:root {
  --bg-primary: #0a0b0e;
  --card-bg: #13151b;
  --card-border: #232733;
  --card-border-focus: #3b82f6;
  --text-primary: #f3f4f6;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --input-bg: #1a1d26;
  --input-border: #2c3242;
  --input-focus-border: #4f46e5;
  --input-focus-ring: rgba(79, 70, 229, 0.25);
  --btn-primary-bg: #ffffff;
  --btn-primary-text: #0a0b0e;
  --btn-primary-hover: #e5e7eb;
  --btn-secondary-bg: #232733;
  --btn-secondary-text: #e5e7eb;
  --btn-secondary-hover: #2c3242;
  --alert-error-bg: rgba(239, 68, 68, 0.12);
  --alert-error-border: rgba(239, 68, 68, 0.3);
  --alert-error-text: #fca5a5;
  --alert-success-bg: rgba(16, 185, 129, 0.12);
  --alert-success-border: rgba(16, 185, 129, 0.3);
  --alert-success-text: #6ee7b7;
  --radius-card: 16px;
  --radius-input: 10px;
  --radius-btn: 10px;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --transition-fast: 160ms cubic-bezier(0.16, 1, 0.3, 1);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
}

input, textarea {
  user-select: text !important;
  -webkit-user-select: text !important;
}

[hidden] {
  display: none !important;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-family);
  font-size: 14px;
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  padding: 20px;
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(59, 130, 246, 0.08) 0%, transparent 60%),
    radial-gradient(circle at 50% 100%, rgba(99, 102, 241, 0.05) 0%, transparent 60%);
}

.auth-wrap {
  width: 100%;
  max-width: 400px;
}

.auth-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-card);
  padding: 36px 32px 32px;
  box-shadow: 0 20px 40px -15px rgba(0, 0, 0, 0.5), 0 0 1px 1px rgba(255, 255, 255, 0.05) inset;
  transition: border-color var(--transition-fast);
}

.brand-header {
  text-align: center;
  margin-bottom: 28px;
}

.brand-title {
  font-size: 21px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.brand-subtitle {
  font-size: 13px;
  color: var(--text-secondary);
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

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

.form-label {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.01em;
}

.input-wrap {
  position: relative;
  display: flex;
  align-items: center;
}

.input-icon {
  position: absolute;
  left: 12px;
  width: 16px;
  height: 16px;
  color: var(--text-muted);
  pointer-events: none;
  transition: color var(--transition-fast);
}

.form-input {
  width: 100%;
  height: 42px;
  padding: 0 12px 0 38px;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: var(--radius-input);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 14px;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
}

.form-input.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.05em;
  padding-left: 14px;
  text-transform: uppercase;
}

#passwordInput {
  padding-right: 44px;
}

.form-input::placeholder {
  color: var(--text-muted);
}

.form-input:hover {
  border-color: #3f475c;
}

.form-input:focus {
  border-color: var(--input-focus-border);
  box-shadow: 0 0 0 3px var(--input-focus-ring);
  background: #1d212b;
}

.form-input:focus ~ .input-icon {
  color: var(--text-primary);
}

.password-toggle {
  position: absolute;
  right: 8px;
  background: transparent;
  border: none;
  color: var(--text-muted);
  width: 28px;
  height: 28px;
  border-radius: 6px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.password-toggle:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.06);
}

.toggle-icon {
  width: 16px;
  height: 16px;
}

.btn {
  height: 42px;
  border-radius: var(--radius-btn);
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: background var(--transition-fast), transform var(--transition-fast), opacity var(--transition-fast);
}

.btn:active {
  transform: scale(0.985);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.btn-primary {
  background: var(--btn-primary-bg);
  color: var(--btn-primary-text);
  font-weight: 600;
}

.btn-primary:hover:not(:disabled) {
  background: var(--btn-primary-hover);
}

.btn-secondary {
  background: var(--btn-secondary-bg);
  color: var(--btn-secondary-text);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--btn-secondary-hover);
}

.btn-submit {
  margin-top: 6px;
  width: 100%;
}

.btn-spinner {
  width: 16px;
  height: 16px;
  border: 2px solid rgba(0, 0, 0, 0.2);
  border-top-color: #0a0b0e;
  border-radius: 50%;
  animation: spin 600ms linear infinite;
}

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

.form-alert {
  background: var(--alert-error-bg);
  border: 1px solid var(--alert-error-border);
  color: var(--alert-error-text);
  padding: 10px 12px;
  border-radius: var(--radius-input);
  font-size: 13px;
  line-height: 1.4;
  animation: fadeIn var(--transition-fast);
}

.form-alert.success {
  background: var(--alert-success-bg);
  border-color: var(--alert-success-border);
  color: var(--alert-success-text);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Active session view */
.active-session {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.session-badge {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  background: var(--input-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-input);
}

.avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: #3b82f6;
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 16px;
  text-transform: uppercase;
}

.session-meta {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.session-name {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 15px;
}

.session-role {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: #60a5fa;
  text-transform: uppercase;
}

/* Sessions management panel */
.sessions-panel {
  background: rgba(26, 29, 38, 0.6);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-input);
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.sessions-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
}

.sessions-label {
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.sessions-count {
  color: var(--text-muted);
}

.session-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  background: var(--card-bg);
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.04);
}

.session-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 8px rgba(16, 185, 129, 0.5);
  flex-shrink: 0;
}

.session-details {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.session-device {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.session-ip {
  font-size: 11px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.btn-revoke {
  height: 32px;
  font-size: 12px;
  font-weight: 500;
  background: transparent;
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.25);
  border-radius: 8px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-revoke:hover:not(:disabled) {
  background: rgba(239, 68, 68, 0.1);
  border-color: rgba(239, 68, 68, 0.4);
}

.btn-revoke:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.session-action-alert {
  font-size: 12px;
  padding: 8px 10px;
  border-radius: 6px;
  background: var(--alert-success-bg);
  border: 1px solid var(--alert-success-border);
  color: var(--alert-success-text);
  animation: fadeIn var(--transition-fast);
}

.session-action-alert.error {
  background: var(--alert-error-bg);
  border-color: var(--alert-error-border);
  color: var(--alert-error-text);
}

.session-hint {
  font-size: 13px;
  color: var(--text-secondary);
  text-align: center;
}

.button-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.button-group .btn {
  width: 100%;
}

/* Modal window standard (Section 5.2) */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 20px;
  animation: fadeIn var(--transition-fast);
}

.modal-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-card);
  width: 100%;
  max-width: 420px;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.7);
  overflow: hidden;
  animation: modalPop var(--transition-fast);
}

@keyframes modalPop {
  from { opacity: 0; transform: scale(0.96); }
  to { opacity: 1; transform: scale(1); }
}

.modal-header {
  padding: 18px 20px;
  border-bottom: 1px solid var(--card-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
}

.modal-close-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  width: 28px;
  height: 28px;
  border-radius: 6px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  transition: all var(--transition-fast);
}

.modal-close-btn:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.08);
}

.modal-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.modal-text {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.modal-footer {
  padding: 14px 20px;
  border-top: 1px solid var(--card-border);
  background: rgba(0, 0, 0, 0.2);
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}

.modal-footer .btn {
  padding: 0 16px;
}