:root {
  --ai-primary:  #7c3aed;
  --ai-secondary:#2563eb;
  --ai-dark:     #0f172a;
  --ai-surface:  #ffffff;
  --ai-muted:    #64748b;
  --ai-border:   #e2e8f0;
  --ai-radius:   16px;
  --ai-ios:      #007aff;
  --ai-android:  #34a853;
}

/* ── HUB TOPBAR ───────────────────────────────── */
.hub-topbar {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  padding: 10px 0;
  border-bottom: 1px solid rgba(255,255,255,.08);
  font-size: .82rem;
  color: rgba(255,255,255,.6);
}
.hub-topbar a { color: rgba(255,255,255,.7); text-decoration: none; transition: color .2s; }
.hub-topbar a:hover { color: #fff; }

/* ── NAVBAR ───────────────────────────────────── */
.ai-brand-icon {
  width: 36px; height: 36px;
  border-radius: 10px;
  background: linear-gradient(145deg, var(--ai-primary), var(--ai-secondary));
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 1.1rem;
}
.ai-brand-icon-sm {
  width: 28px; height: 28px;
  border-radius: 8px;
  background: linear-gradient(145deg, var(--ai-primary), var(--ai-secondary));
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: .85rem;
}
.navbar { border-bottom: 1px solid var(--ai-border); }
.nav-link { color: var(--ai-muted) !important; font-weight: 500; font-size: .9rem; }
.nav-link:hover, .nav-link.active { color: var(--ai-primary) !important; }
.fw-800 { font-weight: 800; }
.fw-700 { font-weight: 700; }
.fw-600 { font-weight: 600; }

/* ── HERO ─────────────────────────────────────── */
.ai-hero {
  background: linear-gradient(135deg, #f5f3ff 0%, #eff6ff 50%, #f0fdf4 100%);
  padding: 64px 0 56px;
  border-bottom: 1px solid var(--ai-border);
}
.ai-hero-badge {
  display: inline-block;
  background: rgba(124,58,237,.1);
  color: var(--ai-primary);
  font-size: .78rem; font-weight: 700;
  padding: 5px 14px; border-radius: 20px;
  margin-bottom: 16px;
  border: 1px solid rgba(124,58,237,.15);
}
.ai-hero-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 900; letter-spacing: -.04em;
  color: var(--ai-dark); line-height: 1.1; margin-bottom: 16px;
}
.ai-hero-sub {
  font-size: 1.05rem; color: var(--ai-muted);
  max-width: 560px; margin: 0 auto; line-height: 1.6;
}
.ai-platform-pills { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin-top: 24px; }
.ai-platform-pill {
  display: flex; align-items: center; gap: 7px;
  padding: 7px 16px; border-radius: 20px;
  font-size: .82rem; font-weight: 700;
  border: 1px solid transparent;
}
.ai-platform-pill.ios    { background: rgba(0,122,255,.1);  color: var(--ai-ios);     border-color: rgba(0,122,255,.2); }
.ai-platform-pill.android{ background: rgba(52,168,83,.1);  color: var(--ai-android); border-color: rgba(52,168,83,.2); }
.ai-platform-pill.sizes  { background: rgba(124,58,237,.1); color: var(--ai-primary); border-color: rgba(124,58,237,.2); }

/* ── TOOL SECTION ─────────────────────────────── */
.ai-tool-section { padding: 56px 0; background: #f8fafc; }

.ai-tool-wrap {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 32px;
  align-items: start;
}
@media (max-width: 991px) { .ai-tool-wrap { grid-template-columns: 1fr; } }

/* ── UPLOAD PANEL ─────────────────────────────── */
.ai-upload-panel {
  background: #fff;
  border-radius: var(--ai-radius);
  border: 1px solid var(--ai-border);
  padding: 28px;
  box-shadow: 0 2px 16px rgba(0,0,0,.05);
}

.ai-dropzone {
  border: 2px dashed var(--ai-border);
  border-radius: 14px;
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: all .25s;
  background: #f8fafc;
  margin-bottom: 24px;
  position: relative;
}
.ai-dropzone:hover, .ai-dropzone.dragover {
  border-color: var(--ai-primary);
  background: #f5f3ff;
}
.ai-dropzone input[type="file"] {
  position: absolute; inset: 0; opacity: 0; cursor: pointer; width: 100%; height: 100%;
}
.ai-dropzone-icon { font-size: 3rem; color: #cbd5e1; margin-bottom: 12px; display: block; }
.ai-dropzone h5 { font-weight: 700; color: var(--ai-dark); margin-bottom: 6px; }
.ai-dropzone p  { font-size: .85rem; color: var(--ai-muted); margin: 0; }
.ai-dropzone .ai-browse-btn {
  display: inline-block; margin-top: 12px;
  padding: 8px 20px;
  background: linear-gradient(135deg, var(--ai-primary), var(--ai-secondary));
  color: #fff; border-radius: 8px;
  font-size: .85rem; font-weight: 700;
}

/* Preview state */
.ai-dropzone.has-file { padding: 16px; border-style: solid; border-color: var(--ai-primary); background: #fff; }
.ai-preview-img { max-width: 120px; max-height: 120px; border-radius: 16px; object-fit: cover; box-shadow: 0 4px 16px rgba(0,0,0,.12); }
.ai-preview-name { font-size: .85rem; font-weight: 600; color: var(--ai-dark); margin-top: 10px; }
.ai-preview-size { font-size: .78rem; color: var(--ai-muted); }
.ai-change-link  { font-size: .78rem; color: var(--ai-primary); cursor: pointer; text-decoration: underline; margin-top: 4px; display: block; }

/* Label */
.ai-label {
  display: block; font-size: .78rem; font-weight: 700;
  color: #374151; margin-bottom: 8px;
  text-transform: uppercase; letter-spacing: .05em;
}

/* Platform selector */
.ai-platform-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 10px; margin-bottom: 24px;
}
.ai-platform-btn {
  border: 2px solid var(--ai-border);
  border-radius: 12px; background: #f8fafc;
  padding: 14px 8px; text-align: center;
  cursor: pointer; transition: all .2s;
  color: var(--ai-muted);
}
.ai-platform-btn i  { font-size: 1.5rem; display: block; margin-bottom: 6px; }
.ai-platform-btn span { font-size: .8rem; font-weight: 700; display: block; }
.ai-platform-btn small { font-size: .68rem; color: var(--ai-muted); }
.ai-platform-btn:hover { border-color: var(--ai-primary); color: var(--ai-primary); background: #f5f3ff; }
.ai-platform-btn.active { border-color: var(--ai-primary); background: linear-gradient(135deg, #f5f3ff, #eff6ff); color: var(--ai-primary); box-shadow: 0 2px 8px rgba(124,58,237,.15); }
.ai-platform-btn.active.ios     { border-color: var(--ai-ios);     background: rgba(0,122,255,.06);  color: var(--ai-ios); }
.ai-platform-btn.active.android { border-color: var(--ai-android); background: rgba(52,168,83,.06);  color: var(--ai-android); }

/* Generate button */
.ai-generate-btn {
  width: 100%; padding: 14px;
  background: linear-gradient(135deg, var(--ai-primary), var(--ai-secondary));
  color: #fff; border: none; border-radius: 12px;
  font-size: 1rem; font-weight: 700; cursor: pointer;
  transition: all .25s; display: flex; align-items: center; justify-content: center; gap: 8px;
  box-shadow: 0 4px 16px rgba(124,58,237,.3);
}
.ai-generate-btn:hover:not(:disabled) { transform: translateY(-1px); box-shadow: 0 8px 24px rgba(124,58,237,.4); }
.ai-generate-btn:disabled { opacity: .6; cursor: not-allowed; transform: none; }
.ai-generate-btn .spinner { width: 18px; height: 18px; border: 2px solid rgba(255,255,255,.4); border-top-color: #fff; border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ── PREVIEW PANEL ────────────────────────────── */
.ai-preview-panel { position: sticky; top: 80px; }

.ai-sizes-card {
  background: #fff; border-radius: var(--ai-radius);
  border: 1px solid var(--ai-border); padding: 24px;
  box-shadow: 0 2px 16px rgba(0,0,0,.05); margin-bottom: 16px;
}
.ai-sizes-title {
  font-size: .82rem; font-weight: 700;
  color: var(--ai-muted); text-transform: uppercase;
  letter-spacing: .06em; margin-bottom: 16px;
}

.ai-platform-section { margin-bottom: 16px; }
.ai-platform-header {
  display: flex; align-items: center; gap: 8px;
  font-size: .8rem; font-weight: 700; margin-bottom: 8px;
}
.ai-platform-header.ios     { color: var(--ai-ios); }
.ai-platform-header.android { color: var(--ai-android); }

.ai-size-grid { display: flex; flex-wrap: wrap; gap: 6px; }
.ai-size-chip {
  font-size: .7rem; padding: 3px 8px; border-radius: 6px;
  font-weight: 600; background: #f1f5f9; color: var(--ai-muted);
}
.ai-size-chip.ios     { background: rgba(0,122,255,.08);  color: var(--ai-ios); }
.ai-size-chip.android { background: rgba(52,168,83,.08);  color: var(--ai-android); }

/* Tips card */
.ai-tips-card {
  background: #fff; border-radius: var(--ai-radius);
  border: 1px solid var(--ai-border); padding: 20px;
}
.ai-tips-title { font-size: .875rem; font-weight: 700; color: var(--ai-dark); margin-bottom: 12px; }
.ai-tips-list  { list-style: none; padding: 0; margin: 0; }
.ai-tips-list li {
  font-size: .82rem; color: var(--ai-muted);
  padding: 7px 0; border-bottom: 1px solid var(--ai-border); line-height: 1.5;
}
.ai-tips-list li:last-child { border-bottom: none; }

/* ── HOW IT WORKS ─────────────────────────────── */
.ai-how-section { padding: 80px 0; background: #fff; }
.ai-section-badge {
  display: inline-block; background: rgba(124,58,237,.08);
  color: var(--ai-primary); font-size: .78rem; font-weight: 700;
  padding: 5px 14px; border-radius: 20px; margin-bottom: 12px;
  border: 1px solid rgba(124,58,237,.12);
}
.ai-section-title { font-size: clamp(1.5rem, 3vw, 2rem); font-weight: 800; color: var(--ai-dark); letter-spacing: -.03em; }

.ai-step-card {
  text-align: center; padding: 36px 24px;
  border-radius: var(--ai-radius); border: 1px solid var(--ai-border);
  background: #fff; position: relative;
  transition: box-shadow .25s, transform .25s;
}
.ai-step-card:hover { box-shadow: 0 8px 32px rgba(0,0,0,.1); transform: translateY(-3px); }
.ai-step-num {
  position: absolute; top: -14px; left: 50%; transform: translateX(-50%);
  width: 28px; height: 28px; border-radius: 50%;
  background: linear-gradient(135deg, var(--ai-primary), var(--ai-secondary));
  color: #fff; font-size: .8rem; font-weight: 900;
  display: flex; align-items: center; justify-content: center;
}
.ai-step-icon {
  width: 60px; height: 60px; border-radius: 16px;
  background: linear-gradient(135deg, #f5f3ff, #eff6ff);
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 16px; font-size: 1.6rem; color: var(--ai-primary);
}
.ai-step-card h5 { font-weight: 700; color: var(--ai-dark); margin-bottom: 8px; }
.ai-step-card p  { font-size: .875rem; color: var(--ai-muted); margin: 0; }

/* ── SIZES TABLE ──────────────────────────────── */
.ai-sizes-section { padding: 80px 0; background: #f8fafc; }
.ai-sizes-table { border-radius: 14px; overflow: hidden; border: 1px solid var(--ai-border); }
.ai-sizes-table table { margin: 0; }
.ai-sizes-table thead th { background: #f8fafc; font-size: .75rem; font-weight: 700; color: var(--ai-muted); text-transform: uppercase; letter-spacing: .05em; border-bottom: 1px solid var(--ai-border); padding: 12px 16px; }
.ai-sizes-table tbody td { font-size: .875rem; padding: 10px 16px; border-color: var(--ai-border); }

/* ── CTA ──────────────────────────────────────── */
.ai-cta-section {
  padding: 80px 0;
  background: linear-gradient(135deg, var(--ai-primary), var(--ai-secondary));
  color: #fff;
}
.ai-cta-section h2 { font-weight: 900; font-size: 2rem; margin-bottom: 12px; letter-spacing: -.03em; }
.ai-cta-section p  { font-size: 1.05rem; opacity: .85; margin-bottom: 28px; }

/* ── FOOTER ───────────────────────────────────── */
.ai-footer { background: #0f172a; padding: 40px 0 24px; border-top: 1px solid rgba(255,255,255,.08); }

/* ── ERROR / SUCCESS TOAST ────────────────────── */
.ai-toast {
  position: fixed; bottom: 24px; right: 24px;
  background: var(--ai-dark); color: #fff;
  padding: 12px 20px; border-radius: 10px;
  font-size: .875rem; font-weight: 600;
  box-shadow: 0 8px 24px rgba(0,0,0,.2);
  transform: translateY(80px); opacity: 0;
  transition: all .3s ease; z-index: 9999;
  display: flex; align-items: center; gap: 8px;
}
.ai-toast.show   { transform: translateY(0); opacity: 1; }
.ai-toast.error  { border-left: 3px solid #ef4444; }
.ai-toast.success{ border-left: 3px solid #10b981; }

/* Download success state */
.ai-download-success {
  background: #f0fdf4; border: 1px solid #86efac;
  border-radius: 12px; padding: 20px; text-align: center;
  margin-top: 16px; display: none;
}
.ai-download-success i { font-size: 2rem; color: #16a34a; display: block; margin-bottom: 8px; }