/* CSS Design System for Huaguang Yuanhai Survey */
:root {
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  
  /* Color Palette - Executive Slate & Tech Sapphire */
  --bg-color: #F8FAFC;
  --card-bg: #FFFFFF;
  --text-main: #0F172A;
  --text-muted: #475569;
  --text-light: #94A3B8;
  
  --primary-color: #1E3A8A; /* Navy Blue */
  --primary-hover: #1E40AF;
  --accent-blue: #2563EB;
  --accent-teal: #0D9488;
  --border-color: #E2E8F0;
  --border-active: #3B82F6;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
}

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

body {
  font-family: var(--font-primary);
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
  padding: 24px 16px 60px 16px;
  min-height: 100vh;
}

.app-container {
  max-width: 820px;
  margin: 0 auto;
}

/* Header */
.header {
  background: linear-gradient(135deg, #0F172A 0%, #1E3A8A 100%);
  color: #FFFFFF;
  padding: 36px 32px 32px 32px;
  border-radius: var(--radius-lg);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.badge {
  display: inline-block;
  background-color: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(8px);
  color: #93C5FD;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 20px;
  letter-spacing: 0.5px;
  margin-bottom: 12px;
}

.header h1 {
  font-size: 1.65rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
  line-height: 1.3;
}

.subtitle {
  color: #CBD5E1;
  font-size: 0.875rem;
  font-weight: 400;
}

.progress-bar-container {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 5px;
  background-color: rgba(255, 255, 255, 0.1);
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #38BDF8 0%, #818CF8 100%);
  transition: width 0.3s ease;
}

/* Intro Card */
.intro-card {
  background-color: #EFF6FF;
  border: 1px solid #BFDBFE;
  padding: 20px 24px;
  border-radius: var(--radius-md);
  margin-top: 20px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.intro-icon {
  font-size: 1.8rem;
}

.intro-text h3 {
  font-size: 0.95rem;
  font-weight: 600;
  color: #1E40AF;
  margin-bottom: 4px;
}

.intro-text p {
  font-size: 0.875rem;
  color: #1E3A8A;
}

/* Form Sections */
.form-section {
  background-color: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  margin-top: 24px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.section-tag {
  color: var(--accent-blue);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 1px;
  margin-bottom: 4px;
}

.section-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid #F1F5F9;
}

/* Question Cards */
.question-card {
  margin-bottom: 28px;
}

.question-card:last-child {
  margin-bottom: 0;
}

.question-label {
  display: block;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 12px;
}

.q-num {
  color: var(--accent-blue);
  margin-right: 6px;
}

.required {
  color: #EF4444;
}

.sub-hint {
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--text-muted);
}

/* Options Grid */
.options-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.options-grid.horizontal {
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}

.option-item {
  display: flex;
  align-items: center;
  gap: 12px;
  background-color: #F8FAFC;
  border: 1.5px solid var(--border-color);
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 0.875rem;
  color: var(--text-main);
}

.option-item:hover {
  background-color: #F1F5F9;
  border-color: #CBD5E1;
}

.option-item input[type="radio"],
.option-item input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--accent-blue);
  cursor: pointer;
}

.option-item:has(input:checked) {
  background-color: #EFF6FF;
  border-color: var(--border-active);
  font-weight: 500;
}

/* Inputs & Textareas */
.sub-input-box {
  margin-top: 12px;
}

.sub-input-box label {
  display: block;
  font-size: 0.825rem;
  color: var(--text-muted);
  margin-bottom: 6px;
}

input[type="text"], textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.875rem;
  color: var(--text-main);
  background-color: #FFFFFF;
  transition: border-color 0.2s ease;
}

input[type="text"]:focus, textarea:focus {
  outline: none;
  border-color: var(--border-active);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

/* Submit Container */
.submit-container {
  margin-top: 36px;
  text-align: center;
}

.submit-btn {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-blue) 100%);
  color: #FFFFFF;
  font-size: 1.05rem;
  font-weight: 600;
  padding: 16px 48px;
  border: none;
  border-radius: 30px;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  transition: all 0.25s ease;
}

.submit-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  opacity: 0.95;
}

/* Result Modal */
.result-modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
  z-index: 999;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.result-card {
  background-color: #FFFFFF;
  border-radius: var(--radius-lg);
  max-width: 680px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  padding: 32px;
  box-shadow: var(--shadow-lg);
}

.success-icon {
  font-size: 2.5rem;
  text-align: center;
  margin-bottom: 8px;
}

.result-card h2 {
  font-size: 1.35rem;
  text-align: center;
  color: var(--text-main);
  margin-bottom: 8px;
}

.result-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 20px;
}

.report-box {
  background-color: #F8FAFC;
  border: 1px solid var(--border-color);
  padding: 20px;
  border-radius: var(--radius-md);
  font-family: monospace;
  font-size: 0.825rem;
  color: #334155;
  white-space: pre-wrap;
  max-height: 300px;
  overflow-y: auto;
  margin-bottom: 24px;
}

.btn-group {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.action-btn {
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all 0.2s ease;
}

.action-btn.primary {
  background-color: var(--accent-blue);
  color: #FFFFFF;
}

.action-btn.primary:hover {
  background-color: var(--primary-hover);
}

.action-btn.secondary {
  background-color: #E2E8F0;
  color: var(--text-main);
}

.action-btn.secondary:hover {
  background-color: #CBD5E1;
}

/* Footer */
.footer {
  margin-top: 40px;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-light);
}

@media (max-width: 640px) {
  .header {
    padding: 24px 20px;
  }
  .form-section {
    padding: 20px 16px;
  }
  .options-grid.horizontal {
    grid-template-columns: 1fr;
  }
  .btn-group {
    flex-direction: column;
  }
}