/* ============================================
   文件快船 — Ocean Express Design System
   ============================================ */

/* ---------- Design Tokens ---------- */
:root {
  /* Brand palette — Ocean teal */
  --brand-50:  #ecfdf9;
  --brand-100: #ccfbf1;
  --brand-200: #99f6e4;
  --brand-300: #5eead4;
  --brand-400: #2dd4bf;
  --brand-500: #14b8a6;
  --brand-600: #0d9488;
  --brand-700: #0f766e;
  --brand-800: #115e59;
  --brand-900: #134e4a;

  /* Accent — warm amber for urgency / expiration */
  --accent-500: #f59e0b;
  --accent-600: #d97706;

  /* Semantic */
  --success: #10b981;
  --danger:  #ef4444;
  --danger-soft: #fef2f2;

  /* Surfaces */
  --bg:          #f8fafc;
  --bg-pattern:  rgba(13, 148, 136, 0.03);
  --surface:     #ffffff;
  --surface-alt: #f1f5f9;
  --surface-hover: #f8fafc;

  /* Text */
  --text:         #0f172a;
  --text-secondary: #475569;
  --text-muted:   #94a3b8;
  --text-on-brand: #ffffff;

  /* Borders */
  --border:         #e2e8f0;
  --border-strong:  #cbd5e1;
  --border-brand:   var(--brand-300);

  /* Shadows */
  --shadow-sm:  0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md:  0 4px 12px rgba(0, 0, 0, 0.06), 0 1px 3px rgba(0, 0, 0, 0.04);
  --shadow-lg:  0 12px 32px rgba(0, 0, 0, 0.08), 0 4px 8px rgba(0, 0, 0, 0.04);
  --shadow-brand: 0 8px 24px rgba(13, 148, 136, 0.18);

  /* Radius */
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 16px;
  --r-full: 999px;

  /* Spacing scale */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 20px;
  --sp-6: 24px;
  --sp-8: 32px;
  --sp-10: 40px;
  --sp-12: 48px;

  /* Typography */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Fira Code", ui-monospace,
               Menlo, Consolas, monospace;

  --text-xs:   12px;
  --text-sm:   14px;
  --text-base: 16px;
  --text-lg:   18px;
  --text-xl:   22px;
  --text-2xl:  28px;
  --text-3xl:  36px;

  --lh-tight:  1.3;
  --lh-normal: 1.5;
  --lh-relaxed: 1.625;

  /* Motion */
  --ease-out:    cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --dur-fast:  150ms;
  --dur-base:  250ms;
  --dur-slow:  400ms;
}

/* ---------- Dark Mode ---------- */
@media (prefers-color-scheme: dark) {
  :root {
    --bg:          #0f172a;
    --bg-pattern:  rgba(45, 212, 191, 0.04);
    --surface:     #1e293b;
    --surface-alt: #334155;
    --surface-hover: #334155;

    --text:         #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted:   #64748b;

    --border:         #334155;
    --border-strong:  #475569;
    --border-brand:   var(--brand-700);

    --danger-soft: #450a0a;

    --shadow-sm:  0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-md:  0 4px 12px rgba(0, 0, 0, 0.3), 0 1px 3px rgba(0, 0, 0, 0.2);
    --shadow-lg:  0 12px 32px rgba(0, 0, 0, 0.4), 0 4px 8px rgba(0, 0, 0, 0.2);
    --shadow-brand: 0 8px 24px rgba(20, 184, 166, 0.25);
  }
}

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--lh-normal);
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow-x: hidden;
}

/* Subtle wave pattern background */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -10%, var(--brand-50), transparent),
    repeating-linear-gradient(
      135deg,
      transparent,
      transparent 60px,
      var(--bg-pattern) 60px,
      var(--bg-pattern) 61px
    );
  pointer-events: none;
  z-index: 0;
}

@media (prefers-color-scheme: dark) {
  body::before {
    background-image:
      radial-gradient(ellipse 80% 50% at 50% -10%, rgba(20, 184, 166, 0.08), transparent),
      repeating-linear-gradient(
        135deg,
        transparent,
        transparent 60px,
        var(--bg-pattern) 60px,
        var(--bg-pattern) 61px
      );
  }
}

/* ---------- Layout ---------- */
.container {
  max-width: 560px;
  margin: 0 auto;
  padding: var(--sp-10) var(--sp-5);
  width: 100%;
  position: relative;
  z-index: 1;
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

/* ---------- Header ---------- */
header {
  text-align: center;
  margin-bottom: var(--sp-8);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-3);
}

.logo-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--brand-500), var(--brand-700));
  border-radius: var(--r-md);
  box-shadow: var(--shadow-brand);
  flex-shrink: 0;
}

.logo-icon svg {
  width: 24px;
  height: 24px;
  color: var(--text-on-brand);
}

.logo h1 {
  font-size: var(--text-2xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--brand-700), var(--brand-500));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

@media (prefers-color-scheme: dark) {
  .logo h1 {
    background: linear-gradient(135deg, var(--brand-300), var(--brand-400));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
  }
}

.tagline {
  color: var(--text-muted);
  font-size: var(--text-sm);
  margin-top: var(--sp-2);
  letter-spacing: 0.01em;
}

/* ---------- Card ---------- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  padding: var(--sp-8);
  box-shadow: var(--shadow-md);
}

/* ---------- Tab Bar ---------- */
.tab-bar {
  display: flex;
  gap: var(--sp-1);
  margin-bottom: var(--sp-5);
  border-bottom: 2px solid var(--border);
  padding: 0 var(--sp-1);
}

.tab {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-4);
  border: none;
  background: transparent;
  font-family: inherit;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  position: relative;
  transition: color var(--dur-fast) var(--ease-out);
  white-space: nowrap;
  margin-bottom: -2px;
}

.tab svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.tab:hover {
  color: var(--text-secondary);
}

.tab:focus-visible {
  outline: 2px solid var(--brand-500);
  outline-offset: 2px;
  border-radius: var(--r-sm);
}

.tab.active {
  color: var(--brand-600);
  font-weight: 600;
}

.tab.active::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--brand-500);
  border-radius: var(--r-full) var(--r-full) 0 0;
  animation: tabSlide var(--dur-base) var(--ease-out);
}

@media (prefers-color-scheme: dark) {
  .tab.active {
    color: var(--brand-400);
  }
  .tab.active::after {
    background: var(--brand-400);
  }
}

@keyframes tabSlide {
  from { transform: scaleX(0); }
  to   { transform: scaleX(1); }
}

/* ---------- Tab Panels ---------- */
.tab-panel {
  display: none;
  animation: fadeIn var(--dur-base) var(--ease-out);
}

.tab-panel.active {
  display: block;
}

/* ---------- Pickup Form ---------- */
.pickup-hint {
  margin-top: var(--sp-4);
  color: var(--text-muted);
  font-size: var(--text-xs);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  line-height: var(--lh-relaxed);
}

.pickup-hint svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

#pickup-code {
  font-family: var(--font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* ---------- Drop Zone ---------- */
.drop-zone {
  border: 2px dashed var(--border-strong);
  border-radius: var(--r-lg);
  padding: var(--sp-12) var(--sp-6);
  text-align: center;
  background: var(--surface-alt);
  transition: border-color var(--dur-base) var(--ease-out),
              background var(--dur-base) var(--ease-out),
              transform var(--dur-base) var(--ease-out);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.drop-zone::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at var(--mx, 50%) var(--my, 50%),
              var(--brand-50) 0%, transparent 60%);
  opacity: 0;
  transition: opacity var(--dur-slow) var(--ease-out);
  pointer-events: none;
}

@media (prefers-color-scheme: dark) {
  .drop-zone::after {
    background: radial-gradient(circle at var(--mx, 50%) var(--my, 50%),
                rgba(20, 184, 166, 0.08) 0%, transparent 60%);
  }
}

.drop-zone:hover {
  border-color: var(--brand-400);
  background: var(--surface-hover);
}

.drop-zone:hover::after {
  opacity: 1;
}

.drop-zone.drag-over {
  border-color: var(--brand-500);
  background: var(--brand-50);
  transform: scale(1.01);
}

@media (prefers-color-scheme: dark) {
  .drop-zone.drag-over {
    background: rgba(20, 184, 166, 0.08);
  }
}

.drop-zone-content {
  position: relative;
  z-index: 1;
}

.drop-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto var(--sp-3);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--brand-50);
  border-radius: var(--r-full);
  color: var(--brand-600);
  transition: transform var(--dur-base) var(--ease-spring);
}

@media (prefers-color-scheme: dark) {
  .drop-icon {
    background: rgba(20, 184, 166, 0.12);
    color: var(--brand-400);
  }
}

.drop-zone:hover .drop-icon {
  transform: translateY(-4px) scale(1.05);
}

.drop-icon svg {
  width: 28px;
  height: 28px;
}

.drop-zone p {
  color: var(--text-secondary);
  font-size: var(--text-base);
}

.drop-or {
  color: var(--text-muted);
  font-size: var(--text-sm);
  margin: var(--sp-2) 0;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: 10px 22px;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  font-family: inherit;
  font-size: var(--text-sm);
  font-weight: 500;
  line-height: 1;
  cursor: pointer;
  text-decoration: none;
  color: var(--text-secondary);
  background: var(--surface-alt);
  transition: all var(--dur-fast) var(--ease-out);
  white-space: nowrap;
  user-select: none;
}

.btn:hover {
  background: var(--surface-hover);
  border-color: var(--border-strong);
}

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

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.btn-primary {
  background: var(--brand-600);
  color: var(--text-on-brand);
  border-color: var(--brand-600);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: var(--brand-700);
  border-color: var(--brand-700);
  box-shadow: var(--shadow-brand);
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: var(--shadow-sm);
}

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--brand-300);
  color: var(--brand-700);
}

@media (prefers-color-scheme: dark) {
  .btn-outline {
    border-color: var(--brand-700);
    color: var(--brand-400);
  }
}

.btn-outline:hover {
  background: var(--brand-50);
  border-color: var(--brand-500);
  color: var(--brand-700);
}

@media (prefers-color-scheme: dark) {
  .btn-outline:hover {
    background: rgba(20, 184, 166, 0.1);
    color: var(--brand-300);
  }
}

.btn-full {
  width: 100%;
}

.btn-small {
  padding: 6px 14px;
  font-size: var(--text-xs);
}

/* ---------- Forms ---------- */
.form-group {
  margin-top: var(--sp-5);
}

.form-group label {
  display: block;
  margin-bottom: var(--sp-2);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-secondary);
}

.form-group select,
.form-group input[type="text"] {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  font-family: inherit;
  font-size: var(--text-sm);
  color: var(--text);
  background: var(--surface);
  transition: border-color var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-fast) var(--ease-out);
  appearance: none;
}

.form-group select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 40px;
  cursor: pointer;
}

.form-group select:focus,
.form-group input[type="text"]:focus {
  outline: none;
  border-color: var(--brand-500);
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.12);
}

.input-row {
  display: flex;
  gap: var(--sp-2);
}

.input-row input {
  flex: 1;
  padding: 11px 14px;
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  font-family: inherit;
  font-size: var(--text-sm);
  color: var(--text);
  background: var(--surface);
  transition: border-color var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-fast) var(--ease-out);
}

.input-row input:focus {
  outline: none;
  border-color: var(--brand-500);
  box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.12);
}

.size-hint {
  color: var(--text-muted);
  font-size: var(--text-xs);
  display: flex;
  align-items: center;
  gap: var(--sp-1);
}

.size-hint svg {
  width: 14px;
  height: 14px;
}

/* ---------- File Info ---------- */
.file-info {
  margin-top: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  background: var(--brand-50);
  border: 1px solid var(--brand-100);
  border-radius: var(--r-sm);
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  animation: slideDown var(--dur-base) var(--ease-out);
}

@media (prefers-color-scheme: dark) {
  .file-info {
    background: rgba(20, 184, 166, 0.08);
    border-color: var(--brand-800);
  }
}

.file-info-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  border-radius: var(--r-sm);
  color: var(--brand-600);
  flex-shrink: 0;
}

@media (prefers-color-scheme: dark) {
  .file-info-icon {
    color: var(--brand-400);
  }
}

.file-info-icon svg {
  width: 20px;
  height: 20px;
}

.file-info-text {
  flex: 1;
  min-width: 0;
}

.file-info-text #file-name {
  font-weight: 600;
  font-size: var(--text-sm);
  color: var(--text);
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.file-info-text #file-size {
  color: var(--text-muted);
  font-size: var(--text-xs);
}

/* ---------- Progress ---------- */
.progress-container {
  margin-top: var(--sp-5);
  text-align: center;
  animation: fadeIn var(--dur-base) var(--ease-out);
}

.progress-bar {
  height: 6px;
  background: var(--surface-alt);
  border-radius: var(--r-full);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--brand-400), var(--brand-600));
  width: 0%;
  border-radius: var(--r-full);
  transition: width var(--dur-slow) var(--ease-out);
  position: relative;
}

.progress-fill::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.3),
    transparent
  );
  animation: shimmer 1.5s infinite;
}

#progress-text {
  margin-top: var(--sp-2);
  color: var(--text-muted);
  font-size: var(--text-xs);
  font-variant-numeric: tabular-nums;
}

/* ---------- Result Card ---------- */
.result-card {
  margin-top: var(--sp-6);
  text-align: center;
  animation: slideUp var(--dur-slow) var(--ease-spring);
}

.result-card h2 {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--text);
  margin-bottom: var(--sp-2);
}

.success-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto var(--sp-3);
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--success), #059669);
  border-radius: var(--r-full);
  color: white;
  box-shadow: 0 4px 16px rgba(16, 185, 129, 0.25);
}

.success-icon svg {
  width: 28px;
  height: 28px;
}

.result-label {
  margin-top: var(--sp-4);
  color: var(--text-muted);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 500;
}

.code-display {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-3);
  margin: var(--sp-3) 0 var(--sp-2);
  padding: var(--sp-4);
  background: var(--surface-alt);
  border-radius: var(--r-md);
  border: 1px dashed var(--border-strong);
}

.code-display span {
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--brand-600);
  text-shadow: 0 0 24px rgba(20, 184, 166, 0.15);
}

@media (prefers-color-scheme: dark) {
  .code-display span {
    color: var(--brand-400);
  }
}

.result-meta {
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  margin-top: var(--sp-3);
}

.result-expire {
  color: var(--accent-600);
  font-size: var(--text-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-1);
}

.result-expire svg {
  width: 15px;
  height: 15px;
}

.result-link {
  font-size: var(--text-xs);
  word-break: break-all;
  color: var(--text-muted);
  font-family: var(--font-mono);
  padding: var(--sp-2) var(--sp-3);
  background: var(--surface-alt);
  border-radius: var(--r-sm);
  margin-top: var(--sp-2);
}

/* ---------- Download Page ---------- */
.download-card {
  text-align: center;
}

.download-card h2 {
  font-size: var(--text-lg);
  font-weight: 600;
  margin-bottom: var(--sp-3);
  word-break: break-all;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
}

.download-card h2 svg {
  width: 22px;
  height: 22px;
  color: var(--brand-600);
  flex-shrink: 0;
}

@media (prefers-color-scheme: dark) {
  .download-card h2 svg {
    color: var(--brand-400);
  }
}

.download-meta {
  display: flex;
  justify-content: center;
  gap: var(--sp-6);
  margin-bottom: var(--sp-5);
  padding-bottom: var(--sp-4);
  border-bottom: 1px solid var(--border);
}

.meta-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.meta-label {
  font-size: var(--text-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.meta-value {
  font-size: var(--text-sm);
  color: var(--text);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

/* ---------- Error Page ---------- */
.error-card {
  text-align: center;
}

.error-card .error-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto var(--sp-4);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--danger-soft);
  border-radius: var(--r-full);
  color: var(--danger);
}

.error-card .error-icon svg {
  width: 28px;
  height: 28px;
}

.error-card h2 {
  font-size: var(--text-xl);
  font-weight: 700;
  margin-bottom: var(--sp-2);
}

.error-card p {
  color: var(--text-secondary);
  margin-bottom: var(--sp-5);
  line-height: var(--lh-relaxed);
}

/* ---------- Error Message (password) ---------- */
.error-msg {
  color: var(--danger);
  font-size: var(--text-xs);
  margin-top: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  background: var(--danger-soft);
  border-radius: var(--r-sm);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  animation: shake var(--dur-base) var(--ease-out);
}

.error-msg svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

/* ---------- Back Link ---------- */
.back-link {
  margin-top: var(--sp-5);
  text-align: center;
}

.back-link a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: var(--text-sm);
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  transition: color var(--dur-fast) var(--ease-out);
}

.back-link a:hover {
  color: var(--brand-600);
}

@media (prefers-color-scheme: dark) {
  .back-link a:hover {
    color: var(--brand-400);
  }
}

.back-link svg {
  width: 16px;
  height: 16px;
}

/* ---------- Footer ---------- */
.app-footer {
  text-align: center;
  padding: var(--sp-5);
  color: var(--text-muted);
  font-size: var(--text-xs);
  position: relative;
  z-index: 1;
}

/* ---------- Copy Button Feedback ---------- */
.btn.copied {
  background: var(--success) !important;
  color: white !important;
  border-color: var(--success) !important;
}

/* ---------- Utilities ---------- */
.hidden {
  display: none !important;
}

/* ---------- Animations ---------- */
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes shimmer {
  0%   { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25%  { transform: translateX(-4px); }
  75%  { transform: translateX(4px); }
}

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

  .progress-fill::after {
    display: none;
  }
}

/* ---------- Responsive ---------- */
@media (max-width: 520px) {
  .container {
    padding: var(--sp-5) var(--sp-3);
  }

  .logo h1 {
    font-size: var(--text-xl);
  }

  .logo-icon {
    width: 36px;
    height: 36px;
  }

  .logo-icon svg {
    width: 20px;
    height: 20px;
  }

  .tab {
    padding: var(--sp-2) var(--sp-3);
    font-size: var(--text-xs);
  }

  .tab svg {
    width: 14px;
    height: 14px;
  }

  .card {
    padding: var(--sp-5);
  }

  .drop-zone {
    padding: var(--sp-8) var(--sp-4);
  }

  .code-display {
    padding: var(--sp-3);
  }

  .code-display span {
    font-size: var(--text-xl);
    letter-spacing: 0.1em;
  }

  .download-meta {
    flex-direction: column;
    gap: var(--sp-2);
  }
}