:root {
  --bg: #f4f7fb;
  --surface: #ffffff;
  --text: #152033;
  --muted: #5b6b84;
  --primary: #1f6feb;
  --primary-hover: #1558c0;
  --border: #d9e2ef;
  --success-bg: #ecfdf3;
  --success-border: #abefc6;
  --success-text: #067647;
  --error-bg: #fef3f2;
  --error-border: #fecdca;
  --error-text: #b42318;
  --shadow: 0 18px 50px rgba(21, 32, 51, 0.08);
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  min-height: 100%;
}

body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(31, 111, 235, 0.12), transparent 28%),
    radial-gradient(circle at top right, rgba(16, 185, 129, 0.1), transparent 24%),
    var(--bg);
  line-height: 1.6;
}

a {
  color: var(--primary);
}

.page {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
  padding: 40px 0 64px;
}

.hero {
  margin-bottom: 24px;
}

.badge {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  padding: 0 12px;
  border-radius: 999px;
  background: rgba(31, 111, 235, 0.1);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
}

h1 {
  margin: 14px 0 8px;
  font-size: clamp(28px, 5vw, 40px);
  line-height: 1.2;
}

.lead {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
  max-width: 640px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px;
}

.form-grid {
  display: grid;
  gap: 18px;
}

label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
}

.help {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.file-input {
  width: 100%;
  min-height: 52px;
  padding: 12px 14px;
  border: 1px dashed var(--border);
  border-radius: 14px;
  background: #f8fbff;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 8px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  min-width: 120px;
  padding: 0 18px;
  border: 0;
  border-radius: 12px;
  background: var(--primary);
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 160ms ease, transform 160ms ease;
}

.button:hover {
  background: var(--primary-hover);
}

.button:focus-visible,
.file-input:focus-visible,
.link-input:focus-visible {
  outline: 3px solid rgba(31, 111, 235, 0.28);
  outline-offset: 2px;
}

.button.secondary {
  background: #eef4ff;
  color: var(--primary);
}

.button.secondary:hover {
  background: #dfeaff;
}

.alert {
  margin-bottom: 18px;
  padding: 14px 16px;
  border-radius: 14px;
  border: 1px solid transparent;
}

.alert.error {
  background: var(--error-bg);
  border-color: var(--error-border);
  color: var(--error-text);
}

.alert.success {
  background: var(--success-bg);
  border-color: var(--success-border);
  color: var(--success-text);
}

.result-grid {
  display: grid;
  gap: 16px;
}

.meta {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 14px;
}

.link-row {
  display: grid;
  gap: 12px;
}

.link-input {
  width: 100%;
  min-height: 48px;
  padding: 0 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #f8fbff;
  color: var(--text);
  font-size: 14px;
}

.footer {
  margin-top: 18px;
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 640px) {
  .page {
    width: min(100% - 24px, 920px);
    padding-top: 24px;
  }

  .card {
    padding: 20px;
  }

  .button,
  .button.secondary {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}