/* =========================================================
   Image → AVIF Converter — stylesheet
   Design tokens live in :root. Everything else is built from them.
   ========================================================= */

:root {
  /* Color */
  --color-bg:        #ffffff;
  --color-surface:   #f6f8fb;
  --color-surface-2: #eef2f7;
  --color-border:    #e2e8f0;
  --color-text:      #101828;
  --color-muted:     #5b6472;
  --color-primary:      #1d4ed8;
  --color-primary-dark: #1739a6;
  --color-primary-light:#e8efff;
  --color-accent:    #0aa6a6; /* signals "converted / smaller" state */
  --color-success:   #0f9d58;
  --color-success-bg:#e8f7ee;
  --color-error:     #c0362c;
  --color-error-bg:  #fdecea;

  /* Type */
  --font-display: -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-body:    -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono:    ui-monospace, "SFMono-Regular", "JetBrains Mono", "Cascadia Mono", Menlo, Consolas, monospace;

  /* Scale */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 2px rgba(16, 24, 40, 0.06);
  --shadow-md: 0 8px 24px rgba(16, 24, 40, 0.08);
  --shadow-lg: 0 20px 48px rgba(16, 24, 40, 0.12);
  --container: 1120px;
  --header-h: 68px;

  --transition: 180ms ease;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; }
button { font-family: inherit; }
ul { padding-left: 1.2em; }
h1, h2, h3, h4 { font-family: var(--font-display); line-height: 1.15; margin: 0 0 0.5em; letter-spacing: -0.01em; }
p { margin: 0 0 1em; color: var(--color-text); }
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* Visible focus for all interactive elements */
a:focus-visible,
button:focus-visible,
input:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: 4px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -48px;
  background: var(--color-primary);
  color: #fff;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  z-index: 200;
  transition: top var(--transition);
  text-decoration: none;
  font-weight: 600;
}
.skip-link:focus { top: 12px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.9);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-h);
  display: flex;
  align-items: center;
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 700;
  font-size: 1.15rem;
}
.brand-mark {
  width: 34px; height: 34px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  display: flex; align-items: center; justify-content: center;
  color: #fff;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.72rem;
  flex-shrink: 0;
}
.brand-name .brand-ext { color: var(--color-accent); }

.main-nav ul {
  list-style: none;
  display: flex;
  gap: 4px;
  margin: 0;
  padding: 0;
}
.main-nav a {
  display: inline-block;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-weight: 500;
  color: var(--color-muted);
  font-size: 0.95rem;
  transition: background var(--transition), color var(--transition);
}
.main-nav a:hover { background: var(--color-surface); color: var(--color-text); }
.main-nav a[aria-current="page"] {
  color: var(--color-primary);
  background: var(--color-primary-light);
}

.nav-toggle {
  display: none;
  border: 1px solid var(--color-border);
  background: #fff;
  border-radius: var(--radius-sm);
  width: 42px; height: 42px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}
.nav-toggle .bar {
  display: block;
  width: 20px; height: 2px;
  background: var(--color-text);
  position: relative;
  transition: background var(--transition);
}
.nav-toggle .bar::before,
.nav-toggle .bar::after {
  content: "";
  position: absolute;
  left: 0;
  width: 20px; height: 2px;
  background: var(--color-text);
  transition: transform var(--transition);
}
.nav-toggle .bar::before { top: -6px; }
.nav-toggle .bar::after { top: 6px; }
.nav-toggle[aria-expanded="true"] .bar { background: transparent; }
.nav-toggle[aria-expanded="true"] .bar::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .bar::after { transform: translateY(-6px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  padding: 64px 0 40px;
  background:
    radial-gradient(600px 300px at 85% -10%, var(--color-primary-light), transparent 70%);
}
.hero-inner { max-width: 760px; }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-primary);
  background: var(--color-primary-light);
  border-radius: 999px;
  padding: 6px 12px;
  margin-bottom: 18px;
}
.hero h1 {
  font-size: clamp(2rem, 4.4vw, 3rem);
  font-weight: 700;
}
.hero .lede {
  font-size: 1.125rem;
  color: var(--color-muted);
  max-width: 62ch;
}
.trust-note {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.92rem;
  color: var(--color-accent);
  font-weight: 600;
  margin-top: 8px;
}
.trust-note svg { flex-shrink: 0; }

/* ---------- Converter ---------- */
.converter {
  padding: 8px 0 72px;
}
.converter-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(16px, 4vw, 32px);
  box-shadow: var(--shadow-sm);
}

/* Dropzone */
.dropzone {
  border: 2px dashed #b9c6dc;
  border-radius: var(--radius-md);
  background: #fff;
  padding: clamp(28px, 6vw, 56px) 20px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
}
.dropzone:hover { border-color: var(--color-primary); }
.dropzone.is-dragover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}
.dropzone-icon {
  width: 56px; height: 56px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: var(--color-primary-light);
  display: flex; align-items: center; justify-content: center;
  color: var(--color-primary);
}
.dropzone h2 { font-size: 1.2rem; margin-bottom: 6px; }
.dropzone .or { color: var(--color-muted); margin: 10px 0; font-size: 0.9rem; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.98rem;
  padding: 12px 22px;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-primary:disabled { background: #9db2e0; cursor: not-allowed; transform: none; }
.btn-outline {
  background: #fff;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}
.btn-outline:hover { background: var(--color-primary-light); }
.btn-ghost {
  background: transparent;
  color: var(--color-muted);
  border: 1px solid var(--color-border);
}
.btn-ghost:hover { background: var(--color-surface-2); color: var(--color-text); }
.btn-success { background: var(--color-success); color: #fff; }
.btn-success:hover { filter: brightness(0.94); }
.btn-block { width: 100%; }
.btn-lg { padding: 14px 28px; font-size: 1.02rem; }

.dropzone-meta {
  margin-top: 14px;
  font-size: 0.82rem;
  color: var(--color-muted);
}

/* Workspace shown once an image is loaded */
.workspace {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}
.panel {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
}
.panel h3 {
  font-size: 1.02rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.panel-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
@media (max-width: 720px) {
  .panel-grid { grid-template-columns: 1fr; }
}

.preview-frame {
  border-radius: var(--radius-sm);
  overflow: hidden;
  background:
    linear-gradient(45deg, #f0f2f5 25%, transparent 25%),
    linear-gradient(-45deg, #f0f2f5 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #f0f2f5 75%),
    linear-gradient(-45deg, transparent 75%, #f0f2f5 75%);
  background-size: 16px 16px;
  background-position: 0 0, 0 8px, 8px -8px, -8px 0;
  border: 1px solid var(--color-border);
  min-height: 160px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.preview-frame img { max-height: 320px; width: auto; margin: 0 auto; }

.file-stats {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 0.88rem;
}
.file-stats li {
  display: flex;
  justify-content: space-between;
  padding: 7px 0;
  border-bottom: 1px dashed var(--color-border);
  gap: 12px;
}
.file-stats li:last-child { border-bottom: none; }
.file-stats dt, .file-stats .label { color: var(--color-muted); font-family: var(--font-body); }
.file-stats .value { font-weight: 600; text-align: right; word-break: break-word; }

/* Settings */
.field { margin-bottom: 18px; }
.field:last-child { margin-bottom: 0; }
.field-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 6px;
}
.field-label .quality-value {
  font-family: var(--font-mono);
  color: var(--color-primary);
}
.field-help {
  font-size: 0.82rem;
  color: var(--color-muted);
  margin-top: 6px;
}
input[type="range"] {
  width: 100%;
  accent-color: var(--color-primary);
  height: 6px;
  cursor: pointer;
}
.checkbox-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
}
.checkbox-row input { width: 18px; height: 18px; accent-color: var(--color-primary); }

.resize-fields {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 12px;
}
.resize-fields .field { margin-bottom: 0; }
.resize-fields label {
  display: block;
  font-size: 0.82rem;
  color: var(--color-muted);
  margin-bottom: 4px;
}
.resize-fields input[type="number"] {
  width: 100%;
  padding: 9px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.92rem;
}
.aspect-row {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--color-muted);
  font-weight: 500;
}
.aspect-row input { accent-color: var(--color-primary); }
[hidden] { display: none !important; }

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* Progress / status */
.status-line {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  margin-top: 16px;
}
.spinner {
  width: 18px; height: 18px;
  border: 3px solid var(--color-primary-light);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.alert {
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 0.92rem;
  margin-top: 16px;
  display: flex;
  gap: 10px;
  align-items: flex-start;
}
.alert-error { background: var(--color-error-bg); color: var(--color-error); border: 1px solid #f3c9c5; }
.alert-success { background: var(--color-success-bg); color: var(--color-success); border: 1px solid #bfe8cf; }
.alert-info { background: var(--color-primary-light); color: var(--color-primary-dark); border: 1px solid #c7d7fb; }

/* Result / compression meter (signature element) */
.result-panel { border-color: var(--color-accent); }
.compression-meter {
  margin: 18px 0 6px;
}
.meter-track {
  position: relative;
  height: 34px;
  border-radius: 999px;
  background: var(--color-surface-2);
  overflow: hidden;
  border: 1px solid var(--color-border);
}
.meter-fill {
  position: absolute;
  inset: 0;
  width: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transform-origin: left center;
  transition: width 700ms cubic-bezier(.2,.8,.2,1);
  border-radius: 999px;
}
.meter-labels {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--color-muted);
  margin-top: 8px;
}
.meter-headline {
  font-family: var(--font-mono);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-accent);
}
.meter-headline small {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--color-muted);
}

/* Queue (multi-file) */
.queue { margin-top: 24px; display: grid; gap: 12px; }
.queue-item {
  display: grid;
  grid-template-columns: 56px 1fr auto;
  align-items: center;
  gap: 14px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
}
.queue-thumb {
  width: 56px; height: 56px;
  border-radius: 8px;
  object-fit: cover;
  background: var(--color-surface-2);
}
.queue-info { min-width: 0; }
.queue-name {
  font-weight: 600;
  font-size: 0.92rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.queue-meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-muted);
}
.queue-status {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}
.queue-status.pending { color: var(--color-muted); }
.queue-status.working { color: var(--color-primary); }
.queue-status.done { color: var(--color-success); }
.queue-status.failed { color: var(--color-error); }
.queue-actions { display: flex; gap: 8px; }
.queue-actions .btn { padding: 8px 12px; font-size: 0.85rem; }

/* ---------- Features / How it works ---------- */
.section { padding: 64px 0; }
.section-alt { background: var(--color-surface); }
.section-head { max-width: 620px; margin: 0 auto 40px; text-align: center; }
.section-head h2 { font-size: clamp(1.6rem, 3vw, 2.1rem); }
.section-head p { color: var(--color-muted); margin: 0; }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
@media (max-width: 960px) { .feature-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .feature-grid { grid-template-columns: 1fr; } }

.feature-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: transform var(--transition), box-shadow var(--transition);
}
.feature-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.feature-icon {
  width: 42px; height: 42px;
  border-radius: 10px;
  background: var(--color-primary-light);
  color: var(--color-primary);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 14px;
}
.feature-card h3 { font-size: 1.02rem; margin-bottom: 6px; }
.feature-card p { color: var(--color-muted); font-size: 0.92rem; margin: 0; }

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  counter-reset: step;
}
@media (max-width: 800px) { .steps { grid-template-columns: 1fr; } }
.step-card {
  position: relative;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 26px 22px;
}
.step-num {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--color-primary);
  background: var(--color-primary-light);
  display: inline-block;
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 12px;
  font-weight: 700;
}
.step-card h3 { font-size: 1.02rem; }
.step-card p { color: var(--color-muted); font-size: 0.92rem; margin: 0; }

/* ---------- Generic content pages ---------- */
.page-hero {
  padding: 56px 0 28px;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface);
}
.page-hero h1 { font-size: clamp(1.8rem, 3.4vw, 2.4rem); }
.page-hero p { color: var(--color-muted); max-width: 60ch; margin: 0; }

.prose { padding: 48px 0 72px; }
.prose .container { max-width: 820px; }
.prose h2 { font-size: 1.3rem; margin-top: 2em; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 1.05rem; margin-top: 1.5em; }
.prose ul { color: var(--color-text); }
.prose p, .prose li { color: var(--color-muted); }
.prose strong { color: var(--color-text); }
.callout {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  margin: 1.4em 0;
}
.callout p:last-child { margin-bottom: 0; }

.contact-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
}
.contact-email {
  display: inline-block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  text-decoration: none;
}
.contact-email:hover { background: #dbe6ff; }

/* About mission grid */
.mission-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 8px;
}
@media (max-width: 800px) { .mission-grid { grid-template-columns: 1fr; } }
.mission-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 22px;
}
.mission-card h3 { font-size: 1rem; }
.mission-card p { color: var(--color-muted); font-size: 0.92rem; margin: 0; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
  padding: 48px 0 28px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
}
@media (max-width: 800px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 480px) { .footer-grid { grid-template-columns: 1fr; } }
.footer-grid h4 {
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-muted);
  margin-bottom: 14px;
}
.footer-grid ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.footer-grid a { text-decoration: none; color: var(--color-text); font-size: 0.92rem; }
.footer-grid a:hover { color: var(--color-primary); }
.footer-about p { color: var(--color-muted); font-size: 0.9rem; max-width: 36ch; }
.footer-bottom {
  margin-top: 36px;
  padding-top: 20px;
  border-top: 1px solid var(--color-border);
  font-size: 0.82rem;
  color: var(--color-muted);
  text-align: center;
}

/* ---------- Mobile nav ---------- */
@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; }
  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0;
    background: #fff;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition);
  }
  .main-nav.is-open { max-height: 480px; }
  .main-nav ul { flex-direction: column; padding: 8px; gap: 2px; }
  .main-nav a { display: block; padding: 12px 14px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}