:root {
    --primary: #4F46E5;
    --primary-dark: #3730A3;
    --accent: #06B6D4;
    --bg: #0B0F19;
    --surface: #111827;
    --surface-2: #1F2937;
    --text: #F9FAFB;
    --muted: #9CA3AF;
    --border: #374151;
    --success: #10B981;
  }
  * { box-sizing: border-box; margin: 0; padding: 0; }
  body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
  }
  a { color: inherit; text-decoration: none; }
  .container { max-width: 1120px; margin: 0 auto; padding: 0 24px; }
  nav {
    position: sticky; top: 0; z-index: 100;
    background: rgba(11, 15, 25, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
  }
  .nav-inner {
    display: flex; align-items: center; justify-content: space-between;
    height: 72px;
  }
  .logo {
    font-weight: 800; font-size: 1.5rem; letter-spacing: -0.02em;
    background: linear-gradient(135deg, #A5B4FC, #22D3EE);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  }
  .nav-actions { display: flex; gap: 12px; align-items: center; }
  .btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 10px 18px; border-radius: 10px; font-weight: 600; font-size: 0.95rem;
    border: none; cursor: pointer; transition: all 0.2s;
  }
  .btn-ghost { background: transparent; color: var(--text); border: 1px solid var(--border); }
  .btn-ghost:hover { background: var(--surface-2); }
  .btn-primary { background: var(--primary); color: white; }
  .btn-primary:hover { background: var(--primary-dark); }
  .btn-lg { padding: 14px 28px; font-size: 1.05rem; border-radius: 12px; }
  .form-card .btn-lg { width: 100%; }
  .hero {
    padding: 80px 0 60px;
    /* max-width: 1100px; */
    background: radial-gradient(ellipse at top, rgba(79, 70, 229, 0.15), transparent 60%);
    background-image: url('./hero-1.jpg'); background-size: 70%; background-position: center; 
    background-repeat: no-repeat;
  }
  .hero-grid {
    display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center;
  }
  .hero h1 {
    font-size: clamp(2.4rem, 5vw, 3.6rem); font-weight: 800; line-height: 1.1;
    letter-spacing: -0.03em; margin-bottom: 16px;
  }
  .hero p.lead { font-size: 1.25rem; color: var(--muted); margin-bottom: 28px; max-width: 520px; }
  .hero-ctas { display: flex; gap: 12px; flex-wrap: wrap; }
  .hero-img {
    border-radius: 20px; overflow: hidden;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.5);
  }
  .hero-img img { width: 100%; display: block; }
  section { padding: 80px 0; }
  .section-title {
    font-size: 2.2rem; font-weight: 800; text-align: center; margin-bottom: 12px;
    letter-spacing: -0.02em;
  }
  .section-sub { text-align: center; color: var(--muted); max-width: 560px; margin: 0 auto 48px; }
  .features {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px;
  }
  .feature-card {
    background: var(--surface); border: 1px solid var(--border); border-radius: 16px;
    padding: 28px; transition: transform 0.2s, border-color 0.2s;
  }
  .feature-card:hover { transform: translateY(-4px); border-color: var(--primary); }
  .feature-icon {
    width: 48px; height: 48px; border-radius: 12px;
    background: rgba(79, 70, 229, 0.15); display: flex; align-items: center; justify-content: center;
    margin-bottom: 16px; font-size: 1.5rem;
  }
  .feature-card h3 { font-size: 1.15rem; margin-bottom: 8px; }
  .feature-card p { color: var(--muted); font-size: 0.95rem; }
  .pricing-toggle,
  .billing-toggle {
    display: flex; align-items: center; justify-content: center; gap: 16px; margin-bottom: 40px;
  }
  .billing-toggle { gap: 14px; margin-bottom: 32px; }
  .toggle {
    position: relative; width: 56px; height: 30px; background: var(--surface-2);
    border-radius: 15px; cursor: pointer; border: 1px solid var(--border);
  }
  .toggle.active { background: var(--primary); }
  .toggle-knob {
    position: absolute; top: 3px; left: 3px; width: 24px; height: 24px;
    background: white; border-radius: 50%; transition: transform 0.2s;
  }
  .toggle.active .toggle-knob { transform: translateX(26px); }
  .save-badge {
    background: var(--success); color: white; font-size: 0.75rem; font-weight: 700;
    padding: 4px 10px; border-radius: 20px;
  }
  .pricing-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 20px;
  }
  .price-card {
    background: var(--surface); border: 1px solid var(--border); border-radius: 16px;
    padding: 28px 24px; position: relative; display: flex; flex-direction: column;
  }
  .price-card.featured {
    border-color: var(--primary); box-shadow: 0 0 0 1px var(--primary), 0 20px 40px -10px rgba(79,70,229,0.3);
  }
  .price-card.featured::before {
    content: "Most Popular"; position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
    background: var(--primary); color: white; font-size: 0.75rem; font-weight: 700;
    padding: 4px 12px; border-radius: 20px;
  }
  .price-card .plan-name { font-weight: 700; font-size: 1.1rem; margin-bottom: 4px; }
  .price-card .plan-price { font-size: 2.4rem; font-weight: 800; margin: 12px 0 4px; }
  .price-card .plan-price span { font-size: 1rem; font-weight: 500; color: var(--muted); }
  .plan-period { color: var(--muted); font-size: 0.9rem; margin-bottom: 20px; }
  .plan-features { list-style: none; flex: 1; margin-bottom: 24px; }
  .plan-features li {
    padding: 8px 0; color: var(--muted); font-size: 0.92rem;
    display: flex; align-items: flex-start; gap: 8px;
  }
  .plan-features li::before { content: "✓"; color: var(--success); font-weight: 700; }

  /* Signup page — selectable plan cards + account form */
  main { padding: 48px 0 80px; }
  .page-header { text-align: center; margin-bottom: 40px; }
  .page-header h1 {
    font-size: clamp(2rem, 4vw, 2.6rem); font-weight: 800; letter-spacing: -0.03em;
    margin-bottom: 8px;
  }
  .page-header p { color: var(--muted); font-size: 1.05rem; }
  .plans {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px;
    margin-bottom: 40px;
  }
  .plan {
    background: var(--surface); border: 2px solid var(--border); border-radius: 14px;
    padding: 20px 18px; cursor: pointer; transition: all 0.2s; position: relative;
  }
  .plan:hover { border-color: #4B5563; }
  .plan.selected {
    border-color: var(--primary);
    box-shadow: 0 0 0 1px var(--primary);
  }
  .plan.featured::after {
    content: "Popular";
    position: absolute; top: -10px; right: 12px;
    background: var(--primary); color: white; font-size: 0.7rem; font-weight: 700;
    padding: 2px 8px; border-radius: 12px;
  }
  .plan .plan-name { font-weight: 700; font-size: 1.05rem; }
  .plan .plan-price { font-size: 1.6rem; font-weight: 800; margin: 6px 0 2px; }
  .plan .plan-price span { font-size: 0.85rem; font-weight: 500; color: var(--muted); }
  .plan-detail { color: var(--muted); font-size: 0.85rem; margin-top: 4px; }
  .form-card {
    background: var(--surface); border: 1px solid var(--border); border-radius: 16px;
    padding: 32px; max-width: 480px; margin: 0 auto;
  }
  .form-card h2 { font-size: 1.25rem; margin-bottom: 20px; text-align: center; }
  .field { margin-bottom: 16px; }
  .field label { display: block; font-size: 0.9rem; font-weight: 500; margin-bottom: 6px; }
  .field input {
    width: 100%; padding: 12px 14px; border-radius: 10px; border: 1px solid var(--border);
    background: var(--bg); color: var(--text); font-size: 1rem; font-family: inherit;
  }
  .field input:focus { outline: none; border-color: var(--primary); }
  .selected-plan-summary {
    background: var(--surface-2); border-radius: 10px; padding: 12px 14px;
    margin-bottom: 20px; font-size: 0.9rem; text-align: center; color: var(--muted);
  }
  .selected-plan-summary strong { color: var(--text); }
  .form-footer {
    text-align: center; margin-top: 16px; font-size: 0.9rem; color: var(--muted);
  }
  .form-footer a { color: var(--accent); }
  #message {
    margin-top: 16px; text-align: center; font-size: 0.95rem; display: none;
  }
  #message.success { color: var(--success); }
  #message.error { color: #F87171; }
  .signup-section {
    background: var(--surface); border-radius: 24px; padding: 48px;
    border: 1px solid var(--border);
  }
  .signup-form { display: flex; flex-direction: column; gap: 16px; max-width: 480px; margin: 0 auto; position: relative; }
  .form-row { display: flex; gap: 12px; }
  input[type="text"], input[type="email"] {
    flex: 1; padding: 14px 16px; border-radius: 10px; border: 1px solid var(--border);
    background: var(--bg); color: var(--text); font-size: 1rem;
  }
  input:focus { outline: none; border-color: var(--primary); }
  .form-note { text-align: center; color: var(--muted); font-size: 0.85rem; margin: 0; }
  .form-note a { color: var(--text); text-decoration: underline; text-underline-offset: 2px; }
  .hp {
    position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden;
  }
  .success, .form-error {
    display: none; border-radius: 12px; padding: 18px; text-align: center;
  }
  .success {
    background: rgba(16, 185, 129, 0.12); border: 1px solid rgba(16, 185, 129, 0.35); color: var(--text);
  }
  .success p { margin: 0 0 14px; }
  .form-error {
    background: rgba(239, 68, 68, 0.12); border: 1px solid rgba(239, 68, 68, 0.4); color: #FCA5A5;
  }
  .success.show, .form-error.show { display: block; }
  .btn:disabled { opacity: 0.65; cursor: wait; }
  .signup-form.is-done .form-row,
  .signup-form.is-done .btn-lg,
  .signup-form.is-done .form-note,
  .signup-form.is-done .hp { display: none; }
  footer {
    padding: 40px 0; border-top: 1px solid var(--border); text-align: center; color: var(--muted); font-size: 0.9rem;
  }
  footer a { color: var(--text); text-decoration: underline; text-underline-offset: 2px; }
  @media (max-width: 1140px) {
    .hero {
        background-image: url('./hero-1.jpg'); 
        background-size: cover; background-position: center; 
        background-repeat: no-repeat;
      }
  }
  @media (max-width: 768px) {
    .hero { background: radial-gradient(ellipse at top, rgba(79, 70, 229, 0.15), transparent 60%); }
    .hero-grid { grid-template-columns: 1fr; text-align: center; }
    .hero p.lead { margin-left: auto; margin-right: auto; text-shadow: 1px 1px 4px rgba(0, 0, 0, 1);}
    .hero-ctas { justify-content: center; }
    .form-row { flex-direction: column; }
    .signup-section { padding: 32px 20px; }
  }
  @media (max-width: 640px) {
    .form-card { padding: 24px 18px; }
    .plans { grid-template-columns: 1fr 1fr; }
  }