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

:root {
  --color-bg: #f5f5f5;
  --color-surface: #ffffff;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-border: #e2e8f0;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-success: #16a34a;
  --color-error: #dc2626;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  line-height: 1.5;
}

.card {
  background: var(--color-surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 2rem;
  width: 100%;
  max-width: 480px;
}

h1 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  color: var(--color-text);
}

.step {
  display: none;
}
.step.active {
  display: block;
}

.form-group {
  margin-bottom: 1rem;
}

label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.375rem;
  color: var(--color-text);
}

input[type="email"],
input[type="text"],
input[type="number"] {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 1rem;
  color: var(--color-text);
  outline: none;
  transition: border-color 0.15s;
}
input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

button {
  width: 100%;
  padding: 0.625rem 1rem;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s;
  margin-top: 0.5rem;
}
button:hover:not(:disabled) {
  background: var(--color-primary-hover);
}
button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}
.btn-secondary:hover:not(:disabled) {
  background: rgba(37, 99, 235, 0.05);
}

.drop-zone {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
  padding: 2.5rem 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
  margin-bottom: 1rem;
}
.drop-zone.drag-over {
  border-color: var(--color-primary);
  background: rgba(37, 99, 235, 0.04);
}
.drop-zone p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin-top: 0.5rem;
}
.drop-zone-icon {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.file-info {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  background: var(--color-bg);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  margin-bottom: 1rem;
  word-break: break-all;
}
.file-info strong {
  color: var(--color-text);
}

.progress-wrap {
  margin: 1rem 0;
  display: none;
}
.progress-wrap.visible {
  display: block;
}
.progress-label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 0.375rem;
  display: flex;
  justify-content: space-between;
}
.progress-bar-bg {
  background: var(--color-border);
  border-radius: 999px;
  height: 6px;
  overflow: hidden;
}
.progress-bar {
  background: var(--color-primary);
  height: 100%;
  border-radius: 999px;
  width: 0%;
  transition: width 0.2s;
}
.progress-detail {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: 0.35rem;
}

.message {
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  font-size: 0.9rem;
  margin-bottom: 1rem;
  display: none;
}
.message.visible {
  display: block;
}
.message.error {
  background: #fef2f2;
  color: var(--color-error);
  border: 1px solid #fecaca;
}
.message.success {
  background: #f0fdf4;
  color: var(--color-success);
  border: 1px solid #bbf7d0;
}

.resend-link {
  text-align: center;
  margin-top: 0.75rem;
  font-size: 0.85rem;
}
.resend-link a {
  color: var(--color-primary);
  cursor: pointer;
  text-decoration: underline;
}

@media (max-width: 480px) {
  .card {
    padding: 1.5rem 1rem;
  }
}