/* --- CSS Variables & Reset --- */
:root {
    --bg-color: #0a0a0a;       /* Deep, rich black instead of pure #000 */
    --text-color-primary: #ffffff;
    --text-color-secondary: #a3a3a3; /* Sophisticated grey */
    --accent-glow: rgba(255, 255, 255, 0.05); /* Subtle light source */
    --font-stack: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --transition-smooth: cubic-bezier(0.4, 0.0, 0.2, 1); /* Apple-like physics */
}

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

html, body {
    height: 100%;
    width: 100%;
    background-color: var(--bg-color);
    color: var(--text-color-primary);
    font-family: var(--font-stack);
    overflow: hidden; /* No scrolling on this single page */
    -webkit-font-smoothing: antialiased; /* Crucial for crisp text on Mac */
    -moz-osx-font-smoothing: grayscale;
}

/* --- Ambient Background --- */
.ambient-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 120vw;
    height: 120vh;
    transform: translate(-50%, -50%);
    background: radial-gradient(circle, var(--accent-glow) 0%, rgba(0,0,0,0) 60%);
    pointer-events: none; /* Let clicks pass through */
    z-index: 0;
    opacity: 0.8;
}

/* --- Navbar --- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    align-items: center;
    padding: 1.5rem 3rem;
    z-index: 100;
    background: linear-gradient(to bottom, rgba(10, 10, 10, 0.9), transparent);
    backdrop-filter: blur(10px);
}

.nav-brand {
    display: flex;
    align-items: center;
}

.brand-logo {
    width: 32px;
    height: 32px;
    color: var(--text-color-primary);
    filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.15));
    transition: filter 0.3s var(--transition-smooth);
}

.brand-logo:hover {
    filter: drop-shadow(0 0 12px rgba(255, 255, 255, 0.3));
}

.nav-spacer {
    flex: 1;
}

.nav-login {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-color-secondary);
    text-decoration: none;
    font-size: 0.8rem;
    font-weight: 400;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    padding: 0.6rem 1.2rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.02);
    backdrop-filter: blur(10px);
    transition: all 0.4s var(--transition-smooth);
}

.nav-login:hover {
    color: var(--text-color-primary);
    border-color: rgba(255, 255, 255, 0.25);
    background: rgba(255, 255, 255, 0.05);
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.05);
}

.login-arrow {
    opacity: 0.6;
    transition: all 0.3s var(--transition-smooth);
}

.nav-login:hover .login-arrow {
    opacity: 1;
    transform: translateX(3px);
}

/* --- Main Layout --- */
body {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    position: relative;
    z-index: 1;
}

.hero-container {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
}

.content-wrapper {
    /* Subtle entrance animation */
    animation: fadeUp 1.2s var(--transition-smooth) forwards;
    opacity: 0;
    transform: translateY(20px);
}

/* --- Typography & Branding --- */
.brand-title {
    /* Fluid typography: scales smoothly between minimum and maximum sizes */
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin-bottom: 1.5rem;
    /* Subtle gradient text for a metallic feel */
    background: linear-gradient(to bottom right, #ffffff, #e0e0e0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 4px 20px rgba(0,0,0,0.5);
}

/* Optical adjustment for wide letter-spacing */
.letter-spacing-tweak {
    letter-spacing: 0.15em;
}

.brand-tagline {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--text-color-secondary);
    font-weight: 300;
    letter-spacing: 0.05em;
    max-width: 600px;
    margin: 0 auto;
    /* Delayed entrance */
    animation: fadeUp 1.2s var(--transition-smooth) 0.3s forwards;
    opacity: 0;
    transform: translateY(20px);
}

/* --- Footer & Login Link --- */
.footer-nav {
    position: absolute;
    bottom: 3rem;
    /* Delayed entrance */
    animation: fadeIn 1.5s var(--transition-smooth) 0.8s forwards;
    opacity: 0;
}

.login-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-color-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 400;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    padding: 0.75rem 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    transition: all 0.4s var(--transition-smooth);
    background: rgba(255, 255, 255, 0.01);
    backdrop-filter: blur(10px); /* Frosted glass effect */
}

.link-arrow {
    transition: transform 0.4s var(--transition-smooth);
    opacity: 0.7;
}

/* --- Hover Effects (The "Platinum" Touch) --- */
.login-link:hover {
    color: var(--text-color-primary);
    border-color: rgba(255, 255, 255, 0.3);
    background: rgba(255, 255, 255, 0.05);
    box-shadow: 0 0 30px rgba(255, 255, 255, 0.05);
}

.login-link:hover .link-arrow {
    transform: translateX(4px);
    opacity: 1;
}

/* --- Animations --- */
@keyframes fadeUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

/* --- Responsive Adjustments --- */
@media (max-width: 768px) {
    .brand-title {
        letter-spacing: 0.15em;
    }
    .footer-nav {
        bottom: 2rem;
    }
}