:root {
  --bg: #f5f7fb;
  --card: #fff;
  --ink: #1c2433;
  --muted: #6b7688;
  --line: #e3e8f0;
  --brand: #2563eb;
  --brand-dark: #1d4ed8;
  --danger: #dc2626;
  --radius: 14px;
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 15px/1.6 -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
}
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { width: min(1080px, calc(100% - 32px)); margin: 0 auto; }
.muted { color: var(--muted); }
.small { font-size: 13px; }
code { background: #eef1f6; padding: 1px 6px; border-radius: 6px; }

.site-header { background: var(--card); border-bottom: 1px solid var(--line); }
.nav-row { display: flex; align-items: center; gap: 20px; height: 64px; }
.brand { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 18px; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand-dot { width: 12px; height: 12px; border-radius: 50%; background: linear-gradient(135deg, var(--brand), #22d3ee); }
.nav { display: flex; gap: 4px; flex: 1; flex-wrap: wrap; }
.nav a { padding: 8px 12px; border-radius: 8px; color: var(--muted); font-weight: 500; }
.nav a:hover { background: #f0f3f9; color: var(--ink); text-decoration: none; }
.nav a.on { background: #e8f0fe; color: var(--brand-dark); }
.nav-auth { display: flex; align-items: center; gap: 10px; }
.who { color: var(--muted); font-size: 13px; }

.btn { display: inline-flex; align-items: center; gap: 6px; border: 1px solid transparent; border-radius: 10px; padding: 9px 16px; font-size: 14px; font-weight: 600; cursor: pointer; background: #eef1f6; color: var(--ink); }
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); }
.btn-ghost { background: transparent; border-color: var(--line); color: var(--ink); }
.btn-danger { background: #fee2e2; color: var(--danger); }
.btn-lg { padding: 13px 26px; font-size: 16px; }
.btn-mini { padding: 5px 10px; font-size: 13px; }
.inline { display: inline; }

.hero { padding: 44px 0 24px; text-align: center; }
.hero h1 { font-size: 34px; margin: 0 0 8px; }
.lead { color: var(--muted); max-width: 640px; margin: 0 auto 24px; }
.uploader { display: flex; flex-direction: column; align-items: center; gap: 14px; }
.drop { display: flex; flex-direction: column; align-items: center; gap: 6px; width: min(560px, 100%); padding: 34px 24px; border: 2px dashed #c4cede; border-radius: var(--radius); background: var(--card); cursor: pointer; transition: border-color .15s, background .15s; }
.drop:hover, .drop.over { border-color: var(--brand); background: #f2f7ff; }
.drop input[type=file] { display: none; }
.drop-icon { font-size: 26px; color: var(--brand); }
.drop-text { font-weight: 600; }
.drop-hint { color: var(--muted); font-size: 13px; }
.drop-locked { cursor: default; border-style: solid; }

.stats { list-style: none; display: flex; justify-content: center; gap: 40px; padding: 22px 0 0; margin: 26px 0 0; border-top: 1px solid var(--line); }
.stats b { display: block; font-size: 22px; }
.stats span { color: var(--muted); font-size: 13px; }
.stats-4 { gap: 28px; }

.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; margin: 26px 0; }
.cards article { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; }
.cards h3 { margin: 0 0 6px; font-size: 16px; }
.cards p { margin: 0; color: var(--muted); font-size: 14px; }

.notice { background: #fff8e6; border: 1px solid #f2d488; border-radius: var(--radius); padding: 16px 18px; margin: 22px 0; }
.notice h2 { margin: 0 0 6px; font-size: 16px; }
.notice p { margin: 0; color: #7a5b12; }

.panel { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; margin: 24px 0; }
.panel-narrow { max-width: 460px; margin: 40px auto; }
.panel-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; }
.panel h1 { margin: 0 0 16px; font-size: 22px; }
.panel h2 { margin: 24px 0 10px; font-size: 17px; }
.center { text-align: center; }
.body-text { white-space: pre-wrap; }

.stack { display: flex; flex-direction: column; gap: 14px; }
.stack label, .panel label { display: flex; flex-direction: column; gap: 6px; font-size: 14px; color: var(--muted); }
label.check { flex-direction: row; align-items: center; }
input[type=email], input[type=password], input[type=number], input[type=search], input[type=text], textarea {
  font: inherit; padding: 10px 12px; border: 1px solid var(--line); border-radius: 10px; background: #fbfcfe; color: var(--ink); width: 100%;
}
input:focus, textarea:focus { outline: 2px solid #bfdbfe; border-color: var(--brand); }

.file-card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; margin: 26px 0; }
.file-head { display: flex; align-items: center; gap: 16px; }
.file-icon { font-size: 30px; width: 60px; height: 60px; display: grid; place-items: center; background: #eef2ff; border-radius: 14px; }
.file-name { margin: 0; font-size: 20px; word-break: break-all; }
.file-actions { display: flex; gap: 12px; flex-wrap: wrap; margin: 22px 0 14px; }
.share-line { display: flex; align-items: center; gap: 10px; }
.share-line label { color: var(--muted); white-space: nowrap; }
.share-line input { font-family: ui-monospace, Menlo, monospace; }

.ok-banner, .err-banner { padding: 10px 14px; border-radius: 10px; margin: 0 0 18px; }
.ok-banner { background: #dcfce7; color: #14532d; }
.err-banner { background: #fee2e2; color: #7f1d1d; }
.empty { color: var(--muted); }

table.list { width: 100%; border-collapse: collapse; margin-top: 10px; font-size: 14px; }
table.list th { text-align: left; color: var(--muted); font-weight: 600; padding: 8px 10px; border-bottom: 1px solid var(--line); white-space: nowrap; }
table.list td { padding: 10px; border-bottom: 1px solid #f0f3f8; vertical-align: middle; }
.fname { word-break: break-all; font-weight: 500; }
.row-actions { white-space: nowrap; display: flex; gap: 6px; }

.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 8px; border-bottom: 1px solid var(--line); padding-bottom: 10px; }
.tabs a { padding: 7px 12px; border-radius: 8px; color: var(--muted); }
.tabs a.on { background: #e8f0fe; color: var(--brand-dark); font-weight: 600; }
.searchbar { display: flex; gap: 8px; margin: 8px 0 14px; }
.searchbar input { max-width: 340px; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px; }
.ad-slot { margin: 22px 0; min-height: 1px; }

.site-footer { border-top: 1px solid var(--line); background: var(--card); margin-top: 40px; padding: 26px 0 18px; }
.foot-row { display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; }
.foot-links { display: flex; gap: 18px; align-items: center; }
.foot-links a { color: var(--muted); }
.copy { color: var(--muted); font-size: 13px; margin-top: 18px; }

@media (max-width: 720px) {
  .nav-row { height: auto; flex-wrap: wrap; padding: 12px 0; }
  .hero h1 { font-size: 26px; }
  .stats { flex-wrap: wrap; gap: 20px; }
  table.list { display: block; overflow-x: auto; }
}