:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --bg-light: #f8fafc;
    --bg-dark: #0f172a;
    --card-light: #ffffff;
    --card-dark: #1e293b;
    --text-light: #1e293b;
    --text-dark: #f1f5f9;
    --text-muted: #64748b;
    --border-light: #e2e8f0;
    --border-dark: #334155;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --radius: 12px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
    background-color: var(--bg-light);
    color: var(--text-light);
    transition: background-color 0.3s, color 0.3s;
    overflow-x: hidden;
}

body.dark-mode {
    background-color: var(--bg-dark);
    color: var(--text-dark);
}

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

/* Typography */
h1 { font-size: 2.5rem; font-weight: 800; margin-bottom: 1rem; }
p { line-height: 1.6; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    padding: 0.7rem 1.4rem;
    border-radius: 100px;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: none;
    text-decoration: none;
    gap: 0.6rem;
    letter-spacing: 0.3px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-hover));
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.5);
}

.btn-outline {
    background: rgba(0, 0, 0, 0.02);
    border: 1px solid var(--border-light);
    color: var(--text-light);
}

.dark-mode .btn-outline {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-dark);
    backdrop-filter: blur(10px);
}

.btn-outline:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

/* Custom Loader Animation */
.loader-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
}

.loader {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    position: relative;
    background: var(--primary);
    animation: loaderPulse 1.5s infinite ease-in-out;
}

.loader::after {
    content: '';
    position: absolute;
    inset: -10px;
    border-radius: 50%;
    border: 2px solid var(--primary);
    opacity: 0.5;
    animation: loaderRipple 1.5s infinite ease-out;
}

@keyframes loaderPulse {
    0%, 100% { transform: scale(1); opacity: 0.8; }
    50% { transform: scale(1.1); opacity: 1; box-shadow: 0 0 30px var(--primary); }
}

@keyframes loaderRipple {
    0% { transform: scale(1); opacity: 0.5; }
    100% { transform: scale(2.5); opacity: 0; }
}

/* Cards */
.card {
    background-color: var(--card-light);
    border: 1px solid var(--border-light);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.dark-mode .card {
    background-color: var(--card-dark);
    border-color: var(--border-dark);
}

/* Grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

/* Navigation */
nav {
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-light);
    background-color: var(--card-light);
}

.dark-mode nav {
    background-color: var(--card-dark);
    border-color: var(--border-dark);
}

.logo {
    font-weight: 800;
    font-size: 1.5rem;
    color: var(--primary);
}

/* Modal/Overlays */
.overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    display: none; /* Flex when active */
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(4px);
}

/* Helper Classes */
.hidden { display: none !important; }
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.mt-4 { margin-top: 1rem; }