:root {
  --bg: #f4f6fb;
  --card: #ffffff;
  --ink: #1f2733;
  --muted: #7b848f;
  --accent: #4f6ef7;
  --accent-dark: #3a55d6;
  --border: #e5e9f2;
  --ok: #22b573;
  --danger: #e5484d;
  --shadow: 0 10px 30px rgba(31, 39, 51, .08);
  --radius: 16px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 900px; margin: 0 auto; padding: 0 20px; }

/* ===== Header ===== */
.topbar { padding: 34px 0 8px; }
.brand { display: flex; align-items: center; gap: 12px; }
.logo {
  display: inline-flex; width: 40px; height: 40px; align-items: center; justify-content: center;
  background: var(--accent); color: #fff; border-radius: 12px; font-size: 20px;
}
.brand h1 { font-size: 24px; margin: 0; letter-spacing: .5px; }
.tagline { color: var(--muted); margin: 10px 0 0 52px; font-size: 14px; }

/* ===== Dropzone ===== */
.dropzone {
  margin-top: 24px;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  background: var(--card);
  padding: 56px 20px;
  text-align: center;
  cursor: pointer;
  transition: border-color .2s, background .2s, transform .15s;
  box-shadow: var(--shadow);
  outline: none;
}
.dropzone:hover, .dropzone:focus-visible, .dropzone.dragover {
  border-color: var(--accent);
  background: #f7f9ff;
}
.dropzone.dragover { transform: scale(1.01); }
.dz-icon { font-size: 34px; color: var(--accent); }
.dz-title { margin: 12px 0 4px; font-size: 17px; font-weight: 600; }
.dz-sub { margin: 0; color: var(--muted); font-size: 14px; }

/* ===== Panel ===== */
.panel {
  margin-top: 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
}
.controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
}
.field label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 8px; }
.field select, .field input[type="number"] {
  width: 100%; padding: 9px 10px; font-size: 15px;
  border: 1px solid var(--border); border-radius: 10px; background: #fff; color: var(--ink);
}
.field input[type="color"] {
  width: 100%; height: 40px; border: 1px solid var(--border); border-radius: 10px;
  padding: 4px; background: #fff; cursor: pointer;
}
.range-field input[type="range"] { width: 100%; accent-color: var(--accent); }
.range-field label { color: var(--ink); font-weight: 600; }
#qualityVal { color: var(--accent); font-weight: 700; }
.hint { font-size: 12px; color: var(--muted); margin: 8px 0 0; min-height: 1em; }

.actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 20px; flex-wrap: wrap; }

/* ===== Buttons ===== */
.btn {
  border: none; border-radius: 10px; padding: 11px 18px; font-size: 14px; cursor: pointer;
  transition: background .2s, transform .1s, opacity .2s;
}
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--accent); color: #fff; font-weight: 600; }
.btn.primary:hover { background: var(--accent-dark); }
.btn.ghost { background: #eef1f8; color: var(--ink); }
.btn.ghost:hover { background: #e3e8f5; }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn.small { padding: 8px 14px; font-size: 13px; }

/* ===== Results ===== */
.results { margin-top: 24px; display: grid; gap: 14px; }
.result-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 16px; display: flex; gap: 16px; align-items: flex-start;
}
.preview {
  flex: 0 0 auto; width: 150px; max-width: 40%;
  border-radius: 12px; overflow: hidden; background: #f0f2f7; border: 1px solid var(--border);
}
.preview img { width: 100%; display: block; }
.meta { flex: 1 1 auto; min-width: 0; font-size: 14px; }
.meta .name { font-weight: 600; margin: 0 0 6px; word-break: break-all; }
.sizes { display: flex; gap: 14px; flex-wrap: wrap; color: var(--muted); margin: 0 0 10px; }
.sizes .delta { color: var(--ok); font-weight: 600; }
.meta .actions { margin: 8px 0 0; justify-content: flex-start; }

.empty {
  text-align: center; color: var(--muted); padding: 40px 0; font-size: 14px;
}
.toast {
  position: fixed; left: 50%; bottom: 28px; transform: translateX(-50%);
  background: var(--ink); color: #fff; padding: 11px 18px; border-radius: 10px;
  font-size: 14px; box-shadow: var(--shadow); opacity: 0; pointer-events: none;
  transition: opacity .25s, transform .25s;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(-6px); }

.batch-bar { text-align: right; margin-top: 16px; }

.footer { color: var(--muted); font-size: 13px; text-align: center; padding: 30px 20px 40px; }

.spinner {
  display: inline-block; width: 16px; height: 16px; border: 2px solid rgba(255,255,255,.4);
  border-top-color: #fff; border-radius: 50%; animation: spin .7s linear infinite; vertical-align: -3px;
}
.spinner.dark { border-color: rgba(31,39,51,.2); border-top-color: var(--ink); }
@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 600px) {
  .brand h1 { font-size: 20px; }
  .tagline { margin-left: 0; }
  .result-card { flex-direction: column; }
  .preview { width: 100%; max-width: 100%; }
}