/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --primary: #4F46E5;
  --primary-dark: #4338CA;
  --bg: #F8FAFC;
  --bg-card: #FFFFFF;
  --text: #1E293B;
  --text-muted: #64748B;
  --border: #E2E8F0;
  --success: #10B981;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,.08), 0 4px 6px -2px rgba(0,0,0,.04);
}

html { font-size: 16px; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img { max-width: 100%; height: auto; display: block; }

.container {
  width: 100%;
  max-width: 880px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Header ===== */
.header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background: rgba(255,255,255,.92);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--primary);
  text-decoration: none;
  letter-spacing: -.5px;
}

.header nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: .875rem;
  transition: color .15s;
}

.header nav a:hover { color: var(--text); }

/* ===== Hero ===== */
.hero {
  text-align: center;
  padding: 48px 0 24px;
}

.hero h1 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -.75px;
  line-height: 1.2;
}

.hero-sub {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-top: 10px;
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== AdSense Placeholders ===== */
.ad-placeholder {
  background: var(--bg-card);
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 24px auto;
}

.ad-top {
  min-height: 90px;
  max-width: 728px;
}

.ad-bottom {
  min-height: 250px;
  max-width: 728px;
}

.ad-label {
  color: var(--text-muted);
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* ===== Tool Section ===== */
.tool-section {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
}

/* ===== Quality Toggle ===== */
.quality-toggle {
  margin-bottom: 20px;
}

.quality-label {
  font-size: .85rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .5px;
  margin-bottom: 10px;
}

.quality-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.quality-card {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  border: 2px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  transition: all .15s;
  background: var(--bg);
}

.quality-card:hover {
  border-color: #A5B4FC;
}

.quality-card input[type="radio"] {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

.quality-card-active {
  border-color: var(--primary);
  background: #EEF2FF;
}

.quality-card-title {
  font-size: .95rem;
  font-weight: 700;
  color: var(--text);
}

.quality-card-desc {
  font-size: .75rem;
  color: var(--text-muted);
  line-height: 1.4;
}

@media (max-width: 480px) {
  .quality-options { grid-template-columns: 1fr; }
}

/* ===== Drop Zone ===== */
.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color .2s, background .2s;
  position: relative;
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--primary);
  background: #EEF2FF;
}

.drop-icon {
  color: var(--primary);
  margin-bottom: 12px;
}

.drop-text {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.drop-text-small {
  color: var(--text-muted);
  font-size: .85rem;
  margin: 8px 0;
}

.btn-file {
  display: inline-block;
  margin: 8px 0;
  cursor: pointer;
}

.btn-file input[type="file"] {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  border-radius: 8px;
  font-size: .95rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all .15s;
  text-decoration: none;
  position: relative;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--border);
}

/* ===== Progress ===== */
.progress-section {
  margin-top: 24px;
  padding: 16px 0;
}

.progress-bar-track {
  height: 8px;
  background: var(--border);
  border-radius: 99px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--primary), #818CF8);
  border-radius: 99px;
  transition: width .3s ease;
}

.progress-text {
  margin-top: 8px;
  font-size: .85rem;
  color: var(--text-muted);
  text-align: center;
}

/* ===== Result ===== */
.result-section {
  margin-top: 24px;
}

.result-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.result-card h3 {
  font-size: .85rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .5px;
  margin-bottom: 8px;
}

.result-image-wrap {
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #fff;
}

.result-image-wrap img {
  width: 100%;
  display: block;
}

.result-checkerboard {
  background-image:
    linear-gradient(45deg, #ddd 25%, transparent 25%),
    linear-gradient(-45deg, #ddd 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #ddd 75%),
    linear-gradient(-45deg, transparent 75%, #ddd 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0;
}

.result-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-top: 20px;
  flex-wrap: wrap;
}

/* ===== Privacy Banner ===== */
.privacy-banner {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: #EEF2FF;
  border: 1px solid #C7D2FE;
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 24px 0;
  color: var(--text);
  font-size: .9rem;
  line-height: 1.5;
}

.privacy-banner svg {
  flex-shrink: 0;
  color: var(--primary);
  margin-top: 2px;
}

/* ===== Footer ===== */
.footer {
  margin-top: auto;
  border-top: 1px solid var(--border);
  padding: 24px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: .85rem;
}

.footer a {
  color: var(--primary);
  text-decoration: none;
}

.footer a:hover { text-decoration: underline; }

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .hero h1 { font-size: 1.5rem; }
  .hero { padding: 32px 0 16px; }
  .tool-section { padding: 20px; }
  .drop-zone { padding: 32px 16px; }
  .result-grid { grid-template-columns: 1fr; }
  .ad-top { min-height: 50px; }
  .ad-bottom { min-height: 100px; }
}