:root {
  --bg-body: #060914;
  --bg-card: rgba(18, 24, 43, 0.7);
  --bg-input: rgba(255, 255, 255, 0.04);
  --bg-input-focus: rgba(255, 255, 255, 0.08);
  --bg-hover: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.12);
  --border-hover: rgba(255, 255, 255, 0.25);
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --primary-glow: rgba(59, 130, 246, 0.4);
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --radius-lg: 16px;
  --radius-md: 10px;
  --shadow-card: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg-body: #f5f5f7;
    --bg-card: #ffffff;
    --bg-input: rgba(0, 0, 0, 0.04);
    --bg-input-focus: rgba(0, 0, 0, 0.08);
    --bg-hover: rgba(0, 0, 0, 0.06);
    --border: rgba(0, 0, 0, 0.12);
    --border-hover: rgba(0, 0, 0, 0.25);
    --primary: #007aff;
    --primary-hover: #0051d5;
    --primary-glow: rgba(0, 122, 255, 0.3);
    --text-main: #1d1d1f;
    --text-muted: #86868b;
    --shadow-card: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  }
}

body {
  background-color: var(--bg-body);
  color: var(--text-main);
  font-family: var(--font-sans);
  margin: 0;
  padding-top: 80px;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  overflow-y: scroll;
  transition: background-color 0.3s ease, color 0.3s ease;
}

@media (prefers-color-scheme: light) {
  body {
    background-color: #f5f5f7 !important;
    color: #1d1d1f !important;
  }
}

/* Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { 
  background: rgba(255, 255, 255, 0.2); 
  border-radius: 4px; 
}
::-webkit-scrollbar-thumb:hover { 
  background: rgba(255, 255, 255, 0.3); 
}

@media (prefers-color-scheme: light) {
  ::-webkit-scrollbar-thumb { 
    background: rgba(0, 0, 0, 0.2); 
  }
  ::-webkit-scrollbar-thumb:hover { 
    background: rgba(0, 0, 0, 0.3); 
  }
}

/* Layout */
.page {
  max-width: 1000px;
  margin: 0 auto;
  padding: 20px;
  animation: fadeIn 0.4s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.grid-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 32px;
  align-items: start;
}

@media (max-width: 768px) {
  .grid-layout { grid-template-columns: 1fr; gap: 20px; }
}

/* Side Navigation */
.side-nav {
  position: sticky;
  top: 100px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.side-nav button {
  text-align: left;
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 12px 16px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s;
  font-size: 15px;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 12px;
}

@media (prefers-color-scheme: light) {
  .side-nav button {
    color: #86868b;
  }
  
  .side-nav button:hover {
    background: rgba(0, 0, 0, 0.06);
    color: #1d1d1f;
  }
}

.side-nav button:hover {
  background: var(--bg-hover);
  color: var(--text-main);
}

.side-nav button.active {
  background: rgba(59, 130, 246, 0.15);
  color: #60a5fa;
}

@media (prefers-color-scheme: light) {
  .side-nav button.active {
    background: rgba(0, 122, 255, 0.12);
    color: #007aff;
  }
}

/* Cards */
.card-panel {
  background: var(--bg-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-card);
  transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
}

@media (prefers-color-scheme: light) {
  .card-panel {
    background: #ffffff !important;
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    border-color: rgba(0, 0, 0, 0.12) !important;
    color: #1d1d1f !important;
  }
  
  .card-panel h2,
  .card-panel p,
  .card-panel label,
  .card-panel input,
  .card-panel textarea,
  .card-panel select {
    color: #1d1d1f !important;
  }
  
  .card-panel .form-label {
    color: #86868b !important;
  }
}

.card-header { 
  margin-bottom: 24px; 
  padding-bottom: 16px; 
  border-bottom: 1px solid var(--border); 
}
.card-header h2 { 
  margin: 0; 
  font-size: 20px; 
  font-weight: 600; 
  color: var(--text-main);
}
.card-header p { 
  margin: 6px 0 0; 
  color: var(--text-muted); 
  font-size: 14px; 
}

/* Forms */
.form-group { margin-bottom: 20px; }
.form-label { 
  display: block; 
  margin-bottom: 8px; 
  font-size: 14px; 
  font-weight: 500; 
  color: var(--text-muted); 
}
.form-control {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 10px 14px;
  color: var(--text-main);
  font-size: 15px;
  transition: all 0.2s;
  box-sizing: border-box;
  font-family: inherit;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
  background: var(--bg-input-focus);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

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

.form-control::placeholder {
  color: var(--text-muted);
  opacity: 0.6;
}

/* Avatar Upload */
.avatar-section { 
  display: flex; 
  align-items: center; 
  gap: 20px; 
  margin-bottom: 30px; 
}
.avatar-preview {
  width: 80px; 
  height: 80px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--border);
  background: var(--bg-input);
  transition: border-color 0.3s ease;
}
.avatar-actions { 
  display: flex; 
  flex-direction: column; 
  gap: 6px; 
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-input);
  color: var(--text-main);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}
.btn:hover { 
  background: var(--bg-hover); 
  border-color: var(--border-hover); 
  transform: translateY(-1px);
}
.btn:active {
  transform: translateY(0);
}
.btn-primary {
  background: var(--primary);
  border-color: transparent;
  color: white;
}
.btn-primary:hover { 
  background: var(--primary-hover); 
  box-shadow: 0 4px 12px var(--primary-glow); 
}
.btn-danger {
  background: rgba(220, 38, 38, 0.1);
  color: #f87171;
  border-color: rgba(220, 38, 38, 0.2);
}
.btn-danger:hover { 
  background: rgba(220, 38, 38, 0.2); 
}

@media (prefers-color-scheme: light) {
  .btn-danger {
    background: rgba(220, 38, 38, 0.08);
    color: #dc2626;
    border-color: rgba(220, 38, 38, 0.15);
  }
  .btn-danger:hover {
    background: rgba(220, 38, 38, 0.15);
  }
}

.btn-sm { padding: 6px 12px; font-size: 13px; }
.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

/* Input Group (for verify code) */
.input-group { 
  display: flex; 
  gap: 10px; 
}
.input-group .form-control { 
  flex: 1; 
}

/* Danger Zone */
.danger-zone {
  background: rgba(220, 38, 38, 0.05);
  padding: 20px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(220, 38, 38, 0.15);
  transition: all 0.3s ease;
}

@media (prefers-color-scheme: light) {
  .danger-zone {
    background: rgba(220, 38, 38, 0.04);
    border-color: rgba(220, 38, 38, 0.12);
  }
}

.danger-zone h4 {
  margin: 0 0 8px;
  color: #f87171;
  font-size: 16px;
  font-weight: 600;
}

@media (prefers-color-scheme: light) {
  .danger-zone h4 {
    color: #dc2626;
  }
}

.danger-zone p {
  margin: 0 0 16px;
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* Toast */
.toast-container {
  position: fixed; 
  bottom: 24px; 
  right: 24px; 
  z-index: 100;
  display: flex; 
  flex-direction: column; 
  gap: 10px;
}
.toast {
  background: #1e293b;
  border: 1px solid var(--border);
  color: #f8fafc;
  padding: 12px 16px;
  border-radius: 8px;
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.3);
  font-size: 14px;
  animation: slideIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex; 
  align-items: center; 
  gap: 10px;
}

@media (prefers-color-scheme: light) {
  .toast {
    background: #ffffff;
    border-color: rgba(0, 0, 0, 0.1);
    color: #1d1d1f;
    box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
  }
}

@keyframes slideIn { 
  from { transform: translateY(20px); opacity: 0; } 
  to { transform: translateY(0); opacity: 1; } 
}

/* Utility */
.d-none { display: none !important; }
.mt-4 { margin-top: 1.5rem; }
.mb-2 { margin-bottom: 0.5rem; }
.text-danger { color: #f87171; }

@media (prefers-color-scheme: light) {
  .text-danger { color: #dc2626; }
}