:root {
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --secondary: #a855f7;
  --bg: #0f172a;
  --card-bg: rgba(30, 41, 59, 0.7);
  --text: #f8fafc;
  --text-muted: #94a3b8;
  --border: rgba(255, 255, 255, 0.1);
  --glass: rgba(255, 255, 255, 0.05);
  --radius: 16px;
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-main);
  line-height: 1.6;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 0% 0%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
    radial-gradient(circle at 100% 100%, rgba(168, 85, 247, 0.15) 0%, transparent 50%);
  background-attachment: fixed;
}

.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 20px;
}

/* Header & Hero */
header {
  padding: 40px 0 20px;
  text-align: center;
}

h1 {
  font-size: 2.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, #fff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 10px;
}

.subtitle {
  color: var(--text-muted);
  font-size: 1.1rem;
}

/* Client Cards */
.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 32px;
}

@media (min-width: 480px) {
  .grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.card {
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 20px;
  position: relative;
  overflow: hidden;
}

.card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  opacity: 0;
  transition: opacity 0.3s;
  z-index: -1;
}

.card:hover {
  transform: translateY(-5px);
  border-color: rgba(99, 102, 241, 0.5);
  box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
}

.card-icon {
  width: 60px;
  height: 60px;
  background: var(--glass);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

.card-info h3 {
  font-size: 1.25rem;
  margin-bottom: 4px;
}

.card-info p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Tutorial Section */
.tutorial-view {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg);
  z-index: 100;
  overflow-y: auto;
  display: none;
  animation: slideUp 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes slideUp {
  from { transform: translateY(100%); }
  to { transform: translateY(0); }
}

.top-bar {
  position: sticky;
  top: 0;
  background: rgba(15, 23, 42, 0.8);
  backdrop-filter: blur(12px);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  z-index: 10;
}

.btn-back {
  background: var(--glass);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 0.9rem;
  cursor: pointer;
}

/* Step Content */
.step {
  margin-bottom: 40px;
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 20px;
  border: 1px solid var(--border);
}

.step-num {
  display: inline-block;
  padding: 4px 12px;
  background: var(--primary);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.step h4 {
  font-size: 1.2rem;
  margin-bottom: 12px;
}

.step p {
  color: var(--text-muted);
  margin-bottom: 16px;
}

.step-img {
  width: 100%;
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.download-box {
  margin-top: 20px;
  background: rgba(99, 102, 241, 0.1);
  border: 1px dashed var(--primary);
  padding: 16px;
  border-radius: 12px;
  text-align: center;
}

.btn-download {
  display: inline-block;
  margin-top: 10px;
  background: var(--primary);
  color: white;
  text-decoration: none;
  padding: 10px 24px;
  border-radius: 24px;
  font-weight: 600;
  transition: background 0.3s;
}

.btn-download:hover {
  background: var(--primary-dark);
}

.caution {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
  padding: 16px;
  border-radius: 12px;
  margin-bottom: 24px;
  color: #fca5a5;
  display: flex;
  gap: 12px;
}

.security-alert {
  background: rgba(245, 158, 11, 0.15);
  border-left: 4px solid #f59e0b;
  padding: 16px;
  margin: 16px 0;
  border-radius: 4px 12px 12px 4px;
}

.security-alert strong {
  color: #fbbf24;
  display: block;
  margin-bottom: 4px;
}

.account-center {
  background: var(--glass);
  border: 1px solid var(--border);
  padding: 16px;
  border-radius: 12px;
  margin: 16px 0;
}

.account-center ul {
  list-style: none;
  margin-top: 12px;
}

.account-center li {
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.account-center li::before {
  content: '🔗';
  font-size: 0.8rem;
}

.step-list {
  margin-top: 12px;
  counter-reset: step-counter;
}

.step-item {
  position: relative;
  padding-left: 36px;
  margin-bottom: 12px;
}

.step-item::before {
  counter-increment: step-counter;
  content: counter(step-counter);
  position: absolute;
  left: 0;
  top: 0;
  width: 24px;
  height: 24px;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: bold;
}

.caution-icon {
  flex-shrink: 0;
  font-weight: bold;
}

/* Footer */
footer {
  text-align: center;
  padding: 60px 0 40px;
  color: var(--text-muted);
  font-size: 0.85rem;
}