/* ============================================
   KGS Web App — Design System
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* --- CSS Custom Properties --- */
:root {
  /* Primary palette */
  --primary: #1a1a6e;
  --primary-light: #2d2d9e;
  --primary-dark: #0e0e4a;
  --primary-gradient: linear-gradient(135deg, #1a1a6e 0%, #2d2d9e 50%, #4a3aaf 100%);

  /* Accent */
  --accent: #4f8cff;
  --accent-light: #7aabff;
  --accent-glow: rgba(79, 140, 255, 0.3);

  /* Success / Error / Warning */
  --success: #22c55e;
  --success-bg: rgba(34, 197, 94, 0.1);
  --error: #ef4444;
  --error-bg: rgba(239, 68, 68, 0.1);
  --warning: #f59e0b;

  /* Neutrals */
  --bg: #f0f2f7;
  --surface: #ffffff;
  --surface-hover: #f8f9fc;
  --border: #e2e6ef;
  --border-focus: #4f8cff;
  --text-primary: #1a1a2e;
  --text-secondary: #6b7280;
  --text-muted: #9ca3af;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.1), 0 4px 12px rgba(0,0,0,0.05);
  --shadow-xl: 0 20px 60px rgba(0,0,0,0.12), 0 8px 20px rgba(0,0,0,0.06);
  --shadow-glow: 0 0 30px rgba(79, 140, 255, 0.15);

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- Reset & Base --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text-primary);
  background: var(--bg);
  line-height: 1.6;
  min-height: 100vh;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

img {
  max-width: 100%;
  display: block;
}

/* --- Keyframe Animations --- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

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

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

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* --- Utility Classes --- */
.animate-fade-in-up {
  animation: fadeInUp 0.6s ease-out both;
}

.animate-fade-in {
  animation: fadeIn 0.5s ease-out both;
}

.animate-scale-in {
  animation: scaleIn 0.4s ease-out both;
}

/* Staggered delays */
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }
.delay-5 { animation-delay: 0.5s; }

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  letter-spacing: 0.01em;
}

.btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(rgba(255,255,255,0.15), transparent);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.btn:hover::after {
  opacity: 1;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--primary-gradient);
  color: #fff;
  box-shadow: 0 4px 16px rgba(26, 26, 110, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 6px 24px rgba(26, 26, 110, 0.4);
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(0) scale(0.97);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--border);
}

.btn-outline:hover {
  border-color: var(--primary);
  background: rgba(26, 26, 110, 0.04);
}

.btn-danger {
  background: var(--error);
  color: #fff;
}

.btn-lg {
  padding: 14px 32px;
  font-size: 1rem;
  border-radius: var(--radius-md);
}

.btn-full {
  width: 100%;
}

.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: var(--radius-sm);
}

/* Loading state */
.btn.loading {
  pointer-events: none;
  opacity: 0.8;
}

.btn .spinner {
  width: 20px;
  height: 20px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

/* --- Form Elements --- */
.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.form-label .required {
  color: var(--error);
  margin-left: 2px;
}

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

.input-wrapper .input-icon {
  position: absolute;
  left: 14px;
  color: var(--text-muted);
  font-size: 1.1rem;
  pointer-events: none;
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
}

.input-wrapper .input-icon svg {
  width: 20px;
  height: 20px;
  stroke: var(--text-muted);
  transition: stroke var(--transition-fast);
}

.form-input {
  width: 100%;
  padding: 13px 16px 13px 46px;
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--text-primary);
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-md);
  outline: none;
  transition: all var(--transition-fast);
}

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

.form-input:hover {
  border-color: #c5cad6;
}

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

.form-input:focus ~ .input-icon svg,
.form-input:focus ~ .input-icon {
  color: var(--accent);
}

.form-input:focus + .input-icon svg {
  stroke: var(--accent);
}

.input-wrapper:focus-within .input-icon svg {
  stroke: var(--accent);
}

.input-action {
  position: absolute;
  right: 12px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  padding: 4px;
  display: flex;
  align-items: center;
  transition: color var(--transition-fast);
}

.input-action:hover {
  color: var(--text-primary);
}

.input-action svg {
  width: 20px;
  height: 20px;
}

.form-error {
  font-size: 0.8rem;
  color: var(--error);
  margin-top: 6px;
  display: flex;
  align-items: center;
  gap: 4px;
  animation: fadeIn 0.3s ease;
}

.form-input.error {
  border-color: var(--error);
  box-shadow: 0 0 0 3px var(--error-bg);
}

/* Checkbox */
.checkbox-wrapper {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.checkbox-wrapper input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
  cursor: pointer;
}

.checkbox-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  user-select: none;
}

/* --- Card --- */
.card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border);
  overflow: hidden;
}

.card-body {
  padding: 24px;
}

/* --- Toast / Alert Messages --- */
.toast {
  position: fixed;
  top: 24px;
  right: 24px;
  padding: 14px 20px;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: 9999;
  animation: slideInRight 0.4s ease-out, fadeOut 0.4s ease 3.6s forwards;
  box-shadow: var(--shadow-lg);
  max-width: 400px;
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(40px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadeOut {
  to {
    opacity: 0;
    transform: translateY(-10px);
  }
}

.toast-success {
  background: #f0fdf4;
  color: #166534;
  border: 1px solid #bbf7d0;
}

.toast-error {
  background: #fef2f2;
  color: #991b1b;
  border: 1px solid #fecaca;
}

.toast-info {
  background: #eff6ff;
  color: #1e40af;
  border: 1px solid #bfdbfe;
}

/* --- Responsive helpers --- */
@media (max-width: 480px) {
  .hide-mobile {
    display: none !important;
  }
}

/* ============================================
   Dark Mode
   ============================================ */

/* Smooth theme transition */
body,
body *,
body *::before,
body *::after {
  transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
}

/* Dark mode variables */
[data-theme="dark"] {
  --primary: #7c8cff;
  --primary-light: #9aa6ff;
  --primary-dark: #5b6bdf;
  --primary-gradient: linear-gradient(135deg, #3a3aaf 0%, #5b5bd6 50%, #7c6bef 100%);

  --accent: #6ea8ff;
  --accent-light: #90bcff;
  --accent-glow: rgba(110, 168, 255, 0.2);

  --success: #34d399;
  --success-bg: rgba(52, 211, 153, 0.12);
  --error: #f87171;
  --error-bg: rgba(248, 113, 113, 0.12);
  --warning: #fbbf24;

  --bg: #0f1117;
  --surface: #1a1d27;
  --surface-hover: #22252f;
  --border: #2a2e3a;
  --border-focus: #6ea8ff;
  --text-primary: #e8eaed;
  --text-secondary: #9ca3b0;
  --text-muted: #6b7280;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3), 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.35), 0 2px 4px rgba(0,0,0,0.2);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.4), 0 4px 12px rgba(0,0,0,0.25);
  --shadow-xl: 0 20px 60px rgba(0,0,0,0.45), 0 8px 20px rgba(0,0,0,0.3);
  --shadow-glow: 0 0 30px rgba(110, 168, 255, 0.1);
}

/* Dark mode specific overrides */
[data-theme="dark"] .form-input:hover {
  border-color: #3a3e4a;
}

[data-theme="dark"] .toast-success {
  background: #052e16;
  color: #86efac;
  border-color: #166534;
}

[data-theme="dark"] .toast-error {
  background: #450a0a;
  color: #fca5a5;
  border-color: #991b1b;
}

[data-theme="dark"] .toast-info {
  background: #172554;
  color: #93c5fd;
  border-color: #1e40af;
}

/* --- Theme Toggle Button --- */
.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--border);
  background: var(--surface);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  padding: 0;
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
}

.theme-toggle:hover {
  border-color: var(--accent);
  background: var(--surface-hover);
  transform: scale(1.05);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
  transition: all 0.3s ease;
}

.theme-toggle .icon-sun {
  stroke: #f59e0b;
  display: none;
}

.theme-toggle .icon-moon {
  stroke: var(--text-secondary);
}

[data-theme="dark"] .theme-toggle .icon-sun {
  display: block;
}

[data-theme="dark"] .theme-toggle .icon-moon {
  display: none;
}