pager a, .pager span {
  min-width: 30px; height: 30px; padding: 0 8px; border: 1px solid var(--hairline-strong);
  display: inline-flex; align-items: center; justify-content: center; background: #fff;
}
.pager a:hover { border-color: var(--primary); color: var(--primary); }
.pager span.current { background: var(--primary); border-color: var(--primary); color: #fff; font-weight: 500; }

/* 二维码 */
.qr-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--hairline); border: 1px solid var(--hairline); }
.qr-item { padding: 14px; text-align: center; background: #fff; }
.qr-item img { width: 100%; height: auto; margin: 0 auto 8px; }
.qr-item .no { font-size: 16px; font-weight: 600; color: var(--ink); font-variant-numeric: tabular-nums; letter-spacing: .06em; }
.qr-item .person { font-size: 11.5px; color: var(--ink-muted); margin-top: 2px; }
.qr-item.unbound { background: #fafafa; }
.qr-item.unbound .no { color: var(--ink-subtle); }

/* 弹窗 */
dialog.modal { border: 0; border-radius: 0; padding: 0; width: min(480px, 92vw); box-shadow: 0 24px 70px rgba(0, 0, 0, .3);
  position: fixed; inset: 0; margin: auto; height: fit-content; max-height: 90vh; overflow: auto; }
dialog.modal::backdrop { background: rgba(22, 22, 22, .6); }
dialog.modal .modal-head { padding: 16px 20px; border-bottom: 1px solid var(--hairline); display: flex; align-items: center; justify-content: space-between; }
dialog.modal .modal-head h3 { font-size: 15px; font-weight: 600; }
dialog.modal .modal-body { padding: 20px; }
dialog.modal .modal-foot { padding: 14px 20px; border-top: 1px solid var(--hairline); display: flex; justify-content: flex-end; gap: 8px; }

/* 关键词条形图 */
.keyword-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.tagbar { display: flex; align-items: center; gap: 10px; margin-bottom: 9px; font-size: 12.5px; }
.tagbar .k { width: 80px; flex: none; color: #3c4a5e; }
.tagbar .bar { flex: 1; height: 8px; background: #f0f0f0; position: relative; }
.tagbar .bar i { position: absolute; left: 0; top: 0; bottom: 0; display: block; }
.tagbar .v { width: 32px; text-align: right; color: var(--ink-muted); font-variant-numeric: tabular-nums; }

/* 响应式 */
@media (max-width: 1080px) {
  .kpi-grid { grid-template-columns: repeat(2, 1fr); }
  .grid-2 { grid-template-columns: 1fr; }
  .qr-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 760px) {
  .layout { flex-direction: column; }
  .sidebar { width: 100%; height: auto; position: static; }
  .side-brand { padding: 14px 16px; }
  .side-brand h1 { font-size: 13px; }
  .side-nav { display: flex; overflow-x: auto; padding: 4px 8px 8px; gap: 2px; }
  .side-group { display: none; }
  .side-nav a { white-space: nowrap; font-size: 12.5px; padding: 8px 11px; border-left: 0; border-bottom: 2px solid transparent; }
  .side-nav a.active { border-left: 0; border-bottom-color: var(--yellow); }
  .side-foot { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 10px 14px; }
  .side-foot form { margin: 0; }
  .side-foot button { width: auto; padding: 0 12px; }
  .content { padding: 14px; }
  .topbar { padding: 0 14px; height: 52px; }
  .grid-3 { grid-template-columns: 1fr; }
  .field-row, .field-row-3 { grid-template-columns: 1fr; }
  .qr-grid { grid-template-columns: repeat(2, 1fr); }
  .toolbar .input, .toolbar .select { min-width: 0; width: 100%; }
  .toolbar .field { flex: 1 1 140px; }
  .keyword-grid { grid-template-columns: 1fr; gap: 18px; }
  .tagbar .k { width: 72px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}

/* ==========================================================================
   登录页 · 左图轮播 + 右表单
   ========================================================================== */

.login-page { background: #08120f; padding: 24px; }
.login-page::before, .login-page::after { display: none; }

.login-shell {
  width: min(1080px, 96vw); height: min(660px, 92vh);
  display: grid; grid-template-columns: 1.12fr .88fr;
  background: #fff; overflow: hidden; border-top: 4px solid var(--yellow);
  box-shadow: 0 40px 100px rgba(0, 0, 0, .55);
}

.login-visual { position: relative; overflow: hidden; background: #123f35; }
.lv-slide {
  position: absolute; inset: 0; background-size: cover; background-position: center;
  opacity: 0; will-change: opacity, transform;
  animation: lvFade 35s linear infinite;
  animation-delay: calc(var(--i) * 5s);
}
@keyframes lvFade {
  0%   { opacity: 0; transform: scale(1.02); }
  2%   { opacity: 1; }
  12%  { opacity: 1; }
  15%  { opacity: 0; transform: scale(1.09); }
  100% { opacity: 0; transform: scale(1.09); }
}
.lv-shade {
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(5, 22, 17, .18) 0%, rgba(5, 22, 17, .45) 55%, rgba(5, 22, 17, .86) 100%);
}
.lv-top { position: absolute; top: 24px; left: 26px; z-index: 2; display: flex; align-items: center; gap: 10px; }
.lv-badge { background: var(--yellow); color: #2b1f00; font-size: 10.5px; font-weight: 700; letter-spacing: .1em; padding: 4px 8px; }
.lv-sub { color: rgba(255, 255, 255, .85); font-size: 11.5px; letter-spacing: .12em; }
.lv-content { position: absolute; left: 40px; right: 40px; bottom: 74px; z-index: 2; color: #fff; }
.lv-content h2 { font-size: 36px; line-height: 1.28; font-weight: 600; letter-spacing: .01em; }
.lv-content p { margin-top: 14px; font-size: 13px; color: rgba(255, 255, 255, .78); letter-spacing: .04em; }
.lv-foot { position: absolute; left: 40px; bottom: 28px; z-index: 2; font-size: 11.5px; color: rgba(255, 255, 255, .55); }

.login-form { padding: 56px 48px; display: flex; flex-direction: column; justify-content: center; background: #fff; position: relative; z-index: 2; }
.lf-head { margin-bottom: 26px; }
.lf-tag {
  display: inline-block; font-size: 10.5px; letter-spacing: .14em; color: var(--primary);
  border-left: 3px solid var(--primary); padding-left: 8px; margin-bottom: 12px;
}
.lf-head h1 { font-size: 21px; line-height: 1.45; font-weight: 600; color: var(--ink); }
.lf-head p { font-size: 12px; color: var(--ink-muted); margin-top: 8px; line-height: 1.7; }
.login-form .btn { height: 46px; margin-top: 6px; }
.lf-foot { margin-top: 22px; padding-top: 16px; border-top: 1px solid var(--hairline); font-size: 11.5px; color: var(--ink-subtle); line-height: 1.8; }

.login-form > * { animation: lfUp .62s cubic-bezier(.22, 1, .36, 1) both; }
.login-form > *:nth-child(1) { animation-delay: .06s; }
.login-form > *:nth-child(2) { animation-delay: .12s; }
.login-form > *:nth-child(3) { animation-delay: .18s; }
.login-form > *:nth-child(4) { animation-delay: .24s; }
.login-form > *:nth-child(5) { animation-delay: .30s; }
@keyframes lfUp { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }

@media (max-width: 820px) {
  .login-shell { grid-template-columns: 1fr; height: auto; max-height: none; }
  .login-visual { height: 200px; }
  .lv-content { left: 24px; right: 24px; bottom: 22px; }
  .lv-content h2 { font-size: 25px; }
  .lv-foot { display: none; }
  .login-form { padding: 28px 22px 32px; }
}
@media (prefers-reduced-motion: reduce) {
  .lv-slide { animation: none; }
  .lv-slide:first-child { opacity: 1; }
  .login-form > * { animation: none; }
}

/* 登录页全屏 */
.login-page { padding: 0; }
.login-shell {
  width: 100%; height: 100vh; max-height: none;
  grid-template-columns: 1.18fr .82fr;
  box-shadow: none; border-top: 0;
}
.login-form { padding: 0 clamp(40px, 7vw, 110px); align-items: flex-start; }
.login-form > * { width: 100%; max-width: 400px; }
.lf-head h1 { font-size: 24px; }
.lv-content { left: clamp(40px, 5vw, 72px); bottom: 90px; }
.lv-content h2 { font-size: clamp(34px, 3.4vw, 48px); }
.lv-top { top: 32px; left: clamp(40px, 5vw, 72px); }
.lv-foot { left: clamp(40px, 5vw, 72px); bottom: 40px; }
@media (max-width: 900px) {
  .login-shell { height: auto; min-height: 100vh; grid-template-columns: 1fr; }
  .login-visual { height: 240px; }
  .login-form { padding: 30px 22px 40px; align-items: stretch; }
}

/* 登录页移动端 */
@media (max-width: 900px) {
  .login-form { justify-content: flex-start; padding-top: 26px; }
  .login-visual { height: 230px; }
  .lv-top { top: 14px; left: 18px; }
  .lv-content { left: 18px; right: 18px; bottom: 16px; }
  .lv-content h2 { font-size: 23px; line-height: 1.25; }
  .lv-content p { margin-top: 6px; font-size: 11px; }
  .lv-foot { display: none; }
  .lf-head { margin-bottom: 18px; }
  .lf-head h1 { font-size: 21px; }
}

/* 登录页演示账号下拉 */
.demo-picker { margin-bottom: 18px; padding: 12px 14px; background: #fff8e1; border-left: 3px solid var(--yellow); }
.demo-picker label { display: block; font-size: 11.5px; font-weight: 600; color: var(--yellow-dark); letter-spacing: .06em; margin-bottom: 6px; }
.demo-picker select {
  width: 100%; height: 36px; border: 1px solid #e6cf8a; background: #fff;
  padding: 0 10px; font-size: 13px; outline: none;
}
.demo-picker select:focus { border-color: var(--primary); box-shadow: inset 0 -2px 0 var(--primary); }
.demo-picker .demo-hint { font-size: 10.5px; color: #a08334; margin-top: 6px; line-height: 1.6; }

/* 后台内容区铺满，避免右侧大片空白 */
html, body { width: 100%; }
.layout { width: 100%; }
.main { flex: 1 1 auto; width: 0; min-width: 0; }
.content { width: 100%; max-width: none; flex: 1 1 auto; box-sizing: border-box; }
.grid-2 { grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr); }
.kpi-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
@media (max-width: 1080px) {
  .kpi-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-2 { grid-template-columns: minmax(0, 1fr); }
}

/* 登录页移动端：去掉图片与表单之间的空白 */
@media (max-width: 900px) {
  .login-shell { display: flex; flex-direction: column; grid-template-rows: none; align-content: stretch; min-height: 100vh; }
  .login-visual { height: 230px; flex: none; }
  .login-form { flex: 1 1 auto; justify-content: flex-start; }
}

/* 宽屏时内容居中，窄屏铺满，避免单侧大片空白 */
.content { max-width: 1560px; margin: 0 auto; }

/* 窄屏改为纵向布局时，主区恢复自动宽度 */
@media (max-width: 760px) {
  .main { width: auto; flex: 1 1 auto; }
  .content { margin: 0; max-width: none; }
}