:root {
  --teal: #0d9488;
  --teal-dark: #0f766e;
  --teal-light: #ccfbf1;
  --ink: #1f2937;
  --ink-soft: #6b7280;
  --bg: #fafaf9;
  --card: #ffffff;
  --border: #e7e5e4;
  --danger: #dc2626;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 1px 2px rgba(0,0,0,.04), 0 8px 24px rgba(0,0,0,.06);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.5;
}

a { color: var(--teal-dark); text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 920px;
  margin: 0 auto;
  padding: 24px 20px 8px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 20px;
  color: var(--ink);
}

.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--teal), #14b8a6);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  flex-shrink: 0;
}

.site-nav a {
  margin-left: 20px;
  color: var(--ink-soft);
  font-size: 14px;
  font-weight: 500;
}

.hero {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
  padding: 28px 20px 8px;
}

.hero h1 {
  font-size: clamp(28px, 4vw, 40px);
  margin: 0 0 10px;
  letter-spacing: -0.02em;
}

.hero p {
  color: var(--ink-soft);
  font-size: 17px;
  margin: 0;
}

.tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin: 28px auto 0;
  max-width: 920px;
  padding: 0 20px;
}

.tab-btn {
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--ink-soft);
  padding: 10px 20px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all .15s ease;
}

.tab-btn:hover { border-color: var(--teal); color: var(--teal-dark); }

.tab-btn.active {
  background: var(--ink);
  border-color: var(--ink);
  color: white;
}

.panel { display: none; }
.panel.active { display: block; }

main {
  max-width: 920px;
  margin: 0 auto;
  padding: 20px 20px 60px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px;
  margin-top: 20px;
}

.dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: all .15s ease;
  background: linear-gradient(180deg, #fff, #fcfcfb);
}

.dropzone:hover, .dropzone.drag-over {
  border-color: var(--teal);
  background: var(--teal-light);
}

.dropzone-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 14px;
  color: var(--teal);
}

.dropzone h3 {
  margin: 0 0 6px;
  font-size: 18px;
}

.dropzone p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.dropzone input[type="file"] { display: none; }

.options-row {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  align-items: flex-start;
  margin-top: 24px;
}

.option-group { flex: 1; min-width: 220px; }

.option-group label.group-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-soft);
  text-transform: uppercase;
  letter-spacing: .04em;
  margin-bottom: 10px;
}

.preset-choices {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.preset-choice {
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  background: white;
  transition: all .15s ease;
  flex: 1;
  text-align: center;
  min-width: 100px;
}

.preset-choice:hover { border-color: var(--teal); }
.preset-choice.selected {
  border-color: var(--teal);
  background: var(--teal-light);
  color: var(--teal-dark);
}

.preset-choice small { display: block; font-weight: 400; color: var(--ink-soft); margin-top: 2px; }
.preset-choice small[data-role="size-estimate"] { font-weight: 700; color: var(--teal-dark); margin-top: 4px; min-height: 15px; }

select, input[type="range"] {
  width: 100%;
  padding: 10px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  background: white;
  color: var(--ink);
}

.file-list {
  margin-top: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.file-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: #fdfdfc;
}

.file-row .file-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--teal-light);
  color: var(--teal-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.file-row .file-info { flex: 1; min-width: 0; }
.file-row .file-name {
  font-weight: 600;
  font-size: 14px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.file-row .file-meta { font-size: 13px; color: var(--ink-soft); margin-top: 2px; }
.file-row .file-meta .saved { color: var(--teal-dark); font-weight: 600; }

.progress-bar {
  height: 6px;
  border-radius: 3px;
  background: var(--border);
  overflow: hidden;
  margin-top: 6px;
}
.progress-bar-fill {
  height: 100%;
  background: var(--teal);
  width: 0%;
  transition: width .2s ease;
}

.file-row .file-action {
  flex-shrink: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: none;
  border-radius: var(--radius-sm);
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all .15s ease;
}

.btn-primary { background: var(--teal); color: white; }
.btn-primary:hover { background: var(--teal-dark); }
.btn-primary:disabled { background: var(--border); color: var(--ink-soft); cursor: not-allowed; }

.btn-ghost { background: transparent; color: var(--ink-soft); border: 1px solid var(--border); }
.btn-ghost:hover { border-color: var(--ink-soft); color: var(--ink); }

.actions-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 20px;
  flex-wrap: wrap;
  gap: 12px;
}

.summary-banner {
  display: none;
  margin-top: 20px;
  padding: 16px 20px;
  border-radius: var(--radius-sm);
  background: var(--teal-light);
  color: var(--teal-dark);
  font-weight: 600;
  font-size: 15px;
}
.summary-banner.show { display: block; }

.error-banner {
  display: none;
  margin-top: 16px;
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  background: #fef2f2;
  color: var(--danger);
  font-size: 14px;
  font-weight: 500;
}
.error-banner.show { display: block; }

.trust-note {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--ink-soft);
  margin-top: 16px;
}
.trust-note svg { width: 16px; height: 16px; color: var(--teal); flex-shrink: 0; }

.ad-slot {
  max-width: 920px;
  margin: 24px auto;
  padding: 0 20px;
  text-align: center;
  min-height: 0;
}

.site-footer {
  max-width: 920px;
  margin: 40px auto 0;
  padding: 24px 20px 40px;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--ink-soft);
  font-size: 13px;
}

.site-footer a { margin: 0 10px; color: var(--ink-soft); }
.site-footer a:hover { color: var(--teal-dark); }

.announce-banner {
  background: linear-gradient(90deg, #fff3cd, #ffe9a8);
  border-bottom: 1px solid #f0d78a;
  padding: 10px 20px;
  text-align: center;
  font-size: 14px;
  color: #5c4200;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}
.announce-banner strong { font-weight: 700; }

.btn-donate {
  background: #ffc439;
  color: #1a1a1a;
  padding: 7px 16px;
  font-size: 13px;
}
.btn-donate:hover { background: #f0b429; }

.page-content {
  max-width: 680px;
  margin: 0 auto;
  padding: 40px 20px 80px;
}
.page-content h1 { font-size: 28px; }
.page-content h2 { font-size: 20px; margin-top: 32px; }
.page-content p, .page-content li { color: var(--ink-soft); font-size: 15px; }

@media (max-width: 600px) {
  .card { padding: 20px; }
  .dropzone { padding: 32px 16px; }
  .options-row { flex-direction: column; gap: 16px; }
}