/* ═══════════════════════════════════════════════════════════════
   ProAudioTrainer v2 — Vintage Rack Unit Design System
   Inspired by SSL, Neve, UREI hardware
   ═══════════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Barlow+Condensed:wght@400;600;700;800&family=Share+Tech+Mono&display=swap');

:root {
  /* Chassis Colors */
  --chassis-dark: #1c1c1c;
  --chassis-mid: #2a2a2a;
  --chassis-light: #333333;
  --chassis-accent: #3a3a3a;

  /* Metallic Accents */
  --gold-bright: #d4af37;
  --gold-warm: #c9a84c;
  --gold-dim: #8b7620;
  --brass: #b8960c;

  /* LED States */
  --led-green: #4caf50;
  --led-green-bright: #76c442;
  --led-green-glow: rgba(76, 175, 80, 0.6);
  --led-amber: #f5a623;
  --led-amber-glow: rgba(245, 166, 35, 0.5);
  --led-red: #ff5252;
  --led-red-glow: rgba(255, 82, 82, 0.5);
  --led-warm: #fffacd;
  --led-warm-glow: rgba(255, 250, 205, 0.4);

  /* Text Colors */
  --text-primary: #e8e8e8;
  --text-secondary: #a8a8a8;
  --text-dim: #686868;
  --text-label: #f5f5dc;

  /* Borders & Panels */
  --border-panel: #1a1a1a;
  --border-subtle: #4a4a4a;
  --border-bright: #666666;

  /* Shadows & Depth */
  --shadow-inset: inset 0 2px 4px rgba(0, 0, 0, 0.8), inset 0 -2px 4px rgba(255, 255, 255, 0.05);
  --shadow-button: 0 3px 8px rgba(0, 0, 0, 0.6), 0 1px 2px rgba(255, 255, 255, 0.1);
  --shadow-card: 0 4px 12px rgba(0, 0, 0, 0.8);

  /* Fonts */
  --font-label: 'Barlow Condensed', sans-serif;
  --font-mono: 'Share Tech Mono', monospace;

  /* Dimensions */
  --header-h: 64px;
  --footer-h: 48px;
  --sidebar-w: 200px;
  --radius-panel: 2px;
}

/* ═══════════════════════════════════════════════════════════════
   RESET & BASE
   ═══════════════════════════════════════════════════════════════ */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 14px;
  background: var(--chassis-dark);
}

body {
  background: var(--chassis-dark);
  color: var(--text-primary);
  font-family: var(--font-label);
  font-weight: 400;
  height: 100vh;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ═══════════════════════════════════════════════════════════════
   LOGIN SCREEN
   ═══════════════════════════════════════════════════════════════ */

.login-screen {
  position: fixed;
  inset: 0;
  background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 50%, #1a1a1a 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  overflow: hidden;
}

.login-screen::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    rgba(0, 0, 0, 0.15) 0px,
    rgba(0, 0, 0, 0.15) 1px,
    transparent 1px,
    transparent 2px
  );
  pointer-events: none;
  z-index: 1;
}

.login-chassis {
  background: linear-gradient(180deg, #2a2a2a 0%, #1c1c1c 50%, #1a1a1a 100%);
  border: 2px solid #0a0a0a;
  box-shadow: 
    0 20px 60px rgba(0, 0, 0, 1),
    inset 0 1px 0 rgba(255, 255, 255, 0.1),
    inset 0 -20px 40px rgba(0, 0, 0, 0.8);
  border-radius: 8px;
  padding: 32px 48px;
  max-width: 520px;
  width: 90%;
  z-index: 10;
  position: relative;
}

.login-rack-top,
.login-rack-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.login-rack-bottom {
  margin-bottom: 0;
  margin-top: 24px;
}

.rack-screw {
  width: 8px;
  height: 8px;
  background: radial-gradient(circle at 35% 35%, #f5f5dc, #a8a864);
  border-radius: 50%;
  box-shadow: inset -1px -1px 2px rgba(0, 0, 0, 0.8), 0 1px 2px rgba(0, 0, 0, 0.5);
}

.login-brand {
  text-align: center;
  flex: 1;
  padding: 0 20px;
}

.login-brand-name {
  font-size: 1.4rem;
  font-weight: 800;
  letter-spacing: 3px;
  color: var(--gold-warm);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.8);
  margin-bottom: 2px;
}

.login-brand-sub {
  font-size: 0.65rem;
  letter-spacing: 2px;
  color: var(--text-dim);
  text-transform: uppercase;
}

.login-vu-row {
  display: flex;
  gap: 16px;
  margin-bottom: 24px;
  justify-content: center;
}

.vu-led-strip {
  display: flex;
  gap: 4px;
}

.vu-led {
  width: 6px;
  height: 6px;
  background: #1a1a1a;
  border-radius: 50%;
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.8), 0 0 3px rgba(0, 0, 0, 0.5);
  border: 1px solid #0a0a0a;
  transition: all 0.3s ease;
}

.vu-led.active {
  background: var(--led-green);
  box-shadow: 0 0 6px var(--led-green-glow), inset 0 1px 2px rgba(255, 255, 255, 0.2);
}

.vu-led--yellow {
  color: var(--led-amber);
}

.vu-led--yellow.active {
  background: var(--led-amber);
  box-shadow: 0 0 6px var(--led-amber-glow), inset 0 1px 2px rgba(255, 255, 255, 0.2);
}

.vu-led--red {
  color: var(--led-red);
}

.vu-led--red.active {
  background: var(--led-red);
  box-shadow: 0 0 6px var(--led-red-glow), inset 0 1px 2px rgba(255, 255, 255, 0.2);
}

.login-panel {
  background: linear-gradient(180deg, #222 0%, #1a1a1a 100%);
  border: 1px solid var(--border-panel);
  border-radius: 2px;
  padding: 20px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.form-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--text-label);
  text-transform: uppercase;
}

.form-input-wrap {
  position: relative;
}

.form-input {
  width: 100%;
  padding: 10px 12px;
  background: var(--chassis-dark);
  border: 1px solid var(--border-subtle);
  border-radius: 2px;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.5);
  transition: all 0.2s;
}

.form-input:focus {
  outline: none;
  border-color: var(--gold-warm);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.5), 0 0 8px var(--gold-warm);
}

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

.login-error {
  min-height: 18px;
  font-size: 0.8rem;
  color: var(--led-red);
  text-align: center;
  font-weight: 600;
  animation: errorPulse 0.3s ease;
}

@keyframes errorPulse {
  0% { opacity: 0; transform: scale(0.95); }
  100% { opacity: 1; transform: scale(1); }
}

.btn-rack {
  padding: 10px 20px;
  background: linear-gradient(180deg, #3a3a3a 0%, #2a2a2a 100%);
  border: 1.5px solid var(--gold-warm);
  border-radius: 2px;
  color: var(--gold-warm);
  font-family: var(--font-label);
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 1.5px;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: var(--shadow-button), 0 0 12px rgba(201, 168, 76, 0.15);
  display: flex;
  align-items: center;
  gap: 8px;
  justify-content: center;
}

.btn-rack:hover:not(:disabled) {
  background: linear-gradient(180deg, #4a4a4a 0%, #3a3a3a 100%);
  box-shadow: var(--shadow-button), 0 0 16px rgba(201, 168, 76, 0.25);
  border-color: var(--gold-bright);
  color: var(--gold-bright);
}

.btn-rack:active:not(:disabled) {
  transform: translateY(1px);
  box-shadow: var(--shadow-button), 0 0 8px rgba(201, 168, 76, 0.15);
}

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

.btn-rack--primary {
  width: 100%;
  padding: 12px 20px;
  font-size: 0.9rem;
}

.btn-rack--sm {
  padding: 6px 12px;
  font-size: 0.75rem;
  border-width: 1px;
}

.btn-rack-led {
  width: 6px;
  height: 6px;
  background: #1a1a1a;
  border-radius: 50%;
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.8);
  border: 1px solid #0a0a0a;
  transition: all 0.2s;
  display: inline-block;
}

.btn-rack:hover .btn-rack-led {
  background: var(--led-green);
  box-shadow: 0 0 6px var(--led-green-glow), inset 0 1px 2px rgba(255, 255, 255, 0.2);
}

.login-panel-label {
  text-align: center;
  font-size: 0.65rem;
  letter-spacing: 1.5px;
  color: var(--text-dim);
  margin-top: 12px;
  text-transform: uppercase;
}

/* ═══════════════════════════════════════════════════════════════
   APP SHELL
   ═══════════════════════════════════════════════════════════════ */

.app-shell {
  display: flex;
  flex-direction: column;
  height: 100vh;
  background: var(--chassis-dark);
}

/* ═══════════════════════════════════════════════════════════════
   HEADER / RACK FACEPLATE TOP
   ═══════════════════════════════════════════════════════════════ */

.app-header {
  height: var(--header-h);
  background: linear-gradient(180deg, #2a2a2a 0%, #1c1c1c 100%);
  border-bottom: 2px solid var(--border-panel);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 8px;
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.8), inset 0 1px 0 rgba(255, 255, 255, 0.05);
  z-index: 100;
}

.rack-ear {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 0 8px;
}

.rack-ear--left::before,
.rack-ear--right::before {
  content: '';
  position: absolute;
  width: 2px;
  height: 40px;
  background: repeating-linear-gradient(
    90deg,
    transparent 0px,
    transparent 2px,
    #4a4a4a 2px,
    #4a4a4a 4px
  );
}

.rack-screw {
  width: 6px;
  height: 6px;
  background: radial-gradient(circle at 35% 35%, #f5f5dc, #a8a864);
  border-radius: 50%;
  box-shadow: inset -1px -1px 1px rgba(0, 0, 0, 0.8), 0 1px 2px rgba(0, 0, 0, 0.5);
}

.header-center {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 20px;
}

.header-logo {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 180px;
  padding-right: 20px;
  border-right: 2px solid var(--border-subtle);
}

.logo-brand {
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 1.5px;
  color: var(--gold-warm);
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.8);
}

.logo-model {
  font-size: 0.65rem;
  letter-spacing: 1px;
  color: var(--text-dim);
  text-transform: uppercase;
}

.app-nav {
  display: flex;
  gap: 8px;
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: linear-gradient(180deg, #333 0%, #2a2a2a 100%);
  border: 1px solid var(--border-subtle);
  border-radius: 2px;
  color: var(--text-secondary);
  font-family: var(--font-label);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.nav-btn:hover:not(.coming-soon) {
  background: linear-gradient(180deg, #3a3a3a 0%, #2a2a2a 100%);
  border-color: var(--gold-warm);
  color: var(--gold-warm);
}

.nav-btn.active {
  background: linear-gradient(180deg, #3a4a3a 0%, #2a3a2a 100%);
  border-color: var(--led-green);
  color: var(--led-green-bright);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05), 0 0 10px rgba(76, 175, 80, 0.2);
}

.nav-btn.coming-soon {
  opacity: 0.35;
  cursor: not-allowed;
}

.nav-btn-led {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: #1a1a1a;
  box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.8);
  border: 1px solid #0a0a0a;
  transition: all 0.2s;
}

.nav-btn-led--green {
  color: var(--led-green);
}

.nav-btn-led--green.active {
  background: var(--led-green);
  box-shadow: 0 0 6px var(--led-green-glow), inset 0 1px 1px rgba(255, 255, 255, 0.2);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.vu-meter-compact {
  display: flex;
  gap: 8px;
}

.vu-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.vu-bar-wrap {
  width: 4px;
  height: 32px;
  background: var(--chassis-dark);
  border: 1px solid var(--border-subtle);
  border-radius: 1px;
  overflow: hidden;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.8);
}

.vu-bar-fill {
  width: 100%;
  height: 0%;
  background: linear-gradient(180deg, var(--led-green) 0%, var(--led-amber) 70%, var(--led-red) 100%);
  transition: height 0.1s linear;
  box-shadow: 0 0 4px rgba(76, 175, 80, 0.4);
}

.vu-bar-label {
  font-size: 0.6rem;
  color: var(--text-dim);
  font-weight: 700;
}

.header-user {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-left: 12px;
  border-left: 2px solid var(--border-subtle);
}

.header-username {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-family: var(--font-mono);
  min-width: 80px;
  text-align: right;
}

/* ═══════════════════════════════════════════════════════════════
   MAIN LAYOUT
   ═══════════════════════════════════════════════════════════════ */

.app-main {
  display: flex;
  flex: 1;
  overflow: hidden;
  gap: 0;
}

/* ═══════════════════════════════════════════════════════════════
   SIDEBAR
   ═══════════════════════════════════════════════════════════════ */

.app-sidebar {
  width: var(--sidebar-w);
  background: linear-gradient(180deg, #2a2a2a 0%, #1c1c1c 100%);
  border-right: 2px solid var(--border-panel);
  display: flex;
  flex-direction: column;
  padding: 12px 8px;
  gap: 16px;
  overflow-y: auto;
  flex-shrink: 0;
}

.sidebar-section {
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

.sidebar-section:last-child {
  border-bottom: none;
}

.sidebar-label {
  font-size: 0.6rem;
  font-weight: 800;
  letter-spacing: 2px;
  color: var(--text-label);
  text-transform: uppercase;
  padding: 0 8px 6px 8px;
  display: block;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  background: linear-gradient(180deg, #333 0%, #2a2a2a 100%);
  border: 1px solid var(--border-subtle);
  border-radius: 2px;
  color: var(--text-secondary);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
  width: 100%;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.sidebar-item small {
  display: block;
  font-size: 0.65rem;
  color: var(--text-dim);
  margin-left: auto;
}

.sidebar-item:hover:not(.disabled) {
  background: linear-gradient(180deg, #3a3a3a 0%, #2a2a2a 100%);
  border-color: var(--gold-warm);
  color: var(--gold-warm);
}

.sidebar-item.active {
  background: linear-gradient(180deg, #3a4a3a 0%, #2a3a2a 100%);
  border-color: var(--led-green);
  color: var(--led-green-bright);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05), 0 0 8px rgba(76, 175, 80, 0.15);
}

.sidebar-item.disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.sidebar-led {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: #1a1a1a;
  box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.8);
  border: 1px solid #0a0a0a;
  flex-shrink: 0;
  transition: all 0.2s;
}

.sidebar-led--green.active {
  background: var(--led-green);
  box-shadow: 0 0 5px var(--led-green-glow);
}

.sidebar-led--amber.active {
  background: var(--led-amber);
  box-shadow: 0 0 5px var(--led-amber-glow);
}

.sidebar-led--red.active {
  background: var(--led-red);
  box-shadow: 0 0 5px var(--led-red-glow);
}

.level-item.active {
  background: linear-gradient(180deg, #4a3a2a 0%, #3a2a1a 100%);
  border-color: var(--led-amber);
  color: var(--led-amber);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05), 0 0 8px rgba(245, 166, 35, 0.15);
}

.level-item.active .sidebar-led--amber {
  background: var(--led-amber);
  box-shadow: 0 0 5px var(--led-amber-glow);
}

.highscore-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.hs-entry {
  display: grid;
  grid-template-columns: 20px 1fr 35px;
  gap: 4px;
  padding: 4px 6px;
  font-size: 0.7rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
  background: var(--chassis-dark);
  border-radius: 1px;
}

.hs-rank {
  font-weight: 700;
  color: var(--led-amber);
}

.hs-name {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.hs-score {
  text-align: right;
  font-weight: 600;
  color: var(--led-green);
}

/* ═══════════════════════════════════════════════════════════════
   CONTENT AREA
   ═══════════════════════════════════════════════════════════════ */

.app-content {
  flex: 1;
  overflow-y: auto;
  background: var(--chassis-dark);
  padding: 16px;
}

#main-content {
  width: 100%;
}

/* ═══════════════════════════════════════════════════════════════
   FOOTER / RACK FACEPLATE BOTTOM
   ═══════════════════════════════════════════════════════════════ */

.app-footer {
  height: var(--footer-h);
  background: linear-gradient(180deg, #1c1c1c 0%, #2a2a2a 100%);
  border-top: 2px solid var(--border-panel);
  display: flex;
  align-items: center;
  padding: 0 8px;
  gap: 12px;
  flex-shrink: 0;
  box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.8), inset 0 -1px 0 rgba(255, 255, 255, 0.05);
  z-index: 100;
}

.footer-center {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.shortcuts {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.shortcut {
  font-size: 0.65rem;
  color: var(--text-dim);
  display: flex;
  gap: 3px;
  align-items: center;
}

kbd {
  background: var(--chassis-dark);
  border: 1px solid var(--border-subtle);
  border-radius: 1px;
  padding: 1px 4px;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--text-secondary);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.footer-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.panel-label {
  font-size: 0.6rem;
  letter-spacing: 1px;
  color: var(--text-dim);
  text-transform: uppercase;
}

/* ═══════════════════════════════════════════════════════════════
   UTILITY & SCROLLBARS
   ═══════════════════════════════════════════════════════════════ */

::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border-subtle);
  border-radius: 2px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-dim);
}

/* ═══════════════════════════════════════════════════════════════
   TOAST NOTIFICATIONS
   ═══════════════════════════════════════════════════════════════ */

.toast-container {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 2000;
  pointer-events: none;
}

.toast {
  background: linear-gradient(180deg, #333 0%, #2a2a2a 100%);
  border: 1px solid var(--border-subtle);
  border-radius: 2px;
  padding: 12px 16px;
  font-size: 0.8rem;
  color: var(--text-primary);
  box-shadow: var(--shadow-card);
  animation: toastIn 0.25s ease;
  max-width: 280px;
  pointer-events: auto;
  border-left: 3px solid var(--text-dim);
}

.toast.info {
  border-left-color: var(--led-warm);
}

.toast.success {
  border-left-color: var(--led-green);
}

.toast.error {
  border-left-color: var(--led-red);
}

.toast.warn {
  border-left-color: var(--led-amber);
}

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

/* ═══════════════════════════════════════════════════════════════
   RESPONSIVE
   ═══════════════════════════════════════════════════════════════ */

@media (max-width: 1024px) {
  .app-sidebar {
    width: 160px;
  }

  .footer-center,
  .shortcuts {
    gap: 8px;
  }

  .shortcut {
    font-size: 0.6rem;
  }
}

@media (max-width: 768px) {
  .app-sidebar {
    display: none;
  }

  .header-center {
    gap: 12px;
  }

  .app-nav {
    gap: 4px;
  }

  .nav-btn {
    padding: 6px 10px;
    font-size: 0.7rem;
  }

  .header-logo {
    min-width: 120px;
    border-right: none;
    padding-right: 8px;
  }

  .shortcuts {
    display: none;
  }

  .app-content {
    padding: 12px;
  }
}