:root {
  --bg: #061511;
  --card-bg: rgba(11, 28, 23, 0.78);
  --border: rgba(255, 255, 255, 0.08);
  --text: #f0fdf4;
  --text-muted: #86a798;
  --primary: #10b981;
  --primary-hover: #059669;
  --accent-glow: rgba(16, 185, 129, 0.18);
  --error-bg: rgba(239, 68, 68, 0.12);
  --error-border: rgba(239, 68, 68, 0.25);
  --error-text: #f87171;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
  background-color: var(--bg);
  background-image: 
    radial-gradient(at 0% 0%, rgba(16, 185, 129, 0.2) 0px, transparent 45%),
    radial-gradient(at 100% 100%, rgba(20, 184, 166, 0.14) 0px, transparent 45%);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 24px 20px;
}

header {
  width: 100%;
  max-width: 1200px;
  display: flex;
  justify-content: flex-end;
}

.lang-switch {
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--border);
  border-radius: 10px;
  display: inline-flex;
  padding: 3px;
  gap: 2px;
}

.lang-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  min-width: 46px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 600;
  border-radius: 7px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.lang-btn.active {
  background: var(--primary);
  color: #042f24;
  box-shadow: 0 2px 8px rgba(16, 185, 129, 0.35);
}

.main-container {
  width: 100%;
  max-width: 480px;
  margin: auto 0;
  padding: 16px 0;
}

.card {
  background: var(--card-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 42px 38px;
  box-shadow: 0 24px 50px rgba(0, 0, 0, 0.5);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 24px;
}

.brand-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, #10b981, #0d9488);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 4px 14px rgba(16, 185, 129, 0.25);
}

.brand-icon svg {
  width: 26px;
  height: 26px;
  max-width: 26px;
  max-height: 26px;
  fill: #042f24;
}

.brand-name {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: #f0fdf4;
}

h1 {
  font-size: 21px;
  font-weight: 600;
  margin-bottom: 10px;
  line-height: 1.3;
}

.subtitle {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 22px;
  line-height: 1.55;
}

.features-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: rgba(0, 0, 0, 0.22);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px 18px;
  margin-bottom: 24px;
  font-size: 13.5px;
  color: #d1fae5;
}

.feature-item {
  display: flex;
  align-items: center;
  gap: 12px;
}

.feature-dot {
  width: 6px;
  height: 6px;
  background: #34d399;
  border-radius: 50%;
  flex-shrink: 0;
  box-shadow: 0 0 8px #34d399;
}

.form-group {
  margin-bottom: 18px;
}

label {
  display: block;
  font-size: 13.5px;
  font-weight: 500;
  margin-bottom: 7px;
  color: #cbd5e1;
}

input {
  width: 100%;
  padding: 13px 16px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border);
  border-radius: 11px;
  color: var(--text);
  font-size: 15px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.submit-btn {
  width: 100%;
  padding: 14px;
  background: var(--primary);
  color: #042f24;
  border: none;
  border-radius: 11px;
  font-size: 15.5px;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: background-color 0.2s, transform 0.1s;
  margin-top: 12px;
  box-shadow: 0 4px 16px rgba(16, 185, 129, 0.25);
}

.submit-btn:hover {
  background: var(--primary-hover);
}

.submit-btn:active {
  transform: scale(0.99);
}

.submit-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.alert {
  display: none;
  background: var(--error-bg);
  border: 1px solid var(--error-border);
  color: var(--error-text);
  padding: 12px 14px;
  border-radius: 11px;
  font-size: 13.5px;
  margin-bottom: 20px;
  line-height: 1.45;
}

.spinner {
  display: none;
  width: 17px;
  height: 17px;
  border: 2px solid rgba(4, 47, 36, 0.3);
  border-radius: 50%;
  border-top-color: #042f24;
  animation: spin 0.8s linear infinite;
}

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

.notice {
  margin-top: 22px;
  font-size: 12.5px;
  color: var(--text-muted);
  text-align: center;
  line-height: 1.5;
}

footer {
  width: 100%;
  text-align: center;
  font-size: 13px;
  color: #4b6358;
  padding: 18px 0 6px;
}

@media (max-width: 520px) {
  .card {
    padding: 28px 20px;
    border-radius: 20px;
  }
  h1 {
    font-size: 18.5px;
  }
  .brand-name {
    font-size: 21px;
  }
  .main-container {
    padding: 0;
  }
}