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

:root {
  --blue:        #2563eb;
  --blue-dark:   #1d4ed8;
  --blue-tint:   #eff6ff;
  --green:       #16a34a;
  --green-tint:  #f0fdf4;
  --green-border:#bbf7d0;
  --yellow-bg:   #fef3c7;
  --yellow-border:#fcd34d;
  --yellow-text: #92400e;
  --red:         #dc2626;
  --bg:          #f1f5f9;
  --surface:     #ffffff;
  --border:      #e2e8f0;
  --text:        #1e293b;
  --muted:       #64748b;
  --locked-bg:   #f8fafc;
  --locked-text: #94a3b8;
  --header-bg:   #0f172a;
  --radius:      12px;
  --shadow:      0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.05);
  --shadow-md:   0 4px 6px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.06);
}

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: var(--blue); }
a:hover { color: var(--blue-dark); }

.hidden { display: none !important; }

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ─── Browser banner ──────────────────────────────────────────────────────── */
.browser-banner {
  background: var(--yellow-bg);
  border-bottom: 1px solid var(--yellow-border);
  color: var(--yellow-text);
  padding: 12px 20px;
  text-align: center;
  font-size: 0.875rem;
}
.browser-banner a { color: var(--yellow-text); font-weight: 600; text-decoration: underline; }

/* ─── Header ──────────────────────────────────────────────────────────────── */
.site-header {
  background: var(--header-bg);
  padding: 36px 0 30px;
  text-align: center;
  border-bottom: 3px solid var(--blue);
  flex-shrink: 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.brand-name {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -1px;
  color: #fff;
}

.brand-badge {
  background: var(--blue);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 100px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  align-self: center;
}

.brand-tagline {
  font-size: 0.875rem;
  color: #94a3b8;
  letter-spacing: 0.2px;
}

/* ─── Main layout ─────────────────────────────────────────────────────────── */
main.container {
  padding-top: 32px;
  padding-bottom: 56px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  flex: 1;
}

/* ─── Windows driver notice ───────────────────────────────────────────────── */
.notice-card {
  background: #fffbeb;
  border: 1px solid #fcd34d;
  border-left: 4px solid #d97706;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.notice-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 24px;
  border-bottom: 1px solid #fde68a;
  background: #fef3c7;
}

.notice-icon {
  font-size: 1.2rem;
  color: #d97706;
  flex-shrink: 0;
}

.notice-header h2 {
  font-size: 1.05rem;
  font-weight: 600;
  color: #92400e;
}

.notice-body {
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.notice-body p {
  font-size: 0.875rem;
  color: #78350f;
  line-height: 1.65;
}

.notice-body ol {
  padding-left: 20px;
  display: flex;
  flex-direction: column;
  gap: 7px;
  font-size: 0.875rem;
  color: #78350f;
  line-height: 1.65;
}

.notice-body strong { color: #92400e; font-weight: 600; }
.notice-body a { color: #92400e; font-weight: 600; }
.notice-body a:hover { color: #78350f; }

/* ─── Step cards ──────────────────────────────────────────────────────────── */
.step-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: box-shadow 0.2s, opacity 0.3s;
}

.step-card:not(.locked):hover {
  box-shadow: var(--shadow-md);
}

.step-card.locked {
  background: var(--locked-bg);
  opacity: 0.5;
  pointer-events: none;
  user-select: none;
}

.step-header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
  background: #fafbfd;
}

.step-card.locked .step-header {
  border-bottom-color: transparent;
}

.step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--blue);
  color: #fff;
  border-radius: 50%;
  font-weight: 700;
  font-size: 0.9rem;
  flex-shrink: 0;
  transition: background 0.2s;
}

.step-card.locked .step-number {
  background: var(--locked-text);
}

.step-card.complete .step-number {
  background: var(--green);
}

.step-header h2 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
}

.step-card.locked .step-header h2 {
  color: var(--locked-text);
}

.step-body {
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

/* ─── Radio model grid ────────────────────────────────────────────────────── */
.radio-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

@media (max-width: 520px) {
  .radio-grid { grid-template-columns: 1fr; }
}

.radio-btn {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 18px 14px;
  background: var(--bg);
  border: 2px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  transition: border-color 0.15s, background 0.15s, box-shadow 0.15s;
}

.radio-btn strong {
  font-size: 0.95rem;
  color: var(--text);
  font-weight: 600;
}

.radio-btn span {
  font-size: 0.8rem;
  color: var(--muted);
}

.radio-btn:hover {
  border-color: var(--blue);
  background: var(--blue-tint);
}

.radio-btn.selected {
  border-color: var(--blue);
  background: var(--blue-tint);
  box-shadow: 0 0 0 3px rgba(37,99,235,.12);
}

.radio-btn.selected strong {
  color: var(--blue);
}

/* ─── Info box ────────────────────────────────────────────────────────────── */
.info-box {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-left: 4px solid var(--blue);
  border-radius: 8px;
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.info-box h3 {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text);
  text-transform: uppercase;
  letter-spacing: 0.4px;
}

.info-box p, .info-box li {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.65;
}

.info-box ol {
  padding-left: 20px;
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.info-box strong { color: var(--text); font-weight: 600; }

.info-box code {
  background: var(--border);
  padding: 1px 5px;
  border-radius: 4px;
  font-size: 0.85em;
  font-family: 'Menlo', 'Consolas', monospace;
}

/* ─── File picker ─────────────────────────────────────────────────────────── */
.file-picker-area {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  border: 2px dashed var(--border);
  border-radius: 10px;
  padding: 22px 24px;
  transition: border-color 0.15s, background 0.15s;
}

.file-picker-area.drag-over {
  border-color: var(--blue);
  background: var(--blue-tint);
}

.hint {
  font-size: 0.82rem;
  color: var(--locked-text);
}

.file-selected {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--green);
}

.file-selected::before { content: '\2713\00a0'; }

/* ─── Summary box ─────────────────────────────────────────────────────────── */
.summary-box {
  background: var(--green-tint);
  border: 1px solid var(--green-border);
  border-radius: 8px;
  padding: 14px 18px;
  font-size: 0.875rem;
  color: #166534;
  line-height: 2;
}

/* ─── Buttons ─────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, transform 0.1s, box-shadow 0.15s;
  border: 2px solid transparent;
  text-decoration: none;
  white-space: nowrap;
}

.btn:active:not(:disabled) { transform: scale(0.98); }

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

.btn-primary:hover:not(:disabled) {
  background: var(--blue-dark);
  border-color: var(--blue-dark);
  box-shadow: 0 2px 8px rgba(37,99,235,.3);
}

.btn-primary:disabled {
  background: #cbd5e1;
  border-color: #cbd5e1;
  color: #94a3b8;
  cursor: not-allowed;
}

.btn-outline {
  background: #fff;
  color: var(--blue);
  border-color: var(--blue);
}

.btn-outline:hover { background: var(--blue-tint); }

.btn-flash {
  padding: 13px 30px;
  font-size: 1rem;
  letter-spacing: 0.2px;
}

/* ─── Progress ────────────────────────────────────────────────────────────── */
.progress-area {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.progress-bar-track {
  height: 10px;
  background: var(--border);
  border-radius: 100px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--blue), #60a5fa);
  border-radius: 100px;
  transition: width 0.35s ease;
}

.progress-label {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--muted);
  letter-spacing: 0.3px;
}

/* ─── Status text ─────────────────────────────────────────────────────────── */
.status-text {
  font-size: 0.875rem;
  color: var(--muted);
  min-height: 1.4em;
}

.status-text.success { color: var(--green); font-weight: 600; }
.status-text.error   { color: var(--red);   font-weight: 600; }

/* ─── Footer ──────────────────────────────────────────────────────────────── */
.site-footer {
  background: var(--header-bg);
  color: #64748b;
  text-align: center;
  padding: 22px 20px;
  font-size: 0.825rem;
  flex-shrink: 0;
}

.site-footer a { color: #94a3b8; }
.site-footer a:hover { color: #e2e8f0; }