:root {
  --ink: #1f2430;
  --muted: #697386;
  --brand: #4b2c88;
  --brand-strong: #32196d;
  --line: rgba(66, 54, 110, 0.16);
  --panel: rgba(255, 255, 255, 0.88);
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  background:
    linear-gradient(90deg, rgba(255,255,255,0.96), rgba(255,255,255,0.72)),
    url("/static/background.png") center right / cover no-repeat fixed;
}

.shell {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  padding: 48px min(8vw, 96px);
}

.panel {
  width: min(760px, 100%);
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--panel);
  box-shadow: 0 24px 70px rgba(54, 42, 96, 0.18);
  backdrop-filter: blur(10px);
}

header {
  display: flex;
  align-items: center;
  gap: 22px;
  margin-bottom: 26px;
}

header img {
  width: min(310px, 45%);
  height: auto;
  object-fit: contain;
}

header p {
  margin: 0 0 6px;
  color: var(--brand);
  font-size: 14px;
  font-weight: 700;
}

h1 {
  margin: 0;
  font-size: 30px;
  line-height: 1.2;
  letter-spacing: 0;
}

.upload-card {
  display: grid;
  gap: 18px;
  margin-top: 22px;
}

label {
  display: grid;
  gap: 9px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

input[type="file"] {
  width: 100%;
  padding: 15px;
  border: 1px dashed rgba(75, 44, 136, 0.34);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.86);
  color: var(--ink);
  font-size: 15px;
}

button,
.download {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--brand), var(--brand-strong));
  color: #fff;
  cursor: pointer;
  font-size: 16px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 12px 24px rgba(75, 44, 136, 0.22);
}

button:hover,
.download:hover {
  filter: brightness(1.05);
}

.download {
  margin-top: 18px;
  padding: 0 22px;
}

.notice {
  margin: 16px 0;
  padding: 13px 15px;
  border-radius: 12px;
  font-weight: 700;
}

.success {
  background: #ecf8f0;
  color: #247245;
  border: 1px solid #bde7ca;
}

.error {
  background: #fff1f1;
  color: #9e2b2b;
  border: 1px solid #f0b9b9;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 18px 0 4px;
}

.stats div {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.78);
}

.stats span {
  display: block;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.stats strong {
  display: block;
  margin-top: 7px;
  color: var(--brand-strong);
  font-size: 26px;
}

@media (max-width: 680px) {
  .shell {
    padding: 22px;
  }

  .panel {
    padding: 24px;
    border-radius: 14px;
  }

  header {
    align-items: flex-start;
    flex-direction: column;
  }

  header img {
    width: min(280px, 100%);
  }

  h1 {
    font-size: 25px;
  }

  .stats {
    grid-template-columns: 1fr;
  }
}