/* ============================================================
   noteweb — Deep Tech Design System
   style.css
   ============================================================ */

/* ---------- CSS Custom Properties ---------- */
:root {
  --color-bg:          #020617;   /* slate-950 */
  --color-surface:     #0f172a;   /* slate-900 */
  --color-surface-mid: rgba(15, 23, 42, 0.8);
  --color-border:      #1e293b;   /* slate-800 */
  --color-accent:      #10b981;   /* emerald-500 */
  --color-accent-dim:  #065f46;   /* emerald-800 */
  --color-text:        #e2e8f0;   /* slate-200 */
  --color-text-muted:  #94a3b8;   /* slate-400 */
  --color-text-faint:  #475569;   /* slate-600 */

  --font-display: 'Outfit', sans-serif;
  --font-body:    'Inter', sans-serif;

  --transition-fast:   150ms ease;
  --transition-base:   300ms ease;
  --transition-slow:   600ms cubic-bezier(0.16, 1, 0.3, 1);

  --glow-sm:  0 0 8px  0 rgba(16, 185, 129, 0.25);
  --glow:     0 0 20px 0 rgba(16, 185, 129, 0.35);
  --glow-lg:  0 0 40px 0 rgba(16, 185, 129, 0.4);
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }

html { font-size: 16px; }

body {
  font-family: var(--font-body);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: #f1f5f9; /* slate-100 */
}

/* ---------- Keyframe Animations ---------- */
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}

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

@keyframes glowPulse {
  0%, 100% { box-shadow: 0 0 12px 0 rgba(16, 185, 129, 0.2); }
  50%       { box-shadow: 0 0 28px 4px rgba(16, 185, 129, 0.5); }
}

@keyframes borderGlow {
  0%, 100% { border-color: rgba(16, 185, 129, 0.2); }
  50%       { border-color: rgba(16, 185, 129, 0.6); }
}

@keyframes scanLine {
  0%   { transform: translateY(-100%); opacity: 0.4; }
  80%  { opacity: 0.4; }
  100% { transform: translateY(200vh); opacity: 0; }
}

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

@keyframes countUp {
  from { opacity: 0; transform: scale(0.85); }
  to   { opacity: 1; transform: scale(1); }
}

/* ---------- Animation Utilities ---------- */
.animate-fade-in    { animation: fadeIn  0.6s ease-out both; }
.animate-slide-up   { animation: slideUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) both; }
.animate-slide-left { animation: slideInLeft 0.6s ease-out both; }
.animate-glow-pulse { animation: glowPulse 3s ease-in-out infinite; }
.animate-border-glow{ animation: borderGlow 2.5s ease-in-out infinite; }
.animate-count-up   { animation: countUp 0.5s ease-out both; }

/* Stagger delays */
.delay-100  { animation-delay: 100ms;  }
.delay-200  { animation-delay: 200ms;  }
.delay-300  { animation-delay: 300ms;  }
.delay-400  { animation-delay: 400ms;  }
.delay-500  { animation-delay: 500ms;  }
.delay-600  { animation-delay: 600ms;  }
.delay-700  { animation-delay: 700ms;  }
.delay-800  { animation-delay: 800ms;  }

/* ---------- Card Component ---------- */
.card {
  display: block;
  background: rgba(15, 23, 42, 0.75);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 1.5rem;
  transition:
    box-shadow var(--transition-base),
    border-color var(--transition-base),
    transform var(--transition-base);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  position: relative;
  overflow: hidden;
}

/* Subtle top-edge highlight */
.card::before {
  content: '';
  position: absolute;
  inset: 0 0 auto;
  height: 1px;
  background: linear-gradient(90deg,
    transparent 0%,
    rgba(16, 185, 129, 0.15) 30%,
    rgba(16, 185, 129, 0.3) 50%,
    rgba(16, 185, 129, 0.15) 70%,
    transparent 100%);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.card:hover {
  box-shadow: 0 0 0 1px rgba(16, 185, 129, 0.15),
              0 0 24px 0 rgba(16, 185, 129, 0.18),
              0 8px 32px -8px rgba(0, 0, 0, 0.6);
  border-color: rgba(16, 185, 129, 0.25);
  transform: translateY(-2px);
}

.card:hover::before {
  opacity: 1;
}

/* Card variants */
.card-solid {
  background: var(--color-surface);
}

.card-glow {
  animation: glowPulse 3s ease-in-out infinite;
}

/* ---------- Button Components ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.875rem;
  letter-spacing: 0.02em;
  border-radius: 8px;
  padding: 0.625rem 1.25rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition:
    background-color var(--transition-fast),
    box-shadow var(--transition-base),
    border-color var(--transition-fast),
    color var(--transition-fast),
    transform var(--transition-fast);
  white-space: nowrap;
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

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

/* Primary button */
.btn-primary {
  background: var(--color-accent);
  color: #020617;
  border-color: var(--color-accent);
}

.btn-primary:hover {
  background: #34d399;
  border-color: #34d399;
  box-shadow: 0 0 20px 2px rgba(16, 185, 129, 0.45),
              0 4px 16px rgba(16, 185, 129, 0.25);
}

/* Secondary / outline button */
.btn-secondary {
  background: transparent;
  color: var(--color-accent);
  border-color: rgba(16, 185, 129, 0.4);
}

.btn-secondary:hover {
  background: rgba(16, 185, 129, 0.08);
  border-color: var(--color-accent);
  box-shadow: 0 0 12px 0 rgba(16, 185, 129, 0.2);
}

/* Ghost button */
.btn-ghost {
  background: transparent;
  color: var(--color-text-muted);
  border-color: transparent;
}

.btn-ghost:hover {
  color: var(--color-text);
  background: rgba(255, 255, 255, 0.04);
}

/* Icon button */
.btn-icon {
  padding: 0.625rem;
  border-radius: 8px;
}

/* Button sizes */
.btn-sm { font-size: 0.8125rem; padding: 0.4rem 0.875rem; border-radius: 6px; }
.btn-lg { font-size: 1rem;      padding: 0.875rem 2rem;   border-radius: 10px; }

/* ---------- Navigation Links ---------- */
.nav-link {
  font-family: var(--font-display);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  padding: 0.375rem 0.875rem;
  border-radius: 6px;
  transition: color var(--transition-fast), background-color var(--transition-fast);
  text-decoration: none;
}

.nav-link:hover {
  color: var(--color-text);
  background: rgba(255, 255, 255, 0.04);
}

.nav-link.active {
  color: var(--color-accent);
}

/* ---------- Badge / Tag ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-family: var(--font-display);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.25rem 0.625rem;
  border-radius: 999px;
  border: 1px solid;
}

.badge-green  { color: #34d399; background: rgba(52, 211, 153, 0.08);  border-color: rgba(52, 211, 153, 0.2); }
.badge-blue   { color: #60a5fa; background: rgba(96, 165, 250, 0.08);  border-color: rgba(96, 165, 250, 0.2); }
.badge-amber  { color: #fbbf24; background: rgba(251, 191, 36, 0.08);  border-color: rgba(251, 191, 36, 0.2); }
.badge-red    { color: #f87171; background: rgba(248, 113, 113, 0.08); border-color: rgba(248, 113, 113, 0.2); }
.badge-purple { color: #a78bfa; background: rgba(167, 139, 250, 0.08); border-color: rgba(167, 139, 250, 0.2); }

/* ---------- Stat / Metric Boxes ---------- */
.stat-box {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1.25rem 1.5rem;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(8px);
}

.stat-value {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  line-height: 1;
  color: #f1f5f9;
  letter-spacing: -0.03em;
}

.stat-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-faint);
  font-weight: 500;
}

/* ---------- Progress Bar ---------- */
.progress-track {
  height: 4px;
  border-radius: 999px;
  background: rgba(30, 41, 59, 1);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, #059669, #34d399);
  box-shadow: 0 0 8px rgba(16, 185, 129, 0.5);
  transition: width 1s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ---------- Input / Form ---------- */
.input {
  width: 100%;
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 0.625rem 1rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  color: var(--color-text);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  outline: none;
}

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

.input:focus {
  border-color: rgba(16, 185, 129, 0.5);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

/* ---------- Code / Terminal Block ---------- */
.terminal {
  background: rgba(2, 6, 23, 0.9);
  border: 1px solid rgba(16, 185, 129, 0.15);
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  font-size: 0.8125rem;
  color: #34d399;
  position: relative;
  overflow: hidden;
}

.terminal-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.875rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid rgba(16, 185, 129, 0.08);
}

.terminal-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
}

.terminal-prompt::before {
  content: '$ ';
  color: var(--color-accent);
}

.terminal-cursor::after {
  content: '█';
  animation: terminalBlink 1s step-end infinite;
  color: var(--color-accent);
}

/* ---------- Section / Divider ---------- */
.section-label {
  font-family: var(--font-display);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, rgba(16, 185, 129, 0.3), transparent);
}

/* ---------- Accent Line / Separator ---------- */
.line-accent {
  height: 1px;
  background: linear-gradient(90deg,
    rgba(16, 185, 129, 0.6),
    rgba(16, 185, 129, 0.1) 60%,
    transparent);
}

/* ---------- Scrollbar (Webkit) ---------- */
::-webkit-scrollbar       { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--color-bg); }
::-webkit-scrollbar-thumb {
  background: rgba(16, 185, 129, 0.25);
  border-radius: 999px;
}
::-webkit-scrollbar-thumb:hover { background: rgba(16, 185, 129, 0.45); }

/* ---------- Selection ---------- */
::selection {
  background: rgba(16, 185, 129, 0.25);
  color: #ecfdf5;
}

/* ---------- Focus-visible outline ---------- */
:focus-visible {
  outline: 2px solid rgba(16, 185, 129, 0.6);
  outline-offset: 2px;
}

/* ---------- Prose / Rich-text content ---------- */
.prose-dark h1, .prose-dark h2, .prose-dark h3 { color: #f1f5f9; }
.prose-dark p    { color: var(--color-text); }
.prose-dark a    { color: var(--color-accent); }
.prose-dark code { background: rgba(16, 185, 129, 0.08); color: #6ee7b7; padding: 0.1em 0.35em; border-radius: 4px; font-size: 0.9em; }
.prose-dark pre  { background: rgba(2, 6, 23, 0.9); border: 1px solid var(--color-border); border-radius: 10px; padding: 1rem 1.25rem; overflow-x: auto; }

/* ---------- Line clamp utility ---------- */
.line-clamp-2 {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ---------- Homepage hero neon text ---------- */
.neon-text {
  text-shadow:
    0 0 10px rgba(16, 185, 129, 0.6),
    0 0 30px rgba(16, 185, 129, 0.4),
    0 0 60px rgba(16, 185, 129, 0.2);
}

/* ---------- Course card arrow reveal (group hover) ---------- */
.course-card .card-arrow { opacity: 0; transition: opacity 0.25s ease; }
.course-card:hover .card-arrow { opacity: 1; }