/* ========== Site 4: Professional Purple Theme ========== */
:root {
  --primary: #7c3aed;
  --primary-dark: #5b21b6;
  --primary-light: #f5f3ff;
  --accent: #0ea5e9;
  --text: #0f172a;
  --text-secondary: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-lg: 0 20px 50px rgba(124,58,237,0.12);
}

@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; color: var(--text); background: var(--bg); line-height: 1.6; }

/* Header */
.header { background: var(--bg); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; }
.nav { max-width: 1200px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; padding: 0 28px; height: 66px; }
.logo { display: flex; align-items: center; gap: 10px; font-size: 20px; font-weight: 700; color: var(--primary); text-decoration: none; }
.logo svg { width: 32px; height: 32px; }
.nav-links { display: flex; gap: 8px; list-style: none; }
.nav-links a { display: block; padding: 8px 20px; border-radius: 20px; color: var(--text-secondary); text-decoration: none; font-size: 14px; font-weight: 500; transition: all 0.2s; }
.nav-links a:hover { color: var(--primary); background: var(--primary-light); }
.nav-links a.active { color: #fff; background: linear-gradient(135deg, var(--primary-dark), var(--primary)); }

/* Hero - gradient text */
.hero { background: linear-gradient(160deg, #1e1b4b 0%, #312e81 30%, #7c3aed 70%, #a78bfa 100%); color: #fff; padding: 90px 28px; text-align: center; }
.hero h1 { font-size: 46px; font-weight: 800; margin-bottom: 18px; letter-spacing: -0.5px; background: linear-gradient(to right, #fff, #c4b5fd); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero p { font-size: 19px; opacity: 0.88; max-width: 620px; margin: 0 auto 36px; line-height: 1.7; }

.btn { display: inline-flex; align-items: center; gap: 8px; padding: 14px 36px; border-radius: 28px; font-size: 16px; font-weight: 600; border: none; cursor: pointer; transition: all 0.25s; text-decoration: none; }
.btn-primary { background: linear-gradient(135deg, #a78bfa, #7c3aed); color: #fff; box-shadow: 0 4px 20px rgba(124,58,237,0.4); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(124,58,237,0.5); }
.btn-secondary { background: rgba(255,255,255,0.1); color: #fff; border: 1px solid rgba(255,255,255,0.25); }
.btn-secondary:hover { background: rgba(255,255,255,0.2); }
.btn-small { padding: 10px 24px; font-size: 14px; }

/* Sections */
.section { max-width: 1200px; margin: 0 auto; padding: 80px 28px; }
.section-alt { background: var(--bg-alt); }
.section-title { font-size: 36px; font-weight: 800; text-align: center; margin-bottom: 12px; }
.section-subtitle { font-size: 17px; color: var(--text-secondary); text-align: center; margin-bottom: 48px; }

/* Features - horizontal cards */
.features-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.feature-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; display: flex; gap: 20px; align-items: flex-start; transition: all 0.25s; }
.feature-card:hover { box-shadow: var(--shadow-lg); border-color: var(--primary); }
.feature-icon { width: 48px; height: 48px; flex-shrink: 0; color: var(--primary); background: var(--primary-light); padding: 10px; border-radius: 10px; }
.feature-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.feature-card p { color: var(--text-secondary); font-size: 14px; line-height: 1.7; }

/* Platforms - 4 columns */
.platform-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.platform-card { background: var(--bg); border-radius: var(--radius); padding: 28px 20px; text-align: center; border: 1px solid var(--border); transition: all 0.25s; }
.platform-card:hover { border-color: var(--primary); box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.platform-icon { width: 44px; height: 44px; margin-bottom: 12px; }
.platform-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.platform-card p { font-size: 13px; color: var(--text-secondary); margin-bottom: 14px; }

/* Details - numbered */
.detail-block { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; margin-bottom: 60px; }
.detail-block:nth-child(even) { direction: rtl; }
.detail-block:nth-child(even) > * { direction: ltr; }
.detail-block h3 { font-size: 28px; font-weight: 800; margin-bottom: 16px; color: var(--primary-dark); }
.detail-block p { color: var(--text-secondary); font-size: 15px; line-height: 1.8; margin-bottom: 10px; }
.detail-visual { background: linear-gradient(135deg, var(--primary-light), #ede9fe); border-radius: var(--radius); height: 260px; display: flex; align-items: center; justify-content: center; }

/* Reviews - card style */
.review-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.review-card { background: var(--bg); border-radius: var(--radius); padding: 28px; border: 1px solid var(--border); box-shadow: var(--shadow); }
.review-stars { color: #f59e0b; margin-bottom: 12px; }
.review-text { font-size: 15px; color: var(--text); margin-bottom: 16px; line-height: 1.7; }
.review-author { font-weight: 600; font-size: 14px; color: var(--text-secondary); }

/* Stats */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; text-align: center; }
.stat-item { background: linear-gradient(135deg, var(--primary-dark), var(--primary)); color: #fff; padding: 32px 20px; border-radius: var(--radius); }
.stat-item h4 { font-size: 36px; font-weight: 800; margin-bottom: 6px; }
.stat-item p { font-size: 14px; opacity: 0.85; }

/* Comparison */
.compare-table { width: 100%; border-collapse: collapse; background: var(--bg); border-radius: var(--radius); overflow: hidden; border: 1px solid var(--border); }
.compare-table th { background: linear-gradient(135deg, var(--primary-dark), var(--primary)); color: #fff; padding: 16px 24px; text-align: left; font-weight: 600; }
.compare-table td { padding: 16px 24px; border-bottom: 1px solid var(--border); }
.compare-table tr:last-child td { border-bottom: none; }
.check { color: var(--primary); font-weight: 700; }

/* FAQ */
.faq-item { border-bottom: 1px solid var(--border); }
.faq-question { display: flex; justify-content: space-between; align-items: center; padding: 22px 0; cursor: pointer; font-size: 17px; font-weight: 600; }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; }
.faq-answer-inner { padding-bottom: 22px; color: var(--text-secondary); line-height: 1.8; }
.faq-item:target .faq-answer, .faq-item.active .faq-answer { max-height: 500px; }
.faq-toggle { width: 22px; height: 22px; color: var(--primary); transition: transform 0.3s; }
.faq-item.active .faq-toggle { transform: rotate(180deg); }

/* CTA */
.cta-section { background: linear-gradient(135deg, #1e1b4b, #7c3aed); padding: 80px 28px; text-align: center; }
.cta-section h2 { color: #fff; font-size: 36px; font-weight: 800; margin-bottom: 16px; }
.cta-section p { color: rgba(255,255,255,0.88); font-size: 18px; margin-bottom: 32px; }

/* Download page */
.dl-hero { background: linear-gradient(160deg, #1e1b4b 0%, #312e81 30%, #7c3aed 70%, #a78bfa 100%); color: #fff; padding: 60px 28px; text-align: center; }
.dl-hero h1 { font-size: 40px; font-weight: 800; margin-bottom: 12px; }
.dl-meta { display: inline-flex; gap: 20px; margin: 16px 0 28px; font-size: 14px; opacity: 0.88; flex-wrap: wrap; justify-content: center; }
.dl-meta span { background: rgba(255,255,255,0.12); padding: 6px 16px; border-radius: 20px; }
.dl-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.dl-card { background: var(--bg); border-radius: var(--radius); padding: 32px; border: 1px solid var(--border); }
.dl-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 12px; display: flex; align-items: center; gap: 10px; }
.dl-card p { color: var(--text-secondary); font-size: 14px; margin-bottom: 16px; }
.sys-req { background: var(--bg-alt); padding: 16px; border-radius: var(--radius); margin-top: 16px; }
.sys-req h4 { font-size: 14px; font-weight: 700; margin-bottom: 10px; }
.sys-req ul { list-style: none; font-size: 13px; color: var(--text-secondary); }
.sys-req li { padding: 3px 0; }

.steps { max-width: 700px; }
.step { display: flex; gap: 20px; margin-bottom: 24px; }
.step-num { width: 40px; height: 40px; background: linear-gradient(135deg, var(--primary-dark), var(--primary)); color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 700; flex-shrink: 0; }
.step-content h4 { font-size: 17px; font-weight: 700; margin-bottom: 6px; }
.step-content p { color: var(--text-secondary); font-size: 14px; line-height: 1.7; }

.changelog-item { padding: 20px 0; border-bottom: 1px solid var(--border); }
.changelog-item:last-child { border-bottom: none; }
.changelog-header { display: flex; gap: 16px; margin-bottom: 10px; }
.changelog-version { background: linear-gradient(135deg, var(--primary-dark), var(--primary)); color: #fff; padding: 4px 14px; border-radius: 20px; font-size: 13px; font-weight: 600; }
.changelog-date { color: var(--text-secondary); font-size: 14px; }
.changelog-item ul { margin-left: 20px; color: var(--text-secondary); font-size: 14px; }
.changelog-item li { margin-bottom: 4px; }

/* Footer */
.footer { background: #0f172a; color: #fff; padding: 40px 28px; text-align: center; }
.footer p { opacity: 0.65; font-size: 14px; line-height: 1.8; }

@media (max-width: 768px) {
  .hero h1 { font-size: 30px; }
  .features-grid { grid-template-columns: 1fr; }
  .platform-grid { grid-template-columns: repeat(2, 1fr); }
  .detail-block { grid-template-columns: 1fr; }
  .review-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .dl-grid { grid-template-columns: 1fr; }
  .nav-links a { padding: 6px 14px; font-size: 13px; }
}