:root {
  --bg: #f4f6f8;
  --surface: #ffffff;
  --surface-alt: #f8fafb;
  --border: #e2e8ee;
  --text: #17212b;
  --text-muted: #64748b;
  --accent: #0f6e63;
  --accent-dark: #0b5750;
  --accent-soft: #e6f3f1;
  --danger: #c0392b;
  --danger-soft: #fbeceb;
  --shadow: 0 1px 2px rgba(16, 24, 32, 0.04), 0 8px 24px rgba(16, 24, 32, 0.06);
  --radius: 12px;
  font-size: 16px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
}

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

.header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 18px 32px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.header img.logo {
  height: 42px;
  width: auto;
  object-fit: contain;
}

.header .titles {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.header .titles .lab-name {
  font-weight: 650;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
}

.header .titles .lab-sub {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.header .spacer { flex: 1; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: 999px;
  border: 1px solid transparent;
  background: var(--accent);
  color: white;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.05s ease, box-shadow 0.15s ease;
}

.btn:hover { background: var(--accent-dark); }
.btn:active { transform: translateY(1px); }
.btn:disabled { background: #b7c2c9; cursor: not-allowed; }

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover { background: var(--surface-alt); color: var(--text); }

.container {
  max-width: 980px;
  margin: 0 auto;
  padding: 28px 24px 120px;
}

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

/* ---------- login page ---------- */
.login-wrap {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background:
    radial-gradient(circle at 15% 20%, rgba(15, 110, 99, 0.10), transparent 45%),
    radial-gradient(circle at 85% 80%, rgba(15, 110, 99, 0.08), transparent 45%),
    var(--bg);
}

.login-card {
  width: 100%;
  max-width: 400px;
  padding: 40px 36px 32px;
  text-align: center;
}

.login-card img.logo {
  height: 64px;
  margin-bottom: 18px;
  object-fit: contain;
}

.login-card h1 {
  font-size: 1.25rem;
  margin: 0 0 2px;
  letter-spacing: -0.01em;
}

.login-card .sub {
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 28px;
}

.field {
  text-align: left;
  margin-bottom: 16px;
}

.field label {
  display: block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.field input {
  width: 100%;
  padding: 11px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface-alt);
  font-size: 0.95rem;
  color: var(--text);
}

.field input:focus {
  outline: none;
  border-color: var(--accent);
  background: white;
}

.login-card .btn {
  width: 100%;
  justify-content: center;
  padding: 12px;
  margin-top: 8px;
  font-size: 0.95rem;
}

.error-box {
  background: var(--danger-soft);
  color: var(--danger);
  padding: 10px 14px;
  border-radius: 8px;
  font-size: 0.85rem;
  margin-bottom: 18px;
  text-align: left;
}

.secure-note {
  margin-top: 22px;
  font-size: 0.75rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

/* ---------- browse page ---------- */
.summary-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin: 18px 2px 14px;
}

.summary-row h2 {
  font-size: 1.05rem;
  margin: 0;
}

.summary-row .muted {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.tree {
  padding: 10px 6px;
}

.node { margin: 0; }

.node > .row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 7px 12px;
  border-radius: 8px;
  cursor: pointer;
}

.node > .row:hover { background: var(--surface-alt); }

.node .caret {
  width: 14px;
  height: 14px;
  color: var(--text-muted);
  transition: transform 0.12s ease;
  flex-shrink: 0;
}
.node.collapsed > .row .caret { transform: rotate(-90deg); }

.node .icon { flex-shrink: 0; color: var(--text-muted); }

.node .name {
  flex: 1;
  font-size: 0.9rem;
  overflow-wrap: anywhere;
}

.node.dir > .row .name { font-weight: 600; }

.node .size {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

.node > .children {
  margin-left: 26px;
  border-left: 1px dashed var(--border);
  padding-left: 12px;
}

.node.collapsed > .children { display: none; }

input[type="checkbox"] {
  accent-color: var(--accent);
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.md5-panel {
  margin-top: 16px;
  padding: 16px 20px;
}

.md5-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.md5-title {
  font-weight: 650;
  font-size: 0.92rem;
  margin-bottom: 4px;
}

.md5-hint {
  font-size: 0.8rem;
  color: var(--text-muted);
  max-width: 520px;
}

.md5-hint code {
  background: var(--surface-alt);
  padding: 1px 5px;
  border-radius: 4px;
  font-size: 0.78rem;
}

.md5-value-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
}

.md5-value {
  background: var(--accent-soft);
  color: var(--accent-dark);
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 0.82rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  letter-spacing: 0.02em;
}

.selection-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--surface);
  border-top: 1px solid var(--border);
  box-shadow: 0 -4px 20px rgba(16,24,32,0.06);
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 18px;
  z-index: 20;
}

.selection-bar .info {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.selection-bar .info strong { color: var(--text); }

.selection-bar .spacer { flex: 1; }

.progress-wrap {
  display: none;
  flex-direction: column;
  gap: 6px;
  min-width: 220px;
}

.progress-track {
  height: 8px;
  border-radius: 999px;
  background: var(--border);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 0.2s ease;
}

.progress-label {
  font-size: 0.76rem;
  color: var(--text-muted);
}

@media (max-width: 640px) {
  .header { padding: 14px 16px; }
  .container { padding: 18px 12px 140px; }
  .selection-bar { flex-wrap: wrap; padding: 12px 16px; }
  .progress-wrap { min-width: 100%; order: 3; }
}