:root {
  --bg: #f5f6f8;
  --card: #ffffff;
  --border: #e2e5ea;
  --ink: #1f2430;
  --muted: #6b7280;
  --accent: #4f46e5;
  --accent-d: #4338ca;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --aa-hydrophobic: #dbeafe;
  --aa-polar: #dcfce7;
  --aa-acidic: #fee2e2;
  --aa-basic: #ede9fe;
  --aa-special: #fef9c3;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--ink);
  font-size: 14px;
}

/* topbar */
.topbar {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 16px;
  padding: 12px 20px;
  background: linear-gradient(120deg, #4f46e5, #7c3aed);
  color: #fff;
  box-shadow: 0 1px 6px rgba(0,0,0,.15);
}
.topbar h1 { margin: 0; font-size: 18px; font-weight: 650; }
.topbar .status { font-size: 12.5px; opacity: .9; }
.topbar-btn {
  margin-left: auto; border: 1px solid rgba(255,255,255,.5);
  background: rgba(255,255,255,.12); color: #fff;
  padding: 6px 12px; border-radius: 7px; cursor: pointer; font-size: 13px;
}
.topbar-btn:hover { background: rgba(255,255,255,.25); }

/* loader */
.loader { max-width: 880px; margin: 28px auto; padding: 0 18px; }
.loader-hero h2 { margin: 0 0 6px; font-size: 22px; }
.loader-hero p { margin: 0 0 18px; color: var(--muted); line-height: 1.5; }
.loader-row { display: flex; gap: 12px; align-items: flex-end; margin-bottom: 14px; }
.loader-row.two { flex-wrap: wrap; }
.loader-field { display: flex; flex-direction: column; gap: 5px; font-size: 12.5px; color: var(--muted); }
.loader-field.grow { flex: 1; min-width: 240px; }
.loader-field input[type=text], .loader-field textarea {
  padding: 9px 11px; border: 1px solid var(--border); border-radius: 8px;
  font-size: 14px; font-family: var(--mono); background: var(--card);
}
.loader-field textarea { resize: vertical; }
.loader-field input[type=file] { font-size: 12.5px; }
.loader-hint { font-size: 12px; color: var(--muted); }
.loader-samples { margin: 6px 0 16px; }
.sample-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 10px; margin-top: 8px; }
.sample-card {
  text-align: left; border: 1px solid var(--border); background: var(--card);
  border-radius: 9px; padding: 10px 12px; cursor: pointer; display: flex; flex-direction: column; gap: 4px;
}
.sample-card:hover { border-color: var(--accent); box-shadow: 0 2px 8px rgba(79,70,229,.12); }
.sample-card .acc { font-family: var(--mono); font-weight: 700; color: var(--accent); margin-right: 6px; }
.sample-card .name { font-weight: 600; }
.sample-card .desc { font-size: 12px; color: var(--muted); }
.loader-divider { text-align: center; color: var(--muted); margin: 8px 0 16px; position: relative; }
.loader-divider::before { content: ""; position: absolute; top: 50%; left: 0; right: 0; height: 1px; background: var(--border); }
.loader-divider span { background: var(--bg); padding: 0 12px; position: relative; font-size: 12px; }
.loader-error { color: #b91c1c; font-size: 13px; }

.btn {
  border: 1px solid var(--border); background: var(--card); color: var(--ink);
  padding: 9px 14px; border-radius: 8px; cursor: pointer; font-size: 13.5px; font-weight: 550;
}
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { background: var(--accent-d); }

.url-help { margin-top: 18px; font-size: 13px; }
.url-help summary { cursor: pointer; color: var(--accent); }
.url-help-body { padding: 10px 4px; color: var(--muted); line-height: 1.5; }

/* app */
#app { max-width: 1100px; margin: 22px auto; padding: 0 18px; }
.detail { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 18px; }
.header-card h2 { margin: 0 0 2px; font-size: 18px; font-family: var(--mono); }
.header-card .pname { color: var(--muted); margin-bottom: 10px; }
.metrics { display: flex; flex-wrap: wrap; gap: 16px; margin-bottom: 8px; }
.metric { display: flex; flex-direction: column; }
.metric .label { font-size: 11px; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); }
.metric .value { font-weight: 650; }
.cov-summary { margin: 8px 0; padding: 8px 12px; background: #f8f7ff; border: 1px solid #e7e4fb; border-radius: 8px; }
.cov-summary .warn, .warn { color: #b45309; }
.header-card-actions { display: flex; gap: 10px; margin-top: 12px; }

/* tabs */
.tabs { display: flex; gap: 4px; margin: 16px 0 14px; border-bottom: 1px solid var(--border); flex-wrap: wrap; }
.tab {
  border: none; background: none; padding: 9px 14px; cursor: pointer;
  font-size: 13.5px; color: var(--muted); border-bottom: 2px solid transparent; font-weight: 550;
}
.tab:hover { color: var(--ink); }
.tab.active { color: var(--accent); border-bottom-color: var(--accent); }

/* controls */
.cov-controls { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; margin-bottom: 10px; }
.cov-controls label { display: flex; align-items: center; gap: 6px; font-size: 13px; }
.cov-controls input[type=number], .cov-controls select {
  padding: 5px 8px; border: 1px solid var(--border); border-radius: 6px; font-size: 13px;
}
.cov-controls input[type=number] { width: 64px; }
.cov-hint { color: var(--muted); font-size: 12.5px; }
.overlay-picker { display: flex; flex-wrap: wrap; gap: 6px 16px; margin: 4px 0 12px; }
.ov-check { font-size: 12.5px; display: flex; align-items: center; gap: 5px; color: var(--ink); }

/* legend */
.legend { display: flex; flex-wrap: wrap; gap: 14px; margin: 8px 0 12px; font-size: 12px; color: var(--muted); align-items: center; }
.legend-item { display: flex; align-items: center; gap: 6px; }
.legend-square { display: inline-flex; align-items: center; justify-content: center; width: 18px; height: 18px; border-radius: 4px; font-family: var(--mono); font-size: 11px; color: #333; }
.legend-square.uncovered { background: #f0f0f0; border: 1px solid #ddd; }
.depth-chip { display: inline-flex; align-items: center; justify-content: center; min-width: 22px; height: 18px; border-radius: 4px; font-size: 11px; color: #5a2a00; padding: 0 4px; }
.depth-label { font-size: 11px; }

/* sequence view */
.sequence-area { font-family: var(--mono); font-size: 13px; line-height: 1.2; overflow-x: auto; padding: 6px 0; }
.seq-group { margin-bottom: 8px; }
.seq-line { white-space: nowrap; display: flex; align-items: center; }
.seq-pos { display: inline-block; width: 46px; text-align: right; padding-right: 10px; color: var(--muted); font-size: 11px; }
.seq-pos.end { width: auto; padding-right: 0; padding-left: 10px; }
.aa {
  display: inline-flex; align-items: center; justify-content: center;
  width: 17px; height: 20px; border-radius: 3px;
}
.aa.tick { box-shadow: inset -1px 0 0 rgba(0,0,0,.12); }
.aa.cov.uncovered { background: #f3f4f6; color: #9aa1ad; }
.aa.cov.covered { color: #5a2a00; }
.aa.cov.covered.dark { color: #fff; }

/* property overlay tracks */
.track-line { white-space: nowrap; display: flex; align-items: center; height: 11px; margin-top: 1px; }
.track-label { display: inline-block; width: 46px; text-align: right; padding-right: 10px; color: var(--muted); font-size: 9px; overflow: hidden; }
.track-cell { display: inline-flex; width: 17px; height: 9px; border-radius: 1px; }
.track-cell.empty-cell { background: transparent; }

/* 3D */
.viewer3d { position: relative; width: 100%; height: 520px; border: 1px solid var(--border); border-radius: 10px; margin: 6px 0; background: #fff; overflow: hidden; }
.dual3d-labels { display: flex; gap: 8px; margin-top: 6px; }
.panel-label { flex: 1; display: flex; align-items: center; gap: 8px; font-size: 12.5px; font-weight: 600; color: var(--ink); padding: 2px 4px; }
.mini-legend { display: inline-flex; gap: 0; border: 1px solid var(--border); border-radius: 3px; overflow: hidden; }
.mini-legend i { width: 14px; height: 12px; display: inline-block; }

/* tables */
.digest-table-wrap { overflow-x: auto; margin-top: 8px; }
.digest-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.digest-table th, .digest-table td { padding: 6px 9px; border-bottom: 1px solid var(--border); text-align: right; }
.digest-table th.seq, .digest-table td.seq { text-align: left; font-family: var(--mono); }
.digest-table th { color: var(--muted); font-weight: 600; font-size: 12px; }
.digest-section-title { font-weight: 650; margin: 16px 0 4px; }
.unmatched-row { background: #fff7ed; }
.unmatched-list { columns: 3; font-family: var(--mono); font-size: 12.5px; color: #9a3412; padding-left: 18px; }
.up { color: #b91c1c; } .down { color: #1d4ed8; } .muted { color: var(--muted); }
.analysis-intro, .analysis-table .bars { font-size: 12.5px; }
.bar-row { display: flex; align-items: center; gap: 6px; }
.bar-tag { font-size: 10px; width: 26px; color: var(--muted); }
.bar { flex: 1; height: 8px; background: #f1f2f4; border-radius: 4px; overflow: hidden; min-width: 90px; }
.bar > div { height: 100%; }

/* peptide editor */
.pep-editor { max-width: 560px; }
.pep-editor textarea { width: 100%; font-family: var(--mono); font-size: 13px; padding: 9px; border: 1px solid var(--border); border-radius: 8px; resize: vertical; }
.pep-editor-actions { display: flex; gap: 10px; margin-top: 10px; }

.computing { color: var(--muted); display: inline-flex; align-items: center; gap: 6px; }
.spinner { width: 12px; height: 12px; border: 2px solid var(--border); border-top-color: var(--accent); border-radius: 50%; display: inline-block; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.empty, .site-disclaimer { color: var(--muted); font-size: 12.5px; }
.site-disclaimer { margin: 8px 0; }
.digest-error { color: #b91c1c; }