:root {
  --primary: #4361ee;
  --primary-light: #4895ef;
  --primary-dark: #3a56d4;
  --secondary: #7209b7;
  --success: #06d6a0;
  --warning: #ffd166;
  --danger: #ef476f;
  --light: #f8f9fa;
  --dark: #212529;
  --gray: #6c757d;
  --light-gray: #e9ecef;
  --lighter-gray: #f8f9fa;
  --card-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  --card-shadow-hover: 0 15px 35px rgba(0, 0, 0, 0.15);
  --transition: all 0.3s ease;
  --border-radius: 16px;
  --border-radius-sm: 10px;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  margin: 0;
  padding: 20px;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  color: var(--dark);
  line-height: 1.6;
}

#app {
  width: 100%;
  max-width: 700px;
}

.card {
  width: 100%;
  background: #fff;
  border-radius: var(--border-radius);
  box-shadow: var(--card-shadow);
  padding: 30px;
  text-align: center;
  overflow: visible;
  position: relative;
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--card-shadow-hover);
}

.card-header {
  margin-bottom: 25px;
  position: relative;
}

.card-header::after {
  content: '';
  position: absolute;
  bottom: -12px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(to right, var(--primary-light), var(--primary));
  border-radius: 2px;
}

h2 {
  font-size: 26px;
  margin-bottom: 8px;
  color: var(--primary);
  font-weight: 700;
  letter-spacing: -0.5px;
  line-height: 1.2;
}

.subtitle {
  color: var(--gray);
  font-size: 15px;
  max-width: 90%;
  margin: 0 auto;
  line-height: 1.4;
}

.step-indicator {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  margin: 25px auto 40px;
  max-width: 420px;
  width: 90%;
  padding: 0 10px;
  box-sizing: border-box;
  overflow: visible;
}

.step {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--lighter-gray);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  position: relative;
  transition: var(--transition);
  z-index: 2;
  border: 2px solid var(--light-gray);
  font-size: 16px;
  color: var(--gray);
  flex-shrink: 0;
}

.step.active {
  background: var(--primary);
  color: white;
  transform: scale(1.1);
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(67, 97, 238, 0.2);
}

.step.completed {
  background: var(--success);
  color: white;
  border-color: var(--success);
}

.step-connector {
  position: absolute;
  top: 50%;
  left: 42px;
  right: 42px;
  height: 3px;
  background: var(--light-gray);
  z-index: 1;
  transform: translateY(-50%);
  border-radius: 1.5px;
}

.step-connector-fill {
  height: 100%;
  background: linear-gradient(to right, var(--success), var(--primary));
  transition: width 0.5s ease;
  width: 0%;
  border-radius: 1.5px;
}

.step-text {
  position: absolute;
  top: 50px;
  left: 50%;
  transform: translateX(-50%);
  white-space: nowrap;
  font-size: 12px;
  font-weight: 600;
  color: var(--gray);
  transition: var(--transition);
  text-align: center;
  min-width: 80px;
  line-height: 1.2;
}

.step.active .step-text {
  color: var(--primary);
  font-weight: 700;
  font-size: 13px;
}

.btn {
  margin: 10px;
  padding: 14px 25px;
  border: none;
  border-radius: var(--border-radius-sm);
  background: linear-gradient(to right, var(--primary-light), var(--primary));
  color: #fff;
  cursor: pointer;
  font-size: 16px;
  font-weight: 600;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 10px rgba(67, 97, 238, 0.3);
  min-width: 160px;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: 0.5s;
}

.btn:hover::before {
  left: 100%;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 15px rgba(67, 97, 238, 0.4);
}

.btn:active {
  transform: translateY(0);
  box-shadow: 0 2px 5px rgba(67, 97, 238, 0.3);
}

.btn.back {
  background: linear-gradient(to right, #6c757d, #5a6268);
  box-shadow: 0 4px 10px rgba(108, 117, 125, 0.3);
}

.btn.back:hover {
  box-shadow: 0 8px 15px rgba(108, 117, 125, 0.4);
}

.btn.sms {
  background: linear-gradient(to right, #28a745, #20c997);
  padding: 10px 18px;
  font-size: 14px;
  min-width: auto;
}

.btn.sms:hover {
  box-shadow: 0 5px 12px rgba(40, 167, 69, 0.4);
}

.btn.download {
  background: linear-gradient(to right, var(--secondary), #9d4edd);
  min-width: 220px;
  margin: 15px 5px;
}

/* SIM Selection Buttons - Simple Layout */
.sim-buttons {
  display: flex;
  flex-direction: row;
  justify-content: center;
  margin-bottom: 25px;
  gap: 15px;
  flex-wrap: wrap;
}

.sim-btn-simple {
  background: white;
  border: 2px solid #e9ecef;
  border-radius: 12px;
  padding: 15px 25px;
  margin: 0;
  min-width: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  cursor: pointer;
  font-size: 16px;
  font-weight: 600;
  text-align: center;
}

.viettel-simple {
  border-color: #dc3545;
  color: #dc3545;
}

.viettel-simple:hover {
  background: linear-gradient(135deg, #fff8f8 0%, #ffeaea 100%);
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(220, 53, 69, 0.2);
  border-color: #c82333;
}

.viettel-simple.selected {
  background: linear-gradient(135deg, #dc3545, #e74c3c);
  color: white;
  border-color: #dc3545;
  box-shadow: 0 0 0 3px rgba(220, 53, 69, 0.3);
}

.mobifone-simple {
  border-color: #006064;
  color: #006064;
}

.mobifone-simple:hover {
  background: linear-gradient(135deg, #f8fffe 0%, #e8f5f5 100%);
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(0, 96, 100, 0.2);
  border-color: #004d52;
}

.mobifone-simple.selected {
  background: linear-gradient(135deg, #006064, #00838f);
  color: white;
  border-color: #006064;
  box-shadow: 0 0 0 3px rgba(0, 96, 100, 0.3);
}

.vinaphone-simple {
  border-color: #64b5f6;
  color: #64b5f6;
}

.vinaphone-simple:hover {
  background: linear-gradient(135deg, #f8fcff 0%, #e3f2fd 100%);
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(100, 181, 246, 0.2);
  border-color: #42a5f5;
}

.vinaphone-simple.selected {
  background: linear-gradient(135deg, #64b5f6, #90caf9);
  color: white;
  border-color: #64b5f6;
  box-shadow: 0 0 0 3px rgba(100, 181, 246, 0.3);
}

.sim-btn-simple .checkmark {
  position: absolute;
  top: -8px;
  right: -8px;
  background: #28a745;
  color: white;
  border-radius: 50%;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: bold;
  animation: checkmarkPop 0.3s ease;
  border: 2px solid white;
}

/* OS Selection Buttons */
.os-buttons {
  display: flex;
  flex-direction: row;
  justify-content: center;
  margin-bottom: 25px;
  gap: 20px;
  flex-wrap: wrap;
}

.os-btn-simple {
  background: white;
  border: 2px solid #e9ecef;
  border-radius: 16px;
  padding: 20px;
  margin: 0;
  min-width: 200px;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  position: relative;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(0,0,0,0.08);
  cursor: pointer;
  overflow: hidden;
}

.os-btn-simple::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.5), transparent);
  transition: 0.5s;
}

.os-btn-simple:hover::before {
  left: 100%;
}

.android-simple {
  border-color: #4CAF50;
  background: linear-gradient(135deg, #f8fff8 0%, #ffffff 100%);
}

.android-simple:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(76, 175, 80, 0.2);
  border-color: #4CAF50;
  background: linear-gradient(135deg, #e8f5e8 0%, #f8fff8 100%);
}

.android-simple.selected {
  border-color: #4CAF50;
  background: linear-gradient(135deg, #e8f5e8 0%, #f1f8e9 100%);
  box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.2);
}

.ios-simple {
  border-color: #007AFF;
  background: linear-gradient(135deg, #f8faff 0%, #ffffff 100%);
}

.ios-simple:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0, 122, 255, 0.2);
  border-color: #007AFF;
  background: linear-gradient(135deg, #e8f2ff 0%, #f8faff 100%);
}

.ios-simple.selected {
  border-color: #007AFF;
  background: linear-gradient(135deg, #e8f2ff 0%, #f1f8ff 100%);
  box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.2);
}

.os-btn-simple .os-icon-wrapper {
  width: 50px;
  height: 50px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-right: 15px;
  transition: all 0.3s ease;
}

.android-simple .os-icon-wrapper {
  background: linear-gradient(135deg, #4CAF50, #66BB6A);
  color: white;
}

.ios-simple .os-icon-wrapper {
  background: linear-gradient(135deg, #007AFF, #42a5f5);
  color: white;
}

.os-btn-simple .os-icon-wrapper i {
  font-size: 24px;
  margin: 0;
}

.os-btn-simple .os-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  flex: 1;
}

.os-btn-simple .os-name {
  font-size: 18px;
  font-weight: 700;
  color: #2c3e50;
  margin-bottom: 4px;
}

.os-btn-simple .os-desc {
  font-size: 14px;
  color: #6c757d;
  font-weight: 500;
}

.os-btn-simple .checkmark {
  position: absolute;
  top: 10px;
  right: 10px;
  background: #28a745;
  color: white;
  border-radius: 50%;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: bold;
  animation: checkmarkPop 0.3s ease;
}

/* Android card special styling */
.android-card {
  background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
  border: 2px solid #e3f2fd;
  box-shadow: 0 8px 25px rgba(76, 175, 80, 0.15);
  transition: all 0.4s ease;
  position: relative;
  overflow: hidden;
}

.android-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #4CAF50, #81C784, #A5D6A7);
  animation: shimmer 2s ease-in-out infinite;
}

@keyframes shimmer {
  0%, 100% { opacity: 0.6; }
  50% { opacity: 1; }
}

.android-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 35px rgba(76, 175, 80, 0.25);
  border-color: #4CAF50;
}

.android-header {
  background: linear-gradient(135deg, #4CAF50 0%, #66BB6A 100%);
  color: white;
  padding: 20px;
  margin: -25px -25px 25px -25px;
  border-radius: 12px 12px 0 0;
  box-shadow: 0 4px 15px rgba(76, 175, 80, 0.3);
}

.android-icon {
  font-size: 28px;
  margin-right: 15px;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.android-title {
  font-size: 24px;
  font-weight: 700;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.android-description {
  background: #f1f8e9;
  padding: 20px;
  border-radius: 12px;
  margin: 20px 0;
  border-left: 4px solid #4CAF50;
}

.description-text {
  color: #2e7d32;
  font-size: 16px;
  margin: 0;
  display: flex;
  align-items: center;
  font-weight: 500;
}

.info-icon {
  margin-right: 12px;
  color: #4CAF50;
  font-size: 18px;
}

.download-section {
  margin: 30px 0;
  text-align: center;
}

.android-download {
  background: linear-gradient(135deg, #34A853 0%, #4CAF50 100%);
  padding: 18px 35px;
  border-radius: 50px;
  box-shadow: 0 8px 20px rgba(52, 168, 83, 0.3);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  min-width: 280px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  color: white;
  font-weight: 600;
}

.android-download::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  transition: 0.5s;
}

.android-download:hover::before {
  left: 100%;
}

.android-download:hover {
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 12px 25px rgba(52, 168, 83, 0.4);
  background: linear-gradient(135deg, #2e7d32 0%, #43a047 100%);
}

.android-download i {
  font-size: 24px;
  margin-right: 15px;
}

.download-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.main-text {
  font-size: 16px;
  font-weight: 600;
}

.sub-text {
  font-size: 12px;
  opacity: 0.9;
  font-weight: 400;
  margin-top: 2px;
}

.continue-section {
  margin-top: 30px;
  text-align: center;
}

.continue-btn {
  background: linear-gradient(135deg, #1976d2 0%, #42a5f5 100%);
  padding: 16px 30px;
  border-radius: 25px;
  box-shadow: 0 6px 15px rgba(25, 118, 210, 0.3);
  transition: all 0.3s ease;
  font-weight: 600;
  position: relative;
  overflow: hidden;
}

.continue-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: 0.5s;
}

.continue-btn:hover::before {
  left: 100%;
}

.continue-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 20px rgba(25, 118, 210, 0.4);
  background: linear-gradient(135deg, #1565c0 0%, #1e88e5 100%);
}

.continue-btn i {
  margin-right: 10px;
}

/* App selection buttons with beautiful colors */
.btn.app-4gvpn {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border: none;
  color: white;
  font-weight: 600;
  padding: 16px 24px;
  border-radius: 12px;
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.3);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.btn.app-4gvpn:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(102, 126, 234, 0.4);
  background: linear-gradient(135deg, #5a67d8 0%, #6b46c1 100%);
}

.btn.app-4gvpn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: 0.5s;
}

.btn.app-4gvpn:hover::before {
  left: 100%;
}

.btn.app-npvtunnel {
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  border: none;
  color: white;
  font-weight: 600;
  padding: 16px 24px;
  border-radius: 12px;
  box-shadow: 0 6px 20px rgba(245, 87, 108, 0.3);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.btn.app-npvtunnel:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(245, 87, 108, 0.4);
  background: linear-gradient(135deg, #ec4899 0%, #ef4444 100%);
}

.btn.app-npvtunnel::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: 0.5s;
}

.btn.app-npvtunnel:hover::before {
  left: 100%;
}

/* Step-by-step layout styles */
.step-card {
  background: #f8f9fa;
  border-radius: 12px;
  padding: 20px;
  margin: 15px 0;
  border-left: 4px solid var(--primary);
  position: relative;
  transition: all 0.3s ease;
}

.step-card:hover {
  background: #f1f3f4;
  transform: translateX(5px);
}

.step-number {
  position: absolute;
  left: -15px;
  top: 15px;
  width: 30px;
  height: 30px;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 14px;
  box-shadow: 0 2px 8px rgba(67, 97, 238, 0.3);
}

.step-content {
  margin-left: 25px;
}

.step-content h4 {
  color: var(--primary-dark);
  margin-bottom: 10px;
  font-size: 16px;
  font-weight: 600;
}

.step-content p {
  color: var(--gray);
  margin-bottom: 10px;
  line-height: 1.5;
}

/* Selected app button styles */
.btn.selected {
  position: relative;
  border: 2px solid #28a745;
  box-shadow: 0 0 0 3px rgba(40, 167, 69, 0.2);
}

.checkmark {
  position: absolute;
  top: -5px;
  right: -5px;
  background: #28a745;
  color: white;
  border-radius: 50%;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: bold;
  animation: checkmarkPop 0.3s ease;
}

.btn i {
  margin-right: 10px;
}

.sim-buttons, .app-buttons, .os-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 25px;
  gap: 12px;
}

.option-card {
  background: white;
  border-radius: var(--border-radius-sm);
  padding: 25px;
  margin: 20px 0;
  border: 1px solid var(--light-gray);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
  animation: fadeIn 0.5s ease-in-out;
  text-align: left;
}

.option-header {
  display: flex;
  align-items: center;
  margin-bottom: 15px;
  color: var(--secondary);
}

.option-header i {
  font-size: 20px;
  margin-right: 12px;
  background: linear-gradient(to right, var(--primary-light), var(--primary));
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.option-title {
  font-size: 20px;
  font-weight: 700;
}

.package-list {
  margin: 15px 0;
}

.package-item {
  padding: 12px 0;
  border-bottom: 1px dashed var(--light-gray);
}

.package-item:last-child {
  border-bottom: none;
}

.package-item b {
  color: var(--primary-dark);
}

.syntax-container {
  background: var(--lighter-gray);
  border-radius: var(--border-radius-sm);
  padding: 20px;
  margin: 20px 0;
  border: 1px solid var(--light-gray);
}

/* Image responsive styles */
.image-container {
  text-align: center;
  margin: 15px 0;
  padding: 10px;
  background: #f8f9fa;
  border-radius: 8px;
  border: 1px solid #e9ecef;
}

.package-item img {
  max-width: 400px;
  width: 60%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  transition: transform 0.3s ease;
  display: block;
  margin: 15px auto;
}

.package-item img:hover {
  transform: scale(1.02);
  box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

.download-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 20px;
}

.fade-enter-active, .fade-leave-active {
  transition: opacity 0.4s, transform 0.4s;
}

.fade-enter-from, .fade-leave-to {
  opacity: 0;
  transform: translateY(15px);
}

.progress-container {
  display: none;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(to right, var(--primary-light), var(--primary));
  border-radius: 2px;
  transition: width 0.5s ease;
  max-width: 100%;
  width: 100%;
  position: relative;
  box-sizing: border-box;
}

@keyframes checkmarkPop {
  0% { transform: scale(0); }
  50% { transform: scale(1.2); }
  100% { transform: scale(1); }
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(15px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Large desktop screens - make images even smaller */
@media (min-width: 1200px) {
  .package-item img {
    max-width: 350px;
    width: 50%;
  }
}

/* Medium desktop screens */
@media (min-width: 992px) and (max-width: 1199px) {
  .package-item img {
    max-width: 380px;
    width: 55%;
  }
}

/* Better text wrapping for mobile */
.package-item p {
  word-wrap: break-word;
  line-height: 1.5;
}

/* SMS button responsive */
.package-item > div {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 10px;
}

/* Responsive for simple SIM buttons */
@media (max-width: 768px) {
  .sim-buttons {
    gap: 12px;
  }
  
  .sim-btn-simple {
    min-width: 120px;
    padding: 12px 20px;
    font-size: 15px;
  }
  
  .os-buttons {
    gap: 15px;
  }
  
  .os-btn-simple {
    min-width: 180px;
    padding: 15px;
  }
  
  .os-btn-simple .os-icon-wrapper {
    width: 45px;
    height: 45px;
    margin-right: 12px;
  }
  
  .os-btn-simple .os-icon-wrapper i {
    font-size: 20px;
  }
  
  .os-btn-simple .os-name {
    font-size: 16px;
  }
  
  .os-btn-simple .os-desc {
    font-size: 13px;
  }
  
  .android-header {
    padding: 15px;
    margin: -25px -20px 20px -20px;
  }
  
  .android-icon {
    font-size: 24px;
    margin-right: 12px;
  }
  
  .android-title {
    font-size: 20px;
  }
  
  .android-download {
    min-width: 250px;
    padding: 15px 25px;
  }
  
  .android-download i {
    font-size: 20px;
    margin-right: 12px;
  }
  
  .main-text {
    font-size: 14px;
  }
  
  .sub-text {
    font-size: 11px;
  }
}

@media (max-width: 600px) {
  .sim-buttons {
    flex-direction: column;
    align-items: center;
    gap: 10px;
  }
  
  .sim-btn-simple {
    width: 100%;
    max-width: 200px;
    min-width: auto;
  }
  
  .os-buttons {
    flex-direction: column;
    align-items: center;
    gap: 15px;
  }
  
  .os-btn-simple {
    width: 100%;
    max-width: 280px;
    min-width: auto;
  }
  
  .package-item > div {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  
  .btn.sms {
    width: 100%;
    max-width: 200px;
    margin-top: 10px;
  }
}

/* Mobile Optimization */
@media (max-width: 768px) {
  body {
    padding: 15px;
  }
  
  .card {
    padding: 25px 20px;
    margin: 0;
  }
  
  h2 {
    font-size: 22px;
    line-height: 1.3;
  }
  
  .subtitle {
    font-size: 14px;
    max-width: 100%;
  }
  
  .btn {
    padding: 12px 16px;
    font-size: 14px;
    min-width: 120px;
    margin: 8px 5px;
  }
  
  .btn.download {
    min-width: 200px;
    font-size: 13px;
  }
  
  .step-indicator {
    max-width: 350px;
    width: 85%;
    margin: 20px auto 35px;
    padding: 0 10px;
  }
  
  .step {
    width: 36px;
    height: 36px;
    font-size: 14px;
  }
  
  .step-text {
    font-size: 11px;
    top: 48px;
    max-width: 60px;
    white-space: normal;
    line-height: 1.3;
  }
  
  .step.active .step-text {
    font-size: 12px;
  }
  
  .btn.app-4gvpn, .btn.app-npvtunnel {
    width: 100%;
    max-width: 280px;
    margin: 8px 0;
    padding: 14px 20px;
    font-size: 15px;
  }
  
  .step-card {
    padding: 15px;
    margin: 12px 0;
  }
  
  .step-number {
    width: 25px;
    height: 25px;
    font-size: 12px;
    left: -12px;
  }
  
  .step-content {
    margin-left: 20px;
  }
  
  .step-content h4 {
    font-size: 15px;
  }
  
  .option-card {
    padding: 20px 15px;
    margin: 15px 0;
  }
  
  .package-item {
    padding: 15px 0;
  }
  
  .package-item img {
    max-width: 350px !important;
    width: 80% !important;
    height: auto;
    margin: 10px auto !important;
  }
  
  .syntax-container {
    padding: 15px;
    margin: 15px 0;
  }
  
  .package-list ul {
    padding-left: 15px;
  }
}

@media (max-width: 480px) {
  body {
    padding: 10px;
  }
  
  .card {
    padding: 20px 15px;
  }
  
  .step-indicator {
    margin: 15px auto 30px;
    max-width: 300px;
    width: 80%;
    padding: 0 5px;
  }
  
  h2 {
    font-size: 18px;
    line-height: 1.3;
  }
  
  .subtitle {
    font-size: 13px;
  }
  
  .btn {
    padding: 10px 14px;
    font-size: 13px;
    min-width: 100px;
    margin: 6px 3px;
  }
  
  .btn.download {
    min-width: 180px;
    padding: 12px 16px;
  }
  
  .btn.app-4gvpn, .btn.app-npvtunnel {
    width: 100%;
    max-width: 300px;
    margin: 6px 0;
    padding: 12px 18px;
    font-size: 14px;
  }
  
  .step-card {
    padding: 12px;
    margin: 10px 0;
  }
  
  .step-card:hover {
    transform: none;
  }
  
  .step-number {
    width: 22px;
    height: 22px;
    font-size: 11px;
    left: -11px;
  }
  
  .step-content {
    margin-left: 18px;
  }
  
  .step-content h4 {
    font-size: 14px;
  }
  
  .step {
    width: 32px;
    height: 32px;
    font-size: 13px;
  }
  
  .step-text {
    font-size: 10px;
    top: 42px;
    max-width: 55px;
    white-space: normal;
    line-height: 1.3;
  }
  
  .step.active .step-text {
    font-size: 11px;
  }
  
  .option-card {
    padding: 15px 10px;
  }
  
  .package-item {
    padding: 12px 0;
  }
  
  .package-item img {
    max-width: 300px !important;
    width: 90% !important;
    border-radius: 6px !important;
    margin: 8px auto !important;
  }
  
  .syntax-container {
    padding: 12px;
  }
  
  .option-header {
    flex-direction: column;
    text-align: center;
    gap: 5px;
  }
  
  .option-header i {
    margin-right: 0;
    margin-bottom: 5px;
  }
  
  .option-title {
    font-size: 16px;
  }
  
  /* Fix sim buttons on mobile */
  .sim-btn-simple {
    max-width: 160px;
    padding: 12px 15px;
    font-size: 14px;
    min-width: auto;
  }
  
  /* Fix OS buttons on mobile */
  .os-btn-simple {
    max-width: 260px;
    padding: 12px;
  }
  
  .os-btn-simple .os-name {
    font-size: 15px;
  }
  
  .os-btn-simple .os-desc {
    font-size: 12px;
  }
  
  .android-download {
    min-width: 220px;
    padding: 12px 20px;
    flex-direction: column;
    gap: 8px;
  }
  
  .android-download i {
    margin-right: 0;
    font-size: 22px;
  }
  
  .download-text {
    align-items: center;
    text-align: center;
  }
  
  .continue-btn {
    padding: 14px 25px;
    font-size: 14px;
  }
}