/* ============================================================
   AI Content Assistant — Component Styles
   ============================================================ */

/* ----- Navigation ----- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border-light);
  z-index: var(--z-nav);
  transition: background var(--transition-base);
}

@media (prefers-color-scheme: dark) {
  .nav {
    background: rgba(15, 23, 42, 0.95);
  }
}

.nav-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-8);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-h4);
  font-weight: var(--weight-bold);
  color: var(--color-primary);
  text-decoration: none;
}

.nav-logo:hover {
  color: var(--color-primary);
}

.nav-logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 16px;
  font-weight: var(--weight-bold);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.nav-link {
  font-size: 14px;
  font-weight: var(--weight-medium);
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-1) 0;
  border-bottom: 2px solid transparent;
  transition: all var(--transition-fast);
  letter-spacing: 0.01em;
}

.nav-link:hover {
  color: var(--color-primary);
}

.nav-link.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.nav-cta {
  padding: var(--space-2) var(--space-5);
  background: var(--color-primary);
  color: white;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: var(--weight-medium);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.nav-cta:hover {
  background: var(--color-primary-light);
  color: white;
}

/* Hamburger */
.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text-primary);
  position: relative;
  transition: all var(--transition-base);
}

.nav-toggle span::before,
.nav-toggle span::after {
  content: '';
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--color-text-primary);
  transition: all var(--transition-base);
}

.nav-toggle span::before { top: -7px; }
.nav-toggle span::after { top: 7px; }

.nav-toggle.active span {
  background: transparent;
}

.nav-toggle.active span::before {
  top: 0;
  transform: rotate(45deg);
}

.nav-toggle.active span::after {
  top: 0;
  transform: rotate(-45deg);
}

/* Mobile nav */
@media (max-width: 767px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    flex-direction: column;
    padding: var(--space-4);
    gap: var(--space-1);
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition-slow);
  }
  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }
  .nav-link {
    padding: var(--space-3) var(--space-4);
    width: 100%;
    border-radius: var(--radius-md);
  }
  .nav-link:hover {
    background: var(--color-bg-secondary);
  }
  .nav-link.active {
    border-bottom: none;
    background: rgba(30, 58, 95, 0.08);
  }
  .nav-cta {
    width: 100%;
    text-align: center;
    margin-top: var(--space-2);
  }
}

/* ----- Buttons ----- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  font-size: var(--text-body);
  font-weight: var(--weight-medium);
  line-height: 1;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
  border: 1.5px solid transparent;
  min-height: 44px;
}

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

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

.btn-primary:hover:not(:disabled) {
  background: var(--color-primary-light);
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-primary:active:not(:disabled) {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  transform: scale(0.98);
}

.btn-secondary {
  background: transparent;
  color: var(--color-text-muted);
  border-color: var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: rgba(30, 58, 95, 0.04);
}

.btn-secondary:active:not(:disabled) {
  background: rgba(30, 58, 95, 0.08);
  transform: scale(0.98);
}

.btn-accent {
  background: var(--color-accent);
  color: white;
  border-color: var(--color-accent);
}

.btn-accent:hover:not(:disabled) {
  background: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-accent:active:not(:disabled) {
  background: var(--color-accent-dark);
  transform: scale(0.98);
}

.btn-ghost {
  background: transparent;
  color: var(--color-primary);
  border-color: transparent;
}

.btn-ghost:hover:not(:disabled) {
  background: rgba(30, 58, 95, 0.06);
}

.btn-ghost:active:not(:disabled) {
  background: rgba(30, 58, 95, 0.12);
}

.btn-danger {
  background: transparent;
  color: var(--color-error);
  border-color: var(--color-error);
}

.btn-danger:hover:not(:disabled) {
  background: #FEF2F2;
}

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-small);
  min-height: 36px;
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-body-large);
  min-height: 52px;
}

.btn-full {
  width: 100%;
}

.btn .spinner {
  width: 16px;
  height: 16px;
  border-width: 2px;
  border-top-color: currentColor;
  border-color: rgba(255,255,255,0.3);
}

/* ----- Form Elements ----- */
.form-group {
  margin-bottom: var(--space-5);
}

.form-label {
  display: block;
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-2);
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  color: var(--color-text-primary);
  font-size: var(--text-body);
  transition: all var(--transition-fast);
  outline: none;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(30, 58, 95, 0.15);
}

.form-input.error,
.form-textarea.error {
  border-color: var(--color-error);
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.15);
}

.form-input:disabled,
.form-textarea:disabled {
  background: var(--color-bg-tertiary);
  color: var(--color-text-light);
  cursor: not-allowed;
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

.form-hint {
  font-size: var(--text-xs);
  color: var(--color-text-light);
  margin-top: var(--space-1);
}

.form-error {
  font-size: var(--text-xs);
  color: var(--color-error);
  margin-top: var(--space-1);
}

.form-char-count {
  text-align: right;
  font-size: var(--text-xs);
  color: var(--color-text-light);
  margin-top: var(--space-1);
}

.form-char-count.over {
  color: var(--color-error);
}

/* ----- Tone Selector ----- */
.tone-selector {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.tone-btn {
  padding: var(--space-2) var(--space-4);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  color: var(--color-text-muted);
  background: var(--color-bg);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.tone-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.tone-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

/* ----- Tip Boxes (persistent guidance) ----- */
.tip-box {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-small);
  line-height: 1.5;
  border-left: 4px solid;
}

.tip-important {
  background: rgba(245, 158, 11, 0.08);
  border-left-color: var(--color-warning);
  color: var(--color-text-primary);
}

.tip-info {
  background: rgba(59, 130, 246, 0.06);
  border-left-color: var(--color-info);
  color: var(--color-text-muted);
}

.tip-success {
  background: rgba(16, 185, 129, 0.08);
  border-left-color: var(--color-accent);
  color: var(--color-text-primary);
}

.tip-box strong {
  color: var(--color-text-primary);
}

.tip-box ul {
  margin: 4px 0 0 16px;
  padding: 0;
}

.tip-box ul li {
  margin-bottom: 2px;
}

/* ----- Cards ----- */
.card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: all var(--transition-base);
}

.card-hover:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

/* ----- Tab System ----- */
.tabs {
  display: flex;
  border-bottom: 2px solid var(--color-border);
  gap: 0;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.tab-btn {
  padding: var(--space-3) var(--space-5);
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
  color: var(--color-text-muted);
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.tab-btn:hover {
  color: var(--color-primary);
}

.tab-btn.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.tab-panel {
  display: none;
  padding: var(--space-6) 0;
}

.tab-panel.active {
  display: block;
  animation: fadeIn 0.2s ease-out;
}

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

/* ----- Code Block ----- */
.code-block {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.6;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
  max-height: 300px;
  overflow-y: auto;
}

/* ----- SERP Preview ----- */
.serp-preview {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  max-width: 600px;
}

.serp-url {
  font-size: var(--text-xs);
  color: #006621;
  margin-bottom: 2px;
}

.serp-title {
  font-size: var(--text-h4);
  color: #1a0dab;
  font-weight: var(--weight-regular);
  margin-bottom: 2px;
  line-height: 1.3;
}

.serp-desc {
  font-size: var(--text-small);
  color: #545454;
  line-height: 1.4;
}

/* ----- Score Gauge ----- */
.score-gauge {
  width: 120px;
  height: 120px;
  position: relative;
  margin: 0 auto;
}

.score-gauge canvas {
  width: 100%;
  height: 100%;
}

.score-value {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: var(--text-h2);
  font-weight: var(--weight-bold);
}

.score-value.good { color: var(--color-accent); }
.score-value.ok { color: var(--color-warning); }
.score-value.bad { color: var(--color-error); }

/* ----- Footer ----- */
.footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--space-12) 0 var(--space-8);
}

.footer-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-8);
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-8);
}

.footer-brand p {
  font-size: var(--text-small);
  color: var(--color-text-muted);
  margin-top: var(--space-3);
  max-width: 300px;
}

.footer h4 {
  font-size: var(--text-small);
  font-weight: var(--weight-semibold);
  margin-bottom: var(--space-4);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
}

.footer a {
  display: block;
  font-size: var(--text-small);
  color: var(--color-text-muted);
  padding: var(--space-1) 0;
}

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

.footer-bottom {
  max-width: var(--container-max);
  margin: var(--space-8) auto 0;
  padding: var(--space-6) var(--space-8) 0;
  border-top: 1px solid var(--color-border-light);
  text-align: center;
  font-size: var(--text-xs);
  color: var(--color-text-light);
}

@media (max-width: 767px) {
  .footer-inner {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
}

/* ----- Back Button ----- */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-small);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
  padding: var(--space-2) 0;
}

.back-link:hover {
  color: var(--color-primary);
}

.back-link::before {
  content: '←';
  font-size: 16px;
}

/* ----- Brand List (Sidebar) ----- */
.brand-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.brand-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.brand-item:hover {
  border-color: var(--color-primary);
  background: rgba(30, 58, 95, 0.04);
}

.brand-item.active {
  border-color: var(--color-primary);
  background: rgba(30, 58, 95, 0.08);
}

.brand-item-name {
  font-size: var(--text-small);
  font-weight: var(--weight-medium);
}

.brand-item-delete {
  color: var(--color-text-light);
  font-size: 16px;
  padding: var(--space-1);
  cursor: pointer;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.brand-item:hover .brand-item-delete {
  opacity: 1;
}

.brand-item-delete:hover {
  color: var(--color-error);
}

/* ----- Empty State ----- */
.empty-state {
  text-align: center;
  padding: var(--space-12) var(--space-4);
  color: var(--color-text-muted);
}

.empty-state-icon {
  font-size: 48px;
  margin-bottom: var(--space-4);
  opacity: 0.4;
}

.empty-state h3 {
  font-size: var(--text-h4);
  margin-bottom: var(--space-2);
}

.empty-state p {
  font-size: var(--text-small);
}

/* ----- Result Actions ----- */
.result-actions {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-top: var(--space-4);
}

/* ----- Loading skeleton ----- */
.skeleton {
  background: linear-gradient(90deg, var(--color-bg-tertiary) 25%, var(--color-bg-secondary) 50%, var(--color-bg-tertiary) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-sm);
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ----- Modal / Confirm Dialog ----- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: var(--z-overlay);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
  animation: fadeIn 0.2s ease-out;
}

.modal {
  background: var(--color-bg);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  max-width: 400px;
  width: 100%;
  box-shadow: var(--shadow-xl);
  animation: modalIn 0.2s ease-out;
}

@keyframes modalIn {
  from { transform: scale(0.95); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.modal h3 {
  margin-bottom: var(--space-3);
}

.modal p {
  font-size: var(--text-small);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

.modal-actions {
  display: flex;
  gap: var(--space-3);
  justify-content: flex-end;
}