/* =============================================================
   1. Tokens
   ============================================================= */
:root {
  --bg: #F7F7F5;
  --surface: #FFFFFF;
  --surface-2: #F0F0EE;
  --ink: #151A23;
  --ink-soft: #565D6B;
  --border: #E3E3DF;
  --accent: #38B6A7;
  --accent-ink: #FFFFFF;
  --success: #2E9E5B;
  --warn-bg: #FFF4E5;
  --warn-ink: #8A5A00;
  --sans: "Manrope", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, monospace;

  --radius-s: 8px;
  --radius-m: 14px;
  --radius-l: 22px;
  --gutter: clamp(1.1rem, 3vw, 2rem);

  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #10131A;
    --surface: #161A23;
    --surface-2: #1D222D;
    --ink: #F2F3F5;
    --ink-soft: #A0A7B4;
    --border: #2A3040;
    --accent: #4FD9C8;
    --accent-ink: #0B1013;
    --success: #4ADE80;
    --warn-bg: #2E2410;
    --warn-ink: #E8B95C;
  }
}

/* =============================================================
   2. Reset & base
   ============================================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; }
html { -webkit-text-size-adjust: 100%; tab-size: 2; scroll-behavior: smooth; }
body {
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: clip;
  overscroll-behavior-y: none;
}
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; cursor: pointer; border: 0; background: none; }
a { color: inherit; text-decoration: none; }
input, select { font: inherit; color: inherit; }
p { text-wrap: pretty; }
h1, h2, h3 { text-wrap: balance; line-height: 1.15; letter-spacing: -0.01em; font-weight: 800; }
::selection { background: var(--accent); color: var(--accent-ink); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

/* =============================================================
   3. Utilities
   ============================================================= */
.container { max-width: 900px; margin-inline: auto; padding-inline: var(--gutter); }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
.is-hidden { display: none !important; }

.skip-link {
  position: fixed; top: -100px; left: 1rem;
  padding: .6rem 1rem; background: var(--ink); color: var(--bg);
  z-index: 9999; border-radius: 8px; font-weight: 600;
  transition: top .2s var(--ease-out);
}
.skip-link:focus { top: 1rem; }

/* =============================================================
   4. Typography
   ============================================================= */
h1 { font-size: clamp(1.9rem, 4.5vw, 2.9rem); }
h2 { font-size: clamp(1.35rem, 2.6vw, 1.7rem); margin-top: 2.6rem; margin-bottom: .9rem; }
.subtitle { font-size: clamp(1rem, 1.6vw, 1.15rem); color: var(--ink-soft); margin-top: .7rem; max-width: 46ch; }

/* =============================================================
   5. Components
   ============================================================= */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: .5rem; padding: .85rem 1.4rem; border-radius: var(--radius-s);
  font-weight: 700; font-size: .95rem; transition: transform .15s var(--ease-out), opacity .15s;
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover { opacity: .9; }
.btn-secondary { background: var(--surface-2); color: var(--ink); border: 1px solid var(--border); }
.btn-secondary:hover { background: var(--border); }
.btn-ghost { background: transparent; color: var(--ink); border: 1px dashed var(--border); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-small { padding: .5rem .85rem; font-size: .82rem; }

.field-group { margin-bottom: 0; }
.field-label { display: block; font-size: .82rem; font-weight: 700; color: var(--ink-soft); margin-bottom: .4rem; text-transform: uppercase; letter-spacing: .03em; }

.seg-control { display: flex; gap: .4rem; background: var(--surface-2); padding: .3rem; border-radius: var(--radius-s); }
.seg-btn { flex: 1; padding: .6rem .8rem; border-radius: calc(var(--radius-s) - 3px); font-weight: 700; font-size: .85rem; color: var(--ink-soft); white-space: nowrap; transition: background .15s, color .15s; }
.seg-btn.is-active { background: var(--surface); color: var(--ink); box-shadow: 0 1px 3px rgba(0,0,0,.08); }

input[type="range"] { width: 100%; accent-color: var(--accent); }
input[type="number"] {
  width: 100%; padding: .65rem .8rem; border-radius: var(--radius-s);
  border: 1px solid var(--border); background: var(--surface); color: var(--ink); font-size: .95rem;
}

/* Dropzone */
.dropzone {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: .4rem; text-align: center; padding: clamp(1.8rem, 5vw, 2.6rem) 1.2rem;
  border: 2px dashed var(--border); border-radius: var(--radius-m);
  background: var(--surface-2); cursor: pointer; color: var(--ink-soft);
  transition: border-color .15s, background .15s;
}
.dropzone:hover, .dropzone.is-dragover { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 6%, var(--surface-2)); color: var(--ink); }
.dropzone svg { color: var(--accent); }
.dropzone p { margin: 0; }
.dropzone strong { color: var(--ink); }
.dropzone-hint { font-size: .82rem; }

.options-row {
  display: grid; grid-template-columns: 1fr; gap: 1rem;
  margin-top: 1.3rem; align-items: end;
}
@media (min-width: 620px) { .options-row { grid-template-columns: 1fr 1fr; } }

/* File list */
.file-list { margin-top: 1.4rem; display: flex; flex-direction: column; gap: .8rem; }
.file-row {
  border: 1px solid var(--border); border-radius: var(--radius-m); padding: .9rem 1rem;
  background: var(--surface); display: grid; grid-template-columns: 52px 1fr auto; gap: .9rem; align-items: center;
}
.file-thumb { width: 52px; height: 52px; border-radius: var(--radius-s); object-fit: cover; background: var(--surface-2); }
.file-info { min-width: 0; }
.file-name { font-weight: 700; font-size: .9rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.file-meta { font-size: .82rem; color: var(--ink-soft); font-family: var(--mono); }
.file-meta .saved { color: var(--success); font-weight: 700; }
.file-progress { height: 4px; border-radius: 2px; background: var(--surface-2); margin-top: .5rem; overflow: hidden; }
.file-progress-bar { height: 100%; width: 0%; background: var(--accent); transition: width .2s var(--ease-out); }
.file-actions { display: flex; align-items: center; gap: .5rem; }
.file-error { color: #C0392B; font-size: .82rem; }

.batch-actions { display: flex; gap: .7rem; margin-top: 1.4rem; flex-wrap: wrap; }

.privacy-badge { margin-top: 1.4rem; font-size: .85rem; color: var(--ink-soft); text-align: center; }
.limit-note { margin-top: .4rem; font-size: .78rem; color: var(--ink-soft); text-align: center; }

/* =============================================================
   6. Sections
   ============================================================= */
.site-header { padding-block: 1.1rem; border-bottom: 1px solid var(--border); }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.brand { display: flex; align-items: center; gap: .5rem; font-weight: 800; font-size: 1.15rem; color: var(--ink); }
.brand-mark { color: var(--accent); display: inline-flex; }
.header-tag { font-size: .85rem; color: var(--ink-soft); display: none; }
@media (min-width: 540px) { .header-tag { display: inline; } }

.hero { padding-block: clamp(2rem, 5vw, 3.2rem) 1.4rem; }

.tool-section { padding-block: .5rem 1.5rem; }
.tool-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-l);
  padding: clamp(1.1rem, 3vw, 1.8rem); box-shadow: 0 10px 40px -20px rgba(0,0,0,.18);
}

.ad-slot {
  min-height: 90px; border: 1px dashed var(--border); border-radius: var(--radius-s);
  display: flex; align-items: center; justify-content: center; color: var(--ink-soft);
  font-size: .8rem; margin-block: 1.8rem; letter-spacing: .05em; text-transform: uppercase;
}

.content-section { padding-block: 1rem 3rem; }
.content-section p { color: var(--ink-soft); max-width: 68ch; margin-bottom: 1rem; }

.steps { list-style: none; display: grid; gap: 1.1rem; margin-block: 1.2rem 2rem; padding: 0; }
@media (min-width: 720px) { .steps { grid-template-columns: repeat(3, 1fr); } }
.steps li { display: flex; gap: .8rem; align-items: flex-start; }
.step-num {
  flex-shrink: 0; width: 30px; height: 30px; border-radius: 50%; background: var(--accent); color: var(--accent-ink);
  display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: .9rem;
}
.steps strong { display: block; margin-bottom: .2rem; }
.steps p { font-size: .9rem; margin: 0; }

details {
  border: 1px solid var(--border); border-radius: var(--radius-s); padding: .9rem 1.1rem;
  margin-bottom: .6rem; background: var(--surface);
}
details summary { font-weight: 700; cursor: pointer; }
details p { margin-top: .6rem; margin-bottom: 0; }

.site-footer { border-top: 1px solid var(--border); padding-block: 1.5rem; margin-top: 2rem; }
.footer-inner { display: flex; flex-wrap: wrap; gap: .8rem 1.5rem; align-items: center; justify-content: space-between; color: var(--ink-soft); font-size: .85rem; }
.footer-inner nav { display: flex; gap: 1.2rem; }
.footer-inner a:hover { color: var(--accent); }

/* =============================================================
   7. Effects
   ============================================================= */
.seg-btn, .btn, .dropzone { transition: all .15s var(--ease-out); }

/* =============================================================
   8. Responsive
   ============================================================= */
@media (max-width: 480px) {
  .file-row { grid-template-columns: 44px 1fr; }
  .file-actions { grid-column: 1 / -1; justify-content: flex-end; }
}

/* =============================================================
   9. Reduced motion
   ============================================================= */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn, .seg-btn, .dropzone, .file-progress-bar { transition: none; }
}