/* ========================================================
   worksheet-live: Design System & Tokens
   ======================================================== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Zen+Kaku+Gothic+New:wght@400;500;700&display=swap');

:root {
  --bg-main: #0b0f19;
  --bg-card: rgba(18, 24, 38, 0.75);
  --bg-card-hover: rgba(28, 38, 58, 0.85);
  --bg-input: rgba(15, 23, 42, 0.8);
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-accent: rgba(99, 102, 241, 0.35);

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --accent-indigo: #6366f1;
  --accent-indigo-hover: #4f46e5;
  --accent-cyan: #06b6d4;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #f43f5e;

  --glass-blur: blur(16px);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.15);
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  --transition-smooth: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

body {
  font-family: 'Inter', 'Zen Kaku Gothic New', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--bg-main);
  background-image: 
    radial-gradient(at 10% 10%, rgba(99, 102, 241, 0.08) 0px, transparent 50%),
    radial-gradient(at 90% 90%, rgba(6, 182, 212, 0.05) 0px, transparent 50%);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ========================================================
   Common Layout & Components
   ======================================================== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px;
}

header.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  background: rgba(11, 15, 25, 0.8);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--border-subtle);
  position: sticky;
  top: 0;
  z-index: 50;
}

.brand-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  text-decoration: none;
}

.brand-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--accent-indigo), var(--accent-cyan));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.nav-tabs {
  display: flex;
  gap: 8px;
  background: rgba(15, 23, 42, 0.6);
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.tab-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-smooth);
}

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

.tab-btn.active {
  background: var(--accent-indigo);
  color: #fff;
  box-shadow: 0 2px 10px rgba(99, 102, 241, 0.4);
}

/* Cards & Glassmorphism */
.glass-panel {
  background: var(--bg-card);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-card);
  transition: var(--transition-smooth);
}

.glass-panel:hover {
  border-color: var(--border-accent);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  border: none;
  transition: var(--transition-smooth);
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-indigo), var(--accent-indigo-hover));
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
}

.btn-success {
  background: linear-gradient(135deg, var(--accent-emerald), #059669);
  color: #fff;
}

.btn-sm {
  padding: 6px 12px;
  font-size: 0.85rem;
}

/* Inputs & Forms */
.form-group {
  margin-bottom: 18px;
}

.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.form-input, .form-select, .form-textarea {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  color: var(--text-primary);
  font-size: 0.95rem;
  transition: var(--transition-smooth);
  font-family: inherit;
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--accent-indigo);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.25);
}

/* Drag & Drop Upload Zone */
.drop-zone {
  border: 2px dashed rgba(99, 102, 241, 0.4);
  border-radius: var(--radius-md);
  padding: 36px 20px;
  text-align: center;
  background: rgba(99, 102, 241, 0.03);
  cursor: pointer;
  transition: var(--transition-smooth);
}

.drop-zone:hover, .drop-zone.dragover {
  border-color: var(--accent-indigo);
  background: rgba(99, 102, 241, 0.08);
}

.drop-icon {
  font-size: 2.5rem;
  margin-bottom: 8px;
  color: var(--accent-indigo);
}

/* Badges & Tags */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 9px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.badge-indigo { background: rgba(99, 102, 241, 0.15); color: #a5b4fc; border: 1px solid rgba(99, 102, 241, 0.3); }
.badge-emerald { background: rgba(16, 185, 129, 0.15); color: #6ee7b7; border: 1px solid rgba(16, 185, 129, 0.3); }
.badge-amber { background: rgba(245, 158, 11, 0.15); color: #fcd34d; border: 1px solid rgba(245, 158, 11, 0.3); }
.badge-rose { background: rgba(244, 63, 94, 0.15); color: #fda4af; border: 1px solid rgba(244, 63, 94, 0.3); }

/* Progress Bar */
.progress-container {
  width: 100%;
  height: 12px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-indigo), var(--accent-cyan));
  border-radius: var(--radius-full);
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 0 16px rgba(99, 102, 241, 0.5);
}

/* Animations */
@keyframes pulseGlow {
  0%, 100% { opacity: 0.6; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.03); }
}

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

.animate-slide-up {
  animation: slideInUp 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}