/* Ventoy Website Styles */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  --secondary: #0ea5e9;
  --accent: #f59e0b;
  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  --dark: #0f172a;
  --dark-light: #1e293b;
  --gray: #64748b;
  --gray-light: #94a3b8;
  --gray-lighter: #e2e8f0;
  --light: #f8fafc;
  --white: #ffffff;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --radius: 8px;
  --radius-lg: 16px;
  --transition: all 0.3s ease;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  color: var(--dark);
  background: var(--white);
  overflow-x: hidden;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--primary-dark);
}

img {
  max-width: 100%;
  height: auto;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  border-bottom: 1px solid var(--gray-lighter);
  transition: var(--transition);
}

.header.scrolled {
  box-shadow: var(--shadow);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-dark);
}

.logo img {
  width: 40px;
  height: 40px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 30px;
}

.nav a {
  color: var(--dark);
  font-weight: 500;
  font-size: 0.95rem;
  position: relative;
}

.nav a:hover,
.nav a.active {
  color: var(--primary);
}

.nav a.active::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 5px;
}

.nav-toggle span {
  width: 25px;
  height: 3px;
  background: var(--dark);
  border-radius: 3px;
  transition: var(--transition);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: var(--white);
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
  color: var(--white);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: var(--white);
  transform: translateY(-2px);
}

.btn-success {
  background: linear-gradient(135deg, var(--success), #059669);
  color: var(--white);
  box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.btn-success:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
  color: var(--white);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.1rem;
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #0f172a 100%);
  color: var(--white);
  padding: 160px 0 100px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content h1 {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
}

.hero-content h1 span {
  background: linear-gradient(135deg, var(--primary-light), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-content .subtitle {
  font-size: 1.2rem;
  color: var(--gray-light);
  margin-bottom: 30px;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 15px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.hero-stats {
  display: flex;
  gap: 40px;
}

.hero-stat {
  text-align: center;
}

.hero-stat .number {
  font-size: 2rem;
  font-weight: 800;
  color: var(--secondary);
}

.hero-stat .label {
  font-size: 0.85rem;
  color: var(--gray-light);
}

.hero-image {
  position: relative;
}

.hero-image img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  border: 2px solid rgba(255, 255, 255, 0.1);
}

.hero-image .floating-img {
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-20px); }
}

/* Section */
.section {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 15px;
  color: var(--dark);
}

.section-header p {
  font-size: 1.1rem;
  color: var(--gray);
  max-width: 600px;
  margin: 0 auto;
}

.section-header .badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(37, 99, 235, 0.1);
  color: var(--primary);
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 15px;
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.feature-card {
  background: var(--white);
  border: 1px solid var(--gray-lighter);
  border-radius: var(--radius-lg);
  padding: 40px 30px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  transform: scaleX(0);
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.feature-card:hover::before {
  transform: scaleX(1);
}

.feature-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.1), rgba(14, 165, 233, 0.1));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.8rem;
}

.feature-card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--dark);
}

.feature-card p {
  color: var(--gray);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* Screenshots Section */
.screenshots-section {
  background: var(--light);
}

.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 25px;
}

.screenshot-card {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  background: var(--white);
}

.screenshot-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

.screenshot-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.screenshot-card .caption {
  padding: 15px 20px;
  font-weight: 500;
  color: var(--dark);
  font-size: 0.9rem;
}

/* How To Section */
.howto-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 30px;
  position: relative;
}

.howto-step {
  text-align: center;
  position: relative;
}

.howto-step::after {
  content: '';
  position: absolute;
  top: 40px;
  right: -15px;
  width: 30px;
  height: 2px;
  background: var(--gray-lighter);
}

.howto-step:last-child::after {
  display: none;
}

.step-number {
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 2rem;
  font-weight: 700;
  margin: 0 auto 20px;
  box-shadow: 0 4px 20px rgba(37, 99, 235, 0.3);
}

.howto-step h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.howto-step p {
  color: var(--gray);
  font-size: 0.9rem;
}

/* Supported OS */
.os-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  justify-content: center;
}

.os-tag {
  padding: 10px 20px;
  background: var(--white);
  border: 1px solid var(--gray-lighter);
  border-radius: 30px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--dark);
  transition: var(--transition);
}

.os-tag:hover {
  background: var(--primary);
  color: var(--white);
  border-color: var(--primary);
  transform: scale(1.05);
}

/* Download CTA */
.download-cta {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: var(--white);
  padding: 80px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.download-cta::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 40%;
  height: 200%;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 50%;
  transform: rotate(-15deg);
}

.download-cta h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 15px;
}

.download-cta p {
  font-size: 1.1rem;
  opacity: 0.8;
  margin-bottom: 30px;
}

.download-cta .btn {
  background: var(--white);
  color: var(--primary);
}

.download-cta .btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* FAQ Section */
.faq-section {
  background: var(--light);
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--white);
  border: 1px solid var(--gray-lighter);
  border-radius: var(--radius);
  margin-bottom: 15px;
  overflow: hidden;
}

.faq-question {
  padding: 20px 25px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  transition: var(--transition);
}

.faq-question:hover {
  background: var(--light);
}

.faq-question .icon {
  width: 24px;
  height: 24px;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.faq-item.active .faq-question .icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

.faq-answer .content {
  padding: 0 25px 20px;
  color: var(--gray);
  line-height: 1.7;
}

/* Page Layout */
.page-header {
  background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #0f172a 100%);
  color: var(--white);
  padding: 140px 0 60px;
  text-align: center;
}

.page-header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 15px;
}

.page-header p {
  font-size: 1.1rem;
  color: var(--gray-light);
  max-width: 600px;
  margin: 0 auto;
}

.page-content {
  padding: 60px 0;
}

.page-content h2 {
  font-size: 1.8rem;
  margin-bottom: 20px;
  margin-top: 40px;
}

.page-content h3 {
  font-size: 1.3rem;
  margin-bottom: 15px;
  margin-top: 30px;
}

.page-content p {
  color: var(--gray);
  line-height: 1.8;
  margin-bottom: 15px;
}

.page-content ul,
.page-content ol {
  color: var(--gray);
  margin-bottom: 20px;
  padding-left: 25px;
}

.page-content li {
  margin-bottom: 8px;
  line-height: 1.7;
}

/* Download Cards */
.download-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
  margin-top: 30px;
}

.download-card {
  background: var(--white);
  border: 1px solid var(--gray-lighter);
  border-radius: var(--radius-lg);
  padding: 35px;
  transition: var(--transition);
}

.download-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.download-card h3 {
  font-size: 1.3rem;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.download-card .version {
  font-size: 0.85rem;
  color: var(--gray);
  margin-bottom: 15px;
}

.download-card .dl-files {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 15px;
}

.dl-link {
  padding: 8px 16px;
  background: var(--light);
  border: 1px solid var(--gray-lighter);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--dark);
  transition: var(--transition);
}

/* Download Buttons */
.dl-files {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 15px;
}
.dl-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all 0.3s ease;
  font-family: inherit;
}
.dl-btn-quark {
  background: linear-gradient(135deg, #4f8cff, #1a6dff);
  color: #fff;
  box-shadow: 0 4px 15px rgba(79, 140, 255, 0.3);
}
.dl-btn-quark:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(79, 140, 255, 0.5);
}
.dl-btn-baidu {
  background: linear-gradient(135deg, #ff5722, #d84315);
  color: #fff;
  box-shadow: 0 4px 15px rgba(255, 87, 34, 0.3);
}
.dl-btn-baidu:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 87, 34, 0.5);
}

/* ========== 弹窗蒙层 ========== */
.qr-modal-mask {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.65);
  z-index: 10000;
  display: none;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.25s ease;
}
.qr-modal-mask.show {
  display: flex;
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
.qr-modal {
  background: #fff;
  border-radius: 16px;
  max-width: 480px;
  width: 92%;
  padding: 0;
  box-shadow: 0 25px 60px rgba(0,0,0,0.3);
  animation: slideUp 0.3s ease;
  overflow: hidden;
}
@keyframes slideUp {
  from { transform: translateY(30px); opacity: 0; }
  to   { transform: translateY(0); opacity: 1; }
}
.qr-modal-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  background: linear-gradient(135deg, #2563eb, #0ea5e9);
  color: #fff;
}
.qr-modal-head h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0;
}
.qr-modal-close {
  background: none;
  border: none;
  color: #fff;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0 4px;
  line-height: 1;
  transition: transform 0.2s;
}
.qr-modal-close:hover {
  transform: rotate(90deg);
}
.qr-modal-body {
  padding: 28px 24px 24px;
  text-align: center;
}

/* ========== 二维码柔和呼吸边框动画 ========== */
.qr-code-wrap {
  display: inline-block;
  padding: 12px;
  border-radius: 16px;
  border: 3px solid rgba(60,235,126,0.45);
  position: relative;
  margin-bottom: 16px;
  animation: qrBreath 3.5s ease-in-out infinite;
}
@keyframes qrBreath {
  0%, 100% {
    border-color: rgba(60,235,126,0.45);
    box-shadow: 0 0 10px rgba(60,235,126,0.12);
    transform: scale(0.98);
  }
  50% {
    border-color: rgba(77,168,255,0.45);
    box-shadow: 0 0 10px rgba(77,168,255,0.12);
    transform: scale(1.01);
  }
}
.qr-code-wrap-baidu { animation-name: qrBreathBaidu; border-color: rgba(255,87,34,0.45); }
@keyframes qrBreathBaidu {
  0%, 100% {
    border-color: rgba(255,87,34,0.45);
    box-shadow: 0 0 10px rgba(255,87,34,0.12);
    transform: scale(0.98);
  }
  50% {
    border-color: rgba(255,140,50,0.45);
    box-shadow: 0 0 10px rgba(255,140,50,0.12);
    transform: scale(1.01);
  }
}
.qr-code-wrap img {
  display: block;
  width: 180px;
  height: 180px;
  border-radius: 8px;
}

/* ========== 弹窗文案 ========== */
.qr-modal-desc { text-align: left; margin-bottom: 16px; }
.qr-modal-desc h4 { font-size: 1rem; font-weight: 700; margin-bottom: 12px; color: #1e293b; }
.qr-modal-desc ul { list-style: none; padding: 0; margin: 0; }
.qr-modal-desc li { position: relative; padding-left: 28px; margin-bottom: 8px; font-size: 0.88rem; color: #475569; line-height: 1.6; }
.qr-modal-desc li::before {
  content: '✓';
  position: absolute;
  left: 0; top: 0;
  width: 20px; height: 20px;
  background: #10b981;
  color: #fff;
  border-radius: 50%;
  font-size: 0.7rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}
.qr-modal-tip {
  background: linear-gradient(135deg, #fff8e1, #fff3cd);
  border: 1px solid #f59e0b;
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 0.82rem;
  color: #92400e;
  text-align: left;
  display: flex;
  align-items: flex-start;
  gap: 8px;
}
.qr-modal-tip .icon { flex-shrink: 0; font-size: 1rem; }

/* Tutorial Steps */
.tutorial-steps {
  max-width: 800px;
  margin: 0 auto;
}

.tutorial-step {
  display: flex;
  gap: 30px;
  margin-bottom: 50px;
  align-items: flex-start;
}

.tutorial-step .step-num {
  flex-shrink: 0;
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 1.5rem;
  font-weight: 700;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.tutorial-step .step-content {
  flex: 1;
}

.tutorial-step .step-content h3 {
  margin-bottom: 10px;
  font-size: 1.3rem;
}

.tutorial-step .step-content p {
  color: var(--gray);
  line-height: 1.8;
}

/* Table */
.table-wrapper {
  overflow-x: auto;
  margin: 20px 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

table th {
  background: var(--primary);
  color: var(--white);
  padding: 15px 20px;
  text-align: left;
  font-weight: 600;
}

table td {
  padding: 12px 20px;
  border-bottom: 1px solid var(--gray-lighter);
}

table tr:last-child td {
  border-bottom: none;
}

table tr:hover td {
  background: var(--light);
}

/* Footer */
.footer {
  background: var(--dark);
  color: var(--white);
  padding: 60px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer h3 {
  font-size: 1.1rem;
  margin-bottom: 20px;
  color: var(--white);
}

.footer p {
  color: var(--gray-light);
  font-size: 0.9rem;
  line-height: 1.7;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: var(--gray-light);
  font-size: 0.9rem;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--primary-light);
}

.footer-bottom {
  border-top: 1px solid var(--dark-light);
  padding-top: 25px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-bottom p {
  color: var(--gray);
  font-size: 0.85rem;
}

.footer-bottom a {
  color: var(--gray-light);
}

.footer-bottom a:hover {
  color: var(--primary-light);
}

/* Code Block */
.code-block {
  background: var(--dark);
  color: var(--gray-lighter);
  padding: 20px 25px;
  border-radius: var(--radius);
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 0.9rem;
  overflow-x: auto;
  margin: 15px 0;
  line-height: 1.6;
}

/* Alert */
.alert {
  padding: 15px 20px;
  border-radius: var(--radius);
  margin: 20px 0;
  border-left: 4px solid;
}

.alert-info {
  background: rgba(37, 99, 235, 0.05);
  border-color: var(--primary);
  color: var(--primary-dark);
}

.alert-warning {
  background: rgba(245, 158, 11, 0.05);
  border-color: var(--warning);
  color: #b45309;
}

.alert-success {
  background: rgba(16, 185, 129, 0.05);
  border-color: var(--success);
  color: #047857;
}

/* Responsive */
@media (max-width: 992px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-content h1 {
    font-size: 2.5rem;
  }
  .hero-buttons {
    justify-content: center;
  }
  .hero-stats {
    justify-content: center;
  }
  .hero-image {
    order: -1;
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .screenshot-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .howto-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .howto-step::after {
    display: none;
  }
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 20px;
    gap: 15px;
    box-shadow: var(--shadow-lg);
    border-top: 1px solid var(--gray-lighter);
  }
  .nav.active {
    display: flex;
  }
  .nav-toggle {
    display: flex;
  }
  .hero-content h1 {
    font-size: 2rem;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .screenshot-grid {
    grid-template-columns: 1fr;
  }
  .howto-grid {
    grid-template-columns: 1fr;
  }
  .download-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 15px;
    text-align: center;
  }
  .section {
    padding: 60px 0;
  }
  .section-header h2 {
    font-size: 2rem;
  }
}

/* Smooth scroll */
html {
  scroll-behavior: smooth;
}

/* Back to top */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: var(--shadow-lg);
  transition: var(--transition);
  opacity: 0;
  visibility: hidden;
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-3px);
  background: var(--primary-dark);
}