/* ── Tokens ─────────────────────────────────────────── */
:root {
  --bg: #f4f6fb;
  --surface: #ffffff;
  --border: #e2e6ee;
  --text: #1a1e2c;
  --text-soft: #5f6980;
  --accent: #4f46e5;
  --accent-hover: #4338ca;
  --accent-bg: #eef2ff;
  --green: #16a34a;
  --green-bg: #dcfce7;
  --red: #dc2626;
  --red-bg: #fee2e2;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-lg: 0 4px 16px rgba(0,0,0,.08);
  --font: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  --transition: .18s ease;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1219;
    --surface: #1a1f2e;
    --border: #2a3042;
    --text: #e4e7ee;
    --text-soft: #8891a5;
    --accent: #818cf8;
    --accent-hover: #a5b4fc;
    --accent-bg: #1e1b4b;
    --green: #4ade80;
    --green-bg: #14532d;
    --red: #f87171;
    --red-bg: #7f1d1d;
    --shadow: 0 1px 3px rgba(0,0,0,.3);
    --shadow-lg: 0 4px 16px rgba(0,0,0,.4);
  }
}
:root[data-theme="dark"] {
  --bg: #0f1219;
  --surface: #1a1f2e;
  --border: #2a3042;
  --text: #e4e7ee;
  --text-soft: #8891a5;
  --accent: #818cf8;
  --accent-hover: #a5b4fc;
  --accent-bg: #1e1b4b;
  --green: #4ade80;
  --green-bg: #14532d;
  --red: #f87171;
  --red-bg: #7f1d1d;
  --shadow: 0 1px 3px rgba(0,0,0,.3);
  --shadow-lg: 0 4px 16px rgba(0,0,0,.4);
}

/* ── Reset & base ──────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}
[hidden] { display: none !important; }
.hidden { display: none !important; }

/* ── App shell ─────────────────────────────────────── */
.app {
  max-width: 680px;
  margin: 0 auto;
  padding: 0 16px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ── Topbar ────────────────────────────────────────── */
.topbar {
  padding: 28px 0 12px;
  text-align: center;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.brand-icon {
  font-size: 28px;
  line-height: 1;
}
.brand-name {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--text);
}
.brand-tag {
  margin-top: 6px;
  font-size: 13px;
  color: var(--text-soft);
}

/* ── Main ──────────────────────────────────────────── */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 16px 0 32px;
}

/* ── Dropzone ──────────────────────────────────────── */
.upload-section {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 280px;
}
.dropzone {
  width: 100%;
  border: 2.5px dashed var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
}
.dropzone:hover, .dropzone.drag {
  border-color: var(--accent);
  background: var(--accent-bg);
}
.dz-icon {
  color: var(--accent);
  margin-bottom: 14px;
}
.dz-label {
  font-size: 16px;
  font-weight: 500;
  color: var(--text);
}
.dz-link {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}
.dz-hint {
  margin-top: 8px;
  font-size: 12.5px;
  color: var(--text-soft);
}

/* ── File info ─────────────────────────────────────── */
.file-info {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  box-shadow: var(--shadow);
}
.fi-row {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.fi-thumb {
  width: 64px;
  height: 82px;
  object-fit: cover;
  border-radius: 6px;
  border: 1px solid var(--border);
  flex-shrink: 0;
}
.fi-meta { flex: 1; min-width: 0; }
.fi-name {
  font-size: 16px;
  font-weight: 600;
  word-break: break-word;
  margin-bottom: 6px;
}
.fi-chips { display: flex; gap: 8px; flex-wrap: wrap; }
.chip {
  font-size: 12px;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 100px;
  background: var(--accent-bg);
  color: var(--accent);
}

/* ── Controls ──────────────────────────────────────── */
.controls {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.ctrl-heading {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-soft);
  margin-bottom: 12px;
}

/* Target size */
.ctrl-sub {
  font-size: 13px;
  color: var(--text-soft);
  line-height: 1.5;
  margin: -6px 0 14px;
}
.target-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}
.target-input-wrap {
  position: relative;
  display: inline-flex;
  align-items: center;
}
.target-input {
  width: 160px;
  font-size: 28px;
  font-weight: 700;
  padding: 10px 52px 10px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  outline: none;
}
.target-input:focus { border-color: var(--accent); }
.target-unit {
  position: absolute;
  right: 14px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-soft);
  pointer-events: none;
}
.target-quick { display: flex; gap: 8px; flex-wrap: wrap; }
.qbtn {
  font-size: 13px;
  font-weight: 600;
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}
.qbtn:hover { border-color: var(--accent); background: var(--accent-bg); }
.target-hint {
  font-size: 12.5px;
  color: var(--text-soft);
  line-height: 1.5;
  margin: 12px 0 0;
}

/* Automatic Low / Medium / High */
.ctrl-auto { margin-top: 26px; padding-top: 22px; border-top: 1px solid var(--border); }
.auto-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}
.autobtn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 14px 10px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  transition: border-color .12s, background .12s;
}
.autobtn:hover { border-color: var(--accent); background: var(--accent-bg); }
.autobtn:disabled { opacity: .5; cursor: default; }
.ab-name { font-size: 15px; font-weight: 700; }
.ab-desc { font-size: 11.5px; color: var(--text-soft); }

/* Options that apply to both modes */
.ctrl-options { margin-top: 22px; padding-top: 16px; border-top: 1px solid var(--border); }
.ctrl-options em { font-style: normal; color: var(--text-soft); }

/* Presets */
.preset-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.preset {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 12px 6px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: transparent;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
  font-family: inherit;
  color: var(--text);
}
.preset:hover { border-color: var(--accent); background: var(--accent-bg); }
.preset.active {
  border-color: var(--accent);
  background: var(--accent-bg);
  box-shadow: 0 0 0 1px var(--accent);
}
.preset-name { font-size: 13px; font-weight: 600; }
.preset-desc { font-size: 11px; color: var(--text-soft); }

/* Sliders */
.ctrl-sliders { display: flex; flex-direction: column; gap: 16px; }
.slider-group { display: flex; flex-direction: column; gap: 4px; }
.slider-label {
  display: flex;
  justify-content: space-between;
  font-size: 13.5px;
  font-weight: 500;
}
.slider-val { color: var(--accent); font-weight: 600; font-variant-numeric: tabular-nums; }
.slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--border);
  outline: none;
  cursor: pointer;
}
.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--surface);
  box-shadow: 0 1px 4px rgba(0,0,0,.18);
  cursor: pointer;
}
.slider::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--surface);
  box-shadow: 0 1px 4px rgba(0,0,0,.18);
  cursor: pointer;
}
.slider-range {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--text-soft);
}
.check-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  cursor: pointer;
  color: var(--text);
}
.check-label input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--accent);
  cursor: pointer;
}

/* Estimate */
.est-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  text-align: center;
}
.est-item {
  background: var(--bg);
  border-radius: var(--radius-sm);
  padding: 12px 8px;
}
.est-label {
  display: block;
  font-size: 11px;
  color: var(--text-soft);
  text-transform: uppercase;
  letter-spacing: .04em;
  margin-bottom: 4px;
}
.est-val {
  font-size: 17px;
  font-weight: 700;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

/* Action button row */
.ctrl-action { text-align: center; padding-top: 4px; }

/* ── Buttons ───────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  padding: 8px 18px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  transition: all var(--transition);
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-primary {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); color: #fff; }
.btn-ghost {
  background: transparent;
  border-color: transparent;
  color: var(--text-soft);
  padding: 6px 12px;
  font-size: 13px;
}
.btn-ghost:hover { color: var(--red); border-color: transparent; }
.btn-lg { padding: 12px 32px; font-size: 15px; border-radius: var(--radius); }

/* ── Progress ──────────────────────────────────────── */
.progress-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  box-shadow: var(--shadow);
  text-align: center;
}
.progress-track {
  width: 100%;
  height: 10px;
  background: var(--bg);
  border-radius: 5px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), #818cf8);
  border-radius: 5px;
  transition: width .3s ease;
}
.progress-label {
  margin-top: 10px;
  font-size: 13px;
  color: var(--text-soft);
  font-variant-numeric: tabular-nums;
}

/* ── Result ────────────────────────────────────────── */
.result-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow-lg);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}
.result-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--green);
}
.result-note {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-soft);
}
.result-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 10px;
}
.result-actions .btn-ghost { border: 1.5px solid var(--border); color: var(--text); }
.result-actions .btn-ghost:hover { border-color: var(--accent); background: var(--accent-bg); }
.result-stats {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}
.rs-item { text-align: center; }
.rs-label {
  display: block;
  font-size: 11px;
  color: var(--text-soft);
  text-transform: uppercase;
  letter-spacing: .04em;
  margin-bottom: 2px;
}
.rs-val { font-size: 18px; font-weight: 700; font-variant-numeric: tabular-nums; }
.rs-val.accent { color: var(--accent); }
.rs-arrow { font-size: 20px; color: var(--text-soft); }
.result-bar-wrap { width: 100%; max-width: 400px; }
.result-bar-track {
  width: 100%;
  height: 14px;
  background: var(--bg);
  border-radius: 7px;
  overflow: hidden;
}
.result-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--green), #4ade80);
  border-radius: 7px;
  transition: width .5s ease;
}
.result-bar-labels {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--text-soft);
  margin-top: 4px;
}

/* ── Toast ─────────────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--text);
  color: var(--bg);
  padding: 10px 22px;
  border-radius: 100px;
  font-size: 13.5px;
  font-weight: 500;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s, transform .25s;
  z-index: 900;
  white-space: nowrap;
  max-width: calc(100vw - 32px);
  overflow: hidden;
  text-overflow: ellipsis;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); pointer-events: auto; }
.toast.err { background: var(--red); color: #fff; }

/* ── Footer ────────────────────────────────────────── */
.footer {
  text-align: center;
  padding: 16px 0 24px;
  font-size: 12px;
  color: var(--text-soft);
}

/* ── Responsive ────────────────────────────────────── */
@media (max-width: 520px) {
  .preset-row { grid-template-columns: repeat(2, 1fr); }
  .est-row { grid-template-columns: 1fr; }
  .result-stats { flex-direction: column; gap: 10px; }
  .rs-arrow { display: none; }
  .fi-row { flex-direction: column; align-items: flex-start; }
  .fi-thumb { width: 48px; height: 62px; }
}