:root {
    --bg-dark: #121214;
    --bg-surface: #1e1e24;
    --bg-elevated: #282830;
    
    --accent-purple: #818cf8;
    --accent-blue: #38bdf8;
    --accent-teal: #2dd4bf;
    --accent-gradient: linear-gradient(135deg, var(--accent-purple), var(--accent-blue));
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    --nav-height: 70px;
    
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: var(--font-body);
    -webkit-font-smoothing: antialiased;
    padding-bottom: var(--nav-height);
    overflow-x: hidden;
}

h1, h2, h3, h4 {
    font-family: var(--font-heading);
    font-weight: 800;
}

a {
    color: var(--accent-blue);
    text-decoration: none;
}

/* Base Layout Container */
#app-root {
    min-height: calc(100vh - var(--nav-height));
    width: 100%;
    max-width: 600px; /* Mobile first, locked width for center viewing */
    margin: 0 auto;
    padding: 20px;
    /* This custom property is for View Transitions API identifying the main content area */
    view-transition-name: page-content;
}

/* Headings and Intros */
.page-title {
    font-size: 2.5rem;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 20px;
    letter-spacing: -0.5px;
}

.card {
    background: var(--bg-surface);
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
    margin-bottom: 20px;
    border: 1px solid rgba(255,255,255,0.05);
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 12px;
    background: var(--accent-gradient);
    color: #fff;
    font-family: var(--font-heading);
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(56, 189, 248, 0.4);
}

/* Nav */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: var(--nav-height);
    background: rgba(30,30,36, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex;
    justify-content: space-around;
    align-items: center;
    border-top: 1px solid rgba(255,255,255,0.05);
    z-index: 1000;
    view-transition-name: bottom-nav;
}

.nav-link {
    font-family: var(--font-heading);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    transition: color 0.2s ease;
}

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

/* View Transitions API Animations */
::view-transition-old(page-content) {
    animation: fade-out 0.2s cubic-bezier(0.4, 0, 1, 1) both;
}

::view-transition-new(page-content) {
    animation: fade-in 0.3s cubic-bezier(0, 0, 0.2, 1) both;
}

@keyframes fade-out {
    from { opacity: 1; transform: scale(1); }
    to { opacity: 0; transform: scale(0.95); }
}

@keyframes fade-in {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}