:root {
  --bg-black: #000000;
  --bg-surface: #09090b;
  --bg-elevated: #121215;
  --bg-drawer: rgba(9, 9, 11, 0.98);
  --border-subtle: rgba(255, 255, 255, 0.1);
  --border-red: rgba(239, 68, 68, 0.4);
  --accent-red: #ef4444;
  --text-main: #ffffff;
  --text-muted: #71717a;
  --text-secondary: #a1a1aa;
  --control-radius: 10px;
  --card-radius: 16px;
  --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
  background: var(--bg-black);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  position: relative;
}

/* 🌌 Canvas Bầu Trời Sao 3D */
#starfield-canvas {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
}

/* 🔴 Ánh Sáng Phát Quang Ambient Glow */
.ambient-glow {
  position: fixed;
  width: 650px;
  height: 650px;
  border-radius: 50%;
  pointer-events: none;
  z-index: 1;
  filter: blur(140px);
  opacity: 0.18;
}

.glow-red {
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle, #ef4444 0%, rgba(0,0,0,0) 70%);
}

/* 🌟 Hero Container Căn Giữa Tuyệt Đối */
.hero-container {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 820px;
  padding: 0 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 9999px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  font-size: 13px;
  font-weight: 500;
  color: #e4e4e7;
  margin-bottom: 24px;
}

.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-red);
  box-shadow: 0 0 10px var(--accent-red);
}

.hero-title {
  font-size: clamp(48px, 7.5vw, 84px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.25;
  padding-bottom: 8px;
  margin-bottom: 20px;
  background: linear-gradient(180deg, #ffffff 0%, #a1a1aa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: clamp(15px, 2vw, 18px);
  line-height: 1.6;
  color: var(--text-secondary);
  max-width: 620px;
  margin-bottom: 36px;
}

/* 🔘 Nút Border Beam Chuyên Nghiệp */
.btn-border-beam {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 32px;
  border-radius: 9999px;
  background: var(--bg-surface);
  color: #ffffff;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid var(--border-red);
  transition: var(--transition);
  text-decoration: none;
  box-shadow: 0 0 25px rgba(239, 68, 68, 0.2);
}

.btn-border-beam:hover {
  background: var(--bg-elevated);
  border-color: var(--accent-red);
  box-shadow: 0 0 40px rgba(239, 68, 68, 0.45);
  transform: translateY(-2px);
}

/* 📱 Right Drawer (Liên Hệ) */
.drawer-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(8px);
  z-index: 100;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.35s ease, visibility 0.35s ease;
}

.drawer-overlay.active {
  opacity: 1;
  visibility: visible;
}

.drawer-panel {
  position: fixed;
  top: 0;
  right: -100%;
  width: 100%;
  max-width: 480px;
  height: 100vh;
  background: var(--bg-drawer);
  border-left: 1px solid var(--border-subtle);
  z-index: 101;
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  transition: right 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: -20px 0 60px rgba(0, 0, 0, 0.9);
  overflow-y: auto;
}

.drawer-overlay.active .drawer-panel {
  right: 0;
}

.drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border-subtle);
}

.drawer-title {
  font-size: 20px;
  font-weight: 600;
}

.drawer-subtitle {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 4px;
}

.btn-close {
  width: 36px;
  height: 36px;
  min-width: 36px;
  min-height: 36px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  flex-shrink: 0;
  transition: var(--transition);
  padding: 0;
}

.btn-close:hover {
  background: rgba(255, 255, 255, 0.16);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.3);
  transform: rotate(90deg);
}

.step-label-text {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.step-indicator-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 24px;
}

.step-item {
  flex: 1;
  height: 4px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 2px;
  transition: var(--transition);
}

.step-item.active {
  background: var(--accent-red);
  box-shadow: 0 0 10px rgba(239, 68, 68, 0.6);
}

.contact-form {
  display: flex;
  flex-direction: column;
  flex: 1;
}

.form-step {
  display: none;
  flex-direction: column;
  gap: 18px;
}

.form-step.active {
  display: flex;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
}

.form-input, .form-select {
  width: 100%;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--control-radius);
  padding: 13px 16px;
  color: #fff;
  font-size: 14px;
  outline: none;
  transition: var(--transition);
}

.form-input:focus, .form-select:focus {
  border-color: var(--accent-red);
  box-shadow: 0 0 15px rgba(239, 68, 68, 0.2);
}

.step-btn-group {
  margin-top: 10px;
  display: flex;
  gap: 12px;
}

.btn-secondary {
  padding: 13px 20px;
  border-radius: 9999px;
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
}

/* 🔔 Toast Container */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.toast {
  background: #121215;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-left: 3px solid var(--accent-red);
  color: #ffffff;
  padding: 14px 20px;
  border-radius: 10px;
  font-size: 13px;
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8);
  animation: slideUp 0.3s ease;
  max-width: 380px;
  line-height: 1.4;
}

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

@media (max-width: 640px) {
  .drawer-panel {
    max-width: 100%;
    padding: 24px 18px;
  }
  .toast-container {
    left: 14px;
    right: 14px;
    bottom: 14px;
  }
  .toast {
    max-width: 100%;
  }
}