/* ============================================
   Photo Resizer for Exams — style.css
   Color palette: Blues & whites, official feel
   ============================================ */

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

:root {
  --blue-900: #1e3a5f;
  --blue-800: #1a4480;
  --blue-700: #1a56db;
  --blue-600: #1d6ede;
  --blue-500: #3b82f6;
  --blue-100: #dbeafe;
  --blue-50:  #eff6ff;
  --green-500: #16a34a;
  --green-100: #dcfce7;
  --red-500:   #dc2626;
  --red-100:   #fee2e2;
  --amber-500: #d97706;
  --amber-100: #fef3c7;
  --gray-900: #111827;
  --gray-800: #1f2937;
  --gray-700: #374151;
  --gray-500: #6b7280;
  --gray-400: #9ca3af;
  --gray-200: #e5e7eb;
  --gray-100: #f3f4f6;
  --gray-50:  #f9fafb;
  --white: #ffffff;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,.1), 0 2px 6px rgba(0,0,0,.07);
  --shadow-lg: 0 10px 30px rgba(0,0,0,.12), 0 4px 12px rgba(0,0,0,.07);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --font: 'Inter', system-ui, -apple-system, sans-serif;
  --transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: #f0f4fa;
  color: var(--gray-800);
  line-height: 1.6;
  min-height: 100vh;
}

/* ============ HEADER ============ */
.site-header {
  background: linear-gradient(135deg, var(--blue-900) 0%, var(--blue-800) 60%, #1e4db7 100%);
  border-bottom: 3px solid var(--blue-700);
  padding: 0;
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 14px;
}

.header-logo a {
  display: flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
  color: inherit;
}

.logo-icon {
  flex-shrink: 0;
  filter: drop-shadow(0 2px 6px rgba(0,0,0,.25));
}

.logo-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.site-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--white);
  letter-spacing: -0.4px;
  line-height: 1.2;
}

.title-accent {
  color: #93c5fd;
  font-weight: 700;
}

.site-tagline {
  font-size: 0.78rem;
  color: #bfdbfe;
  font-weight: 400;
  letter-spacing: 0.01em;
}

.header-badge {
  display: flex;
  align-items: center;
  gap: 7px;
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.18);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 0.75rem;
  color: #bfdbfe;
  font-weight: 500;
  white-space: nowrap;
}

.badge-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #4ade80;
  box-shadow: 0 0 0 2px rgba(74,222,128,.3);
  animation: pulse-dot 2s ease infinite;
  flex-shrink: 0;
}

@keyframes pulse-dot {
  0%, 100% { box-shadow: 0 0 0 2px rgba(74,222,128,.3); }
  50%       { box-shadow: 0 0 0 5px rgba(74,222,128,.15); }
}

/* ============ MEGA NAVBAR ============ */
.mega-nav {
  background: var(--blue-800);
  border-bottom: 1px solid rgba(255,255,255,.08);
  position: relative;
  z-index: 100;
}

.mega-nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: stretch;
  gap: 0;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 12px 16px;
  font-family: var(--font);
  font-size: 0.84rem;
  font-weight: 600;
  color: #bfdbfe;
  text-decoration: none;
  border: none;
  background: none;
  cursor: pointer;
  transition: color var(--transition), background var(--transition);
  white-space: nowrap;
  border-bottom: 2px solid transparent;
}

.nav-link:hover,
.nav-item:hover > .nav-link {
  color: var(--white);
  background: rgba(255,255,255,.07);
}

.nav-link .nav-arrow {
  font-size: 0.6rem;
  transition: transform var(--transition);
}

.nav-item:hover .nav-arrow {
  transform: rotate(180deg);
}

/* Dropdown panel */
.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 200px;
  background: var(--white);
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  box-shadow: 0 12px 36px rgba(0,0,0,.15), 0 4px 12px rgba(0,0,0,.08);
  padding: 8px 0;
  opacity: 0;
  visibility: hidden;
  transform: translateY(4px);
  transition: opacity 0.2s, visibility 0.2s, transform 0.2s;
  z-index: 200;
}

.nav-item:hover > .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-dropdown a {
  display: block;
  padding: 9px 20px;
  font-size: 0.84rem;
  font-weight: 500;
  color: var(--gray-700);
  text-decoration: none;
  transition: background var(--transition), color var(--transition);
}

.nav-dropdown a:hover {
  background: var(--blue-50);
  color: var(--blue-700);
}

.nav-dropdown-divider {
  height: 1px;
  background: var(--gray-200);
  margin: 6px 0;
}

/* Mobile hamburger */
.nav-toggle {
  display: none;
  background: rgba(255,255,255,0.15);
  border: 2px solid rgba(255,255,255,0.35);
  border-radius: 8px;
  color: #ffffff;
  cursor: pointer;
  padding: 6px 10px;
  font-size: 1.35rem;
  line-height: 1;
  transition: background 0.2s, border-color 0.2s;
}

.nav-toggle:hover,
.nav-toggle:focus {
  background: rgba(255,255,255,0.28);
  border-color: rgba(255,255,255,0.6);
  outline: none;
}

/* Mobile nav drawer */
@media (max-width: 768px) {
  .nav-toggle {
    display: block;
    position: absolute;
    right: 14px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10;
  }

  .mega-nav {
    position: relative;
    min-height: 48px; /* ensure hamburger button is always visible */
  }

  .mega-nav-inner {
    flex-direction: column;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
    padding: 0 16px;
  }

  .mega-nav.open .mega-nav-inner {
    max-height: 600px;
    padding: 8px 16px 16px;
  }

  .nav-link {
    padding: 10px 12px;
    font-size: 0.88rem;
    justify-content: space-between;
  }

  .nav-dropdown {
    position: static;
    box-shadow: none;
    border-radius: 0;
    background: rgba(255,255,255,.04);
    padding: 0 0 0 16px;
    max-height: 0;
    overflow: hidden;
    opacity: 1;
    visibility: visible;
    transform: none;
    transition: max-height 0.3s ease;
  }

  .nav-item.open > .nav-dropdown {
    max-height: 400px;
    padding: 4px 0 4px 16px;
  }

  .nav-dropdown a {
    color: #93c5fd;
    padding: 8px 12px;
    font-size: 0.82rem;
  }

  .nav-dropdown a:hover {
    background: rgba(255,255,255,.06);
    color: var(--white);
  }
}

/* ============ TAB NAVIGATION ============ */
.tab-nav {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 16px;
  display: flex;
  gap: 0;
  margin-top: 28px;
  margin-bottom: -4px;
  position: relative;
  z-index: 2;
}

.tab-btn {
  flex: 1;
  padding: 14px 20px;
  border: 2px solid var(--gray-200);
  border-bottom: none;
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  background: var(--gray-50);
  color: var(--gray-500);
  font-family: var(--font);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border-color var(--transition), box-shadow var(--transition);
  position: relative;
  text-align: center;
  letter-spacing: 0.01em;
}

.tab-btn:not(:first-child) {
  margin-left: -2px;
}

.tab-btn:hover:not(.active) {
  background: var(--blue-50);
  color: var(--blue-700);
  border-color: var(--blue-100);
}

.tab-btn.active {
  background: var(--white);
  color: var(--blue-700);
  border-color: var(--blue-700);
  font-weight: 700;
  z-index: 3;
  box-shadow: 0 -3px 10px rgba(26,86,219,.08);
}

.tab-btn.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: -1px;
  right: -1px;
  height: 3px;
  background: var(--white);
}

.tab-btn:focus-visible {
  outline: 3px solid var(--blue-500);
  outline-offset: 2px;
  z-index: 4;
}

/* Tab panels */
.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
  animation: tabFadeIn 0.3s ease;
}

@keyframes tabFadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ============ MAIN LAYOUT ============ */
.main-content {
  padding: 36px 16px 60px;
  padding-top: 0;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

/* ============ CARDS ============ */
.card {
  background: var(--white);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
  padding: 32px 36px;
  border: 1px solid #e2e8f0;
}

/* First card in tab gets top border matching tab */
.tab-panel.active > .container > .card:first-child {
  border-top-left-radius: 0;
  border-top-right-radius: var(--radius-xl);
}

/* ============ SECTION LABEL ============ */
.section-label {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 14px;
}

.step-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--blue-700);
  color: white;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 999px;
  letter-spacing: 0.03em;
  flex-shrink: 0;
}

.step-badge--green {
  background: var(--green-500);
}

/* ============ PRESET BUTTONS ============ */
.preset-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 22px;
}

.preset-btn {
  flex: 1 1 auto;
  min-width: 110px;
  padding: 10px 16px;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-md);
  background: var(--white);
  color: var(--gray-700);
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition), color var(--transition), transform var(--transition), box-shadow var(--transition);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.preset-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--blue-700), var(--blue-600));
  opacity: 0;
  transition: opacity var(--transition);
}

.preset-btn span { position: relative; z-index: 1; }

.preset-btn:hover {
  border-color: var(--blue-600);
  color: var(--blue-700);
  background: var(--blue-50);
  transform: translateY(-1px);
  box-shadow: 0 3px 10px rgba(26,86,219,.15);
}

.preset-btn.active {
  border-color: var(--blue-700);
  background: var(--blue-700);
  color: var(--white);
  box-shadow: 0 4px 14px rgba(26,86,219,.3);
  transform: translateY(-1px);
}

.preset-btn.preset-custom {
  border-style: dashed;
  color: var(--gray-500);
}

.preset-btn.preset-custom.active {
  border-style: solid;
}

.preset-btn:focus-visible {
  outline: 3px solid var(--blue-500);
  outline-offset: 2px;
}

/* ============ FIELDS ROW ============ */
.fields-row {
  display: flex;
  align-items: flex-end;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 30px;
  padding: 20px 22px;
  background: var(--gray-50);
  border-radius: var(--radius-md);
  border: 1px solid var(--gray-200);
}

.field-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1 1 100px;
  min-width: 90px;
}

.field-label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--gray-600, #4b5563);
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.field-input {
  padding: 10px 14px;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 600;
  color: var(--gray-800);
  background: var(--white);
  transition: border-color var(--transition), box-shadow var(--transition);
  width: 100%;
}

.field-input:focus {
  outline: none;
  border-color: var(--blue-500);
  box-shadow: 0 0 0 3px rgba(59,130,246,.18);
}

.field-input::placeholder {
  font-weight: 400;
  color: var(--gray-400);
}

/* Remove number spinners */
.field-input::-webkit-inner-spin-button,
.field-input::-webkit-outer-spin-button { -webkit-appearance: none; margin: 0; }
.field-input[type=number] { -moz-appearance: textfield; }

.field-sep {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--gray-400);
  padding-bottom: 10px;
  flex-shrink: 0;
}

.field-divider {
  width: 1px;
  height: 44px;
  background: var(--gray-200);
  flex-shrink: 0;
  align-self: flex-end;
  margin-bottom: 2px;
}

/* ============ UPLOAD ZONE ============ */
.upload-zone {
  border: 2.5px dashed #93c5fd;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--blue-50) 0%, #f0f7ff 100%);
  padding: 44px 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition), transform var(--transition), box-shadow var(--transition);
  position: relative;
  user-select: none;
}

.upload-zone:hover,
.upload-zone.dragover {
  border-color: var(--blue-600);
  background: linear-gradient(135deg, #dbeafe 0%, #eff6ff 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(26,86,219,.12);
}

.upload-zone.dragover {
  border-color: var(--blue-700);
  background: #dbeafe;
}

.upload-zone.has-file {
  border-color: var(--green-500);
  background: linear-gradient(135deg, var(--green-100) 0%, #f0fdf4 100%);
}

.upload-zone:focus-visible {
  outline: 3px solid var(--blue-500);
  outline-offset: 3px;
}

.upload-icon {
  margin: 0 auto 14px;
  display: block;
  width: 52px;
  height: 52px;
  transition: transform var(--transition);
}

.upload-zone:hover .upload-icon,
.upload-zone.dragover .upload-icon { transform: translateY(-4px); }

.upload-main-text {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--blue-800);
  margin-bottom: 5px;
}

.upload-sub-text {
  font-size: 0.9rem;
  color: var(--gray-500);
}

.browse-link {
  color: var(--blue-700);
  font-weight: 600;
  cursor: pointer;
  background: none;
  border: none;
  font-family: var(--font);
  font-size: inherit;
  text-decoration: underline;
  text-decoration-color: transparent;
  transition: text-decoration-color var(--transition);
  padding: 0;
}

.browse-link:hover { text-decoration-color: var(--blue-700); }
.browse-link:focus-visible { outline: 2px solid var(--blue-500); border-radius: 2px; }

.upload-formats {
  font-size: 0.75rem;
  color: var(--gray-400);
  margin-top: 10px;
}

.upload-filename {
  margin-top: 14px;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  background: var(--white);
  border: 1px solid #bbf7d0;
  border-radius: 999px;
  padding: 5px 16px;
  font-size: 0.83rem;
  font-weight: 600;
  color: var(--green-500);
  box-shadow: var(--shadow-sm);
}

.upload-filename::before { content: '✓ '; }

/* ============ RESIZE ACTION ============ */
.resize-action {
  margin-top: 26px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.resize-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: linear-gradient(135deg, var(--blue-700) 0%, var(--blue-800) 100%);
  color: var(--white);
  border: none;
  border-radius: var(--radius-md);
  padding: 15px 44px;
  font-family: var(--font);
  font-size: 1.08rem;
  font-weight: 700;
  cursor: pointer;
  letter-spacing: 0.02em;
  box-shadow: 0 4px 18px rgba(26,86,219,.35);
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition), opacity var(--transition);
  position: relative;
  overflow: hidden;
}

.resize-btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,.12) 0%, transparent 50%);
  pointer-events: none;
}

.resize-btn:hover:not(:disabled) {
  background: linear-gradient(135deg, var(--blue-600) 0%, var(--blue-700) 100%);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(26,86,219,.4);
}

.resize-btn:active:not(:disabled) {
  transform: translateY(0);
  box-shadow: 0 2px 8px rgba(26,86,219,.3);
}

.resize-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  box-shadow: none;
}

.resize-btn:focus-visible {
  outline: 3px solid var(--blue-400, #60a5fa);
  outline-offset: 3px;
}

.resize-btn-icon { flex-shrink: 0; }

.resize-note {
  font-size: 0.8rem;
  color: var(--gray-400);
  text-align: center;
}

/* Loading state */
.resize-btn.loading {
  pointer-events: none;
}

.resize-btn.loading .resize-btn-icon {
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

/* ============ RESULT CARD ============ */
.result-card {
  animation: slideIn 0.4s cubic-bezier(0.34, 1.2, 0.64, 1);
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

.result-layout {
  display: flex;
  gap: 36px;
  flex-wrap: wrap;
  align-items: flex-start;
  margin-top: 4px;
}

.result-preview-wrap {
  flex: 0 0 auto;
}

.result-preview-frame {
  border: 3px solid var(--blue-100);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--gray-100);
  box-shadow: var(--shadow-md);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  max-width: 280px;
  min-width: 120px;
}

.result-img {
  display: block;
  max-width: 280px;
  max-height: 320px;
  width: auto;
  height: auto;
  object-fit: contain;
}

.result-info {
  flex: 1 1 260px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* Info grid */
.info-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.info-item {
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.info-label {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.info-value {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--gray-800);
}

/* Size meter */
.size-meter-wrap {
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.size-meter-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--gray-600, #4b5563);
}

.size-meter-bar {
  height: 10px;
  background: var(--gray-200);
  border-radius: 999px;
  overflow: hidden;
}

.size-meter-fill {
  height: 100%;
  border-radius: 999px;
  transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1), background 0.3s;
  width: 0%;
  background: var(--green-500);
}

.size-meter-fill.warn { background: var(--amber-500); }
.size-meter-fill.over { background: var(--red-500); }

/* ============ QUALITY SLIDER ============ */
.quality-slider-wrap {
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: var(--blue-50);
  border: 1px solid var(--blue-100);
  border-radius: var(--radius-md);
  padding: 16px 18px;
}

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

.quality-slider-title {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--blue-800);
  display: flex;
  align-items: center;
  gap: 6px;
}

.quality-slider-value {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--blue-700);
  background: var(--white);
  border: 1px solid var(--blue-100);
  border-radius: 999px;
  padding: 2px 12px;
}

.quality-slider-track {
  position: relative;
  padding: 4px 0;
}

.quality-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 8px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--blue-100) 0%, var(--blue-500) 50%, var(--blue-700) 100%);
  outline: none;
  cursor: pointer;
  transition: box-shadow var(--transition);
}

.quality-slider:hover {
  box-shadow: 0 0 0 3px rgba(26,86,219,.1);
}

.quality-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--white);
  border: 3px solid var(--blue-700);
  box-shadow: 0 2px 8px rgba(26,86,219,.25);
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
}

.quality-slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
  box-shadow: 0 3px 12px rgba(26,86,219,.35);
}

.quality-slider::-webkit-slider-thumb:active {
  transform: scale(1.05);
  background: var(--blue-50);
}

.quality-slider::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--white);
  border: 3px solid var(--blue-700);
  box-shadow: 0 2px 8px rgba(26,86,219,.25);
  cursor: pointer;
}

.quality-slider-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.7rem;
  color: var(--gray-400);
  font-weight: 500;
  margin-top: 2px;
}

/* Download actions */
.download-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--blue-700) 0%, var(--blue-800) 100%);
  color: var(--white);
  border: none;
  border-radius: var(--radius-md);
  padding: 13px 28px;
  font-family: var(--font);
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(26,86,219,.3);
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
}

.download-btn:hover {
  background: linear-gradient(135deg, var(--blue-600) 0%, var(--blue-700) 100%);
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(26,86,219,.35);
}

.reset-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--white);
  color: var(--gray-600, #4b5563);
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-md);
  padding: 11px 22px;
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: border-color var(--transition), color var(--transition), background var(--transition);
}

.reset-btn:hover {
  border-color: var(--blue-600);
  color: var(--blue-700);
  background: var(--blue-50);
}

/* Tips */
.result-tips {
  background: var(--blue-50);
  border: 1px solid var(--blue-100);
  border-radius: var(--radius-md);
  padding: 14px 16px;
}

.tip-title {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--blue-800);
  margin-bottom: 7px;
}

.tip-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.tip-list li {
  font-size: 0.8rem;
  color: var(--blue-800);
  padding-left: 14px;
  position: relative;
}

.tip-list li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--blue-600);
}

/* ============ INFO SECTION ============ */
.info-section {
  padding: 4px 0;
}

.info-section-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--gray-700);
  margin-bottom: 16px;
  padding-left: 4px;
}

.info-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}

.info-card {
  background: var(--white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-200);
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition);
}

.info-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.info-card-header {
  background: linear-gradient(135deg, var(--blue-800) 0%, var(--blue-700) 100%);
  color: var(--white);
  font-size: 0.88rem;
  font-weight: 700;
  padding: 11px 16px;
  letter-spacing: 0.02em;
}

.info-card-body {
  padding: 12px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.info-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.83rem;
}

.info-row dt {
  color: var(--gray-500);
  font-weight: 500;
}

.info-row dd {
  font-weight: 700;
  color: var(--gray-800);
}

/* ============ FOOTER ============ */
.site-footer {
  background: linear-gradient(180deg, var(--blue-900) 0%, #152d4a 100%);
  color: #94a3b8;
  font-size: 0.84rem;
  line-height: 1.7;
  padding: 0;
}

.footer-main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 48px 24px 36px;
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr;
  gap: 40px;
}

.footer-brand .footer-logo-group {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
}

.footer-brand .footer-logo-group svg {
  flex-shrink: 0;
}

.footer-brand .footer-brand-name {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--white);
}

.footer-brand .footer-brand-name span {
  color: #93c5fd;
  font-weight: 700;
}

.footer-brand .footer-tagline {
  color: #7f9cc3;
  font-size: 0.84rem;
  line-height: 1.65;
  max-width: 340px;
}

.footer-column h4 {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--white);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
}

.footer-column ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-column ul li a {
  color: #7f9cc3;
  text-decoration: none;
  font-size: 0.84rem;
  font-weight: 500;
  transition: color var(--transition);
}

.footer-column ul li a:hover {
  color: var(--white);
}

/* Popular tools strip */
.footer-popular {
  border-top: 1px solid rgba(255,255,255,.08);
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px 24px 20px;
}

.footer-popular h4 {
  font-size: 0.75rem;
  font-weight: 700;
  color: #93c5fd;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 12px;
}

.footer-popular-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
}

.footer-popular-links a {
  font-size: 0.78rem;
  color: #5a7fa5;
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition);
  white-space: nowrap;
}

.footer-popular-links a:hover {
  color: #bfdbfe;
}

/* Copyright bar */
.footer-copyright {
  border-top: 1px solid rgba(255,255,255,.06);
  text-align: center;
  padding: 16px 24px;
  font-size: 0.76rem;
  color: #4a6a8a;
  font-weight: 500;
}

/* Footer responsive */
@media (max-width: 768px) {
  .footer-main {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 36px 20px 28px;
  }

  .footer-brand .footer-tagline {
    max-width: 100%;
  }

  .footer-popular {
    padding: 20px 20px 16px;
  }

  .footer-popular-links {
    gap: 4px 12px;
  }
}

.footer-sub {
  color: #60a5fa;
  font-size: 0.77rem;
  margin-top: 4px;
}
/* ============ REFERENCE TABLE ============ */
.ref-section {
  max-width: 900px;
  margin: 0 auto;
  padding: 20px 16px 48px;
}

.ref-section-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--gray-800);
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}

.ref-section-subtitle {
  font-size: 0.88rem;
  color: var(--gray-500);
  margin-bottom: 20px;
  line-height: 1.5;
}

.ref-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-sm);
}

.ref-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.84rem;
  min-width: 700px;
}

.ref-table thead {
  background: linear-gradient(135deg, var(--blue-800), var(--blue-700));
}

.ref-table thead th {
  color: var(--white);
  font-weight: 700;
  font-size: 0.76rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 12px 16px;
  text-align: left;
  white-space: nowrap;
}

.ref-table tbody tr {
  background: var(--white);
  transition: background var(--transition);
}

.ref-table tbody tr:nth-child(even) {
  background: var(--gray-50);
}

.ref-table tbody tr:hover {
  background: var(--blue-50);
}

.ref-table tbody td {
  padding: 11px 16px;
  color: var(--gray-700);
  font-weight: 500;
  border-top: 1px solid var(--gray-200);
  white-space: nowrap;
}

.ref-table tbody td:first-child {
  font-weight: 700;
  color: var(--gray-800);
}

.ref-category {
  background: var(--blue-50) !important;
}

.ref-category td {
  font-weight: 700 !important;
  color: var(--blue-800) !important;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-top: 2px solid var(--blue-100) !important;
  padding: 8px 16px !important;
}

.ref-disclaimer {
  margin-top: 14px;
  padding: 12px 16px;
  background: var(--amber-100);
  border: 1px solid #fcd34d;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  color: #92400e;
  font-weight: 500;
  line-height: 1.5;
}

@media (max-width: 640px) {
  .ref-section {
    padding: 16px 12px 36px;
  }

  .ref-section-title {
    font-size: 1.1rem;
  }
}

/* ============ TOAST ============ */
.toast {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--gray-900);
  color: var(--white);
  border-radius: var(--radius-md);
  padding: 12px 24px;
  font-size: 0.88rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s, transform 0.3s cubic-bezier(0.34,1.2,0.64,1);
  z-index: 9999;
  white-space: nowrap;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
  pointer-events: auto;
}

.toast.toast--error { background: var(--red-500); }
.toast.toast--success { background: var(--green-500); }

/* ============ RESPONSIVE ============ */
@media (max-width: 640px) {
  .header-inner { flex-direction: column; align-items: flex-start; gap: 10px; }
  .header-badge { font-size: 0.7rem; padding: 5px 10px; }
  .site-title { font-size: 1.25rem; }
  .card { padding: 22px 18px; border-radius: var(--radius-lg); }
  .preset-row { gap: 8px; }
  .preset-btn { min-width: 80px; font-size: 0.78rem; padding: 9px 10px; }
  .fields-row { gap: 10px; padding: 14px 14px; }
  .field-divider { display: none; }
  .upload-zone { padding: 32px 16px; }
  .resize-btn { padding: 14px 32px; font-size: 1rem; }
  .result-layout { flex-direction: column; gap: 22px; }
  .result-preview-frame { max-width: 100%; }
  .result-img { max-width: 100%; }
  .info-grid { grid-template-columns: 1fr 1fr; }
  .download-actions { flex-direction: column; }
  .download-btn, .reset-btn { justify-content: center; }

  /* Tabs responsive */
  .tab-nav { gap: 0; }
  .tab-btn { font-size: 0.76rem; padding: 11px 8px; }
}

@media (max-width: 400px) {
  .info-grid { grid-template-columns: 1fr; }
  .preset-btn { flex: 1 1 40%; }
  .tab-btn { font-size: 0.7rem; padding: 10px 6px; }
}

/* ============ EXAM INTRO SECTION ============ */
.exam-intro-wrap {
  background: linear-gradient(135deg, var(--blue-50) 0%, #f0f7ff 60%, #e8f0fe 100%);
  border-bottom: 1px solid #c7d9f9;
  padding: 36px 24px 32px;
}

.exam-intro-wrap .container {
  gap: 12px;
}

.exam-intro-h1 {
  font-size: 1.65rem;
  font-weight: 800;
  color: var(--blue-900);
  line-height: 1.25;
  letter-spacing: -0.5px;
}

.exam-intro-text {
  font-size: 0.97rem;
  color: var(--gray-700);
  line-height: 1.7;
  max-width: 780px;
}

.exam-intro-text strong {
  color: var(--blue-800);
  font-weight: 700;
}

/* Exam pages: main-content starts right after intro (no top gap) */
.exam-intro-wrap + .main-content {
  padding-top: 32px;
}

/* Exam pages: first card gets normal full radius */
.exam-intro-wrap + .main-content .card:first-child {
  border-radius: var(--radius-xl);
}

@media (max-width: 600px) {
  .exam-intro-h1 { font-size: 1.2rem; }
  .exam-intro-wrap { padding: 24px 16px 20px; }
}