/* Design System */
:root {
  --primary: #0ea5e9;
  --secondary: #6366f1;
  --accent: #f43f5e;
  --dark-bg: #0f172a;
  --card-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Outfit', 'Inter', sans-serif;
  scroll-behavior: smooth;
}

body {
  background-color: var(--dark-bg);
  color: var(--text-main);
  overflow-x: hidden;
  line-height: 1.6;
}

body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at 50% 50%, rgba(14, 165, 233, 0.05), transparent 70%);
  z-index: -1;
  pointer-events: none;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--dark-bg);
}
::-webkit-scrollbar-thumb {
  background: var(--secondary);
  border-radius: 10px;
}

/* Layout Utilities */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

header {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.hero-img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  z-index: -1;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: 
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(14, 165, 233, 0.3), transparent),
    radial-gradient(ellipse 60% 40% at 80% 50%, rgba(99, 102, 241, 0.2), transparent),
    radial-gradient(ellipse 50% 30% at 20% 80%, rgba(139, 92, 246, 0.15), transparent),
    linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
  z-index: -2;
}

.hero-bg::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url("data:image/svg+xml,%3Csvg viewBox='0 0 400 400' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
  opacity: 0.03;
  z-index: -1;
}

.hero-bg::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 200px;
  background: linear-gradient(180deg, rgba(15, 23, 42, 0.8) 0%, transparent 100%);
}

.hero-content {
  text-align: center;
  z-index: 10;
}

.badge {
  background: rgba(14, 165, 233, 0.15);
  color: var(--primary);
  padding: 0.5rem 1rem;
  border-radius: 99px;
  font-size: 0.875rem;
  font-weight: 600;
  border: 1px solid rgba(14, 165, 233, 0.3);
  margin-bottom: 1.5rem;
  display: inline-block;
  backdrop-filter: blur(4px);
}

h1 {
  font-size: clamp(2.5rem, 8vw, 4.5rem);
  font-weight: 800;
  margin-bottom: 1rem;
  background: linear-gradient(to right, #fff, var(--primary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.1;
}

.typing-text {
  font-size: 1.5rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

/* Glassmorphism Components */
.glass-card {
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  padding: 2.5rem;
  transition: var(--transition);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.glass-card:hover {
  transform: translateY(-8px);
  background: rgba(30, 41, 59, 0.85);
  border-color: var(--primary);
  box-shadow: 0 20px 40px rgba(14, 165, 233, 0.15);
}

/* Avatar */
.avatar {
  width: 100%;
  max-width: 400px;
  aspect-ratio: 1;
  border-radius: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 8rem;
  font-weight: 800;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.initials-avatar {
  background: linear-gradient(135deg, #0ea5e9 0%, #6366f1 50%, #8b5cf6 100%);
  color: white;
  position: relative;
  overflow: hidden;
}

.initials-avatar::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  animation: shine 3s infinite;
}

@keyframes shine {
  0% { left: -100%; }
  50%, 100% { left: 100%; }
}

/* Section Header */
.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.section-line {
  width: 60px;
  height: 4px;
  background: var(--primary);
  margin: 0 auto;
  border-radius: 2px;
}

/* Buttons */
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  padding: 1rem 2.5rem;
  border-radius: 12px;
  text-decoration: none;
  font-weight: 600;
  display: inline-block;
  transition: var(--transition);
  border: none;
  cursor: pointer;
  box-shadow: 0 10px 20px rgba(14, 165, 233, 0.3);
}

.btn-primary:hover {
  transform: scale(1.05) translateY(-2px);
  box-shadow: 0 15px 30px rgba(14, 165, 233, 0.5);
}

/* Todo App Styles */
.todo-container {
  width: 100%;
  max-width: 400px;
  margin: 0 auto;
}

.todo-header {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.todo-input {
  flex: 1;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  padding: 0.75rem 1rem;
  border-radius: 10px;
  color: white;
  outline: none;
}

.todo-input:focus {
  border-color: var(--primary);
}

.todo-add {
  background: var(--primary);
  border: none;
  width: 42px;
  height: 42px;
  border-radius: 10px;
  color: white;
  cursor: pointer;
}

.todo-list {
  list-style: none;
}

.todo-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: rgba(255, 255, 255, 0.03);
  margin-bottom: 0.5rem;
  border-radius: 10px;
  animation: slideIn 0.3s ease;
}

.todo-item.completed span {
  text-decoration: line-through;
  opacity: 0.5;
}

.todo-actions {
  display: flex;
  gap: 0.5rem;
}

.todo-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  transition: var(--transition);
}

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

.todo-btn.delete:hover {
  color: var(--accent);
}

/* Animations */
@keyframes slideIn {
  from { opacity: 0; transform: translateX(-20px); }
  to { opacity: 1; transform: translateX(0); }
}

/* Responsive Grid */
.grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

/* Navbar */
nav {
  position: fixed;
  top: 0;
  width: 100%;
  padding: 1.5rem 0;
  z-index: 1000;
  transition: var(--transition);
}

nav.scrolled {
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(10px);
  padding: 1rem 0;
  border-bottom: 1px solid var(--glass-border);
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-weight: 800;
  font-size: 1.5rem;
  color: var(--text-main);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
}

.nav-links a:hover {
  color: var(--primary);
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links { display: none; }
  h1 { font-size: 2.5rem; }
  
  /* Featured Card Mobile Stack */
  .grid > .glass-card[style*="grid-column: span 2"] {
    grid-column: span 1 !important;
    flex-direction: column !important;
    height: auto !important;
  }
  
  .grid > .glass-card[style*="grid-column: span 2"] > div {
    width: 100% !important;
    height: auto !important;
  }
}