:root {
    /* Color Palette - Dark Mode Default */
    --surface-base: #0a0a0c;
    --surface-glass: rgba(20, 20, 25, 0.65);
    --surface-glass-border: rgba(255, 255, 255, 0.08);
    
    --text-primary: #f8f8f2;
    --text-secondary: #9aa0a6;
    
    --brand-primary: #8a2be2;
    --brand-secondary: #4169e1;
    --brand-accent: #00ffff;
    
    --blob-1: rgba(138, 43, 226, 0.4);
    --blob-2: rgba(65, 105, 225, 0.4);

    --radius-md: 16px;
    --radius-lg: 32px;
    --radius-full: 9999px;
    
    --transition-snappy: 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
    --transition-smooth: 0.5s cubic-bezier(0.22, 1, 0.36, 1);
}

[data-theme="light"] {
    --surface-base: #f0f2f5;
    --surface-glass: rgba(255, 255, 255, 0.7);
    --surface-glass-border: rgba(0, 0, 0, 0.08);
    
    --text-primary: #1a1a1c;
    --text-secondary: #5f6368;
    
    --blob-1: rgba(138, 43, 226, 0.2);
    --blob-2: rgba(0, 255, 255, 0.2);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--surface-base);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    transition: background-color var(--transition-smooth), color var(--transition-smooth);
}

/* Background Blobs for Visual Interest */
.background-blobs {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    z-index: -1;
    pointer-events: none;
}

.blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.8;
    animation: float 20s infinite ease-in-out alternate;
}

.blob-1 {
    top: -10%;
    right: -10%;
    width: 500px;
    height: 500px;
    background: var(--blob-1);
    animation-delay: 0s;
}

.blob-2 {
    bottom: -10%;
    left: -10%;
    width: 600px;
    height: 600px;
    background: var(--blob-2);
    animation-delay: -5s;
}

@keyframes float {
    0% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(50px, 50px) scale(1.1); }
    100% { transform: translate(-50px, 100px) scale(0.9); }
}

/* Utilities */
.glass {
    background: var(--surface-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--surface-glass-border);
}

.text-center { text-align: center; }

.gradient-text {
    background: linear-gradient(135deg, var(--brand-primary), var(--brand-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 90%;
    max-width: 1200px;
    height: 70px;
    border-radius: var(--radius-full);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 30px;
    z-index: 100;
    transition: all var(--transition-smooth);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.5px;
}

.logo span {
    color: var(--brand-primary);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.95rem;
    transition: color var(--transition-snappy);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background: var(--brand-primary);
    transition: width var(--transition-snappy);
}

.nav-links a:hover::after {
    width: 100%;
}

.btn-theme {
    background: transparent;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8px;
    border-radius: 50%;
    transition: background-color var(--transition-snappy), transform var(--transition-snappy);
}

.btn-theme:hover {
    background: rgba(128, 128, 128, 0.2);
    transform: rotate(15deg);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 20px 20px;
}

.hero-content {
    max-width: 800px;
    padding: 60px 40px;
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    animation: fadeUp 1s ease-out forwards;
}

.badge {
    display: inline-block;
    padding: 8px 16px;
    border-radius: var(--radius-full);
    background: rgba(138, 43, 226, 0.1);
    border: 1px solid rgba(138, 43, 226, 0.3);
    color: var(--brand-primary);
    font-weight: 600;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 24px;
}

[data-theme="light"] .badge {
    color: var(--brand-secondary);
}

.title {
    font-size: clamp(3rem, 6vw, 5rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -1.5px;
    margin-bottom: 24px;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.6;
    max-width: 600px;
    margin-bottom: 40px;
}

/* Buttons */
.cta-group {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    justify-content: center;
}

.btn {
    padding: 14px 28px;
    border-radius: var(--radius-full);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    font-family: inherit;
    transition: all var(--transition-snappy);
    border: none;
    outline: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--brand-primary), var(--brand-secondary));
    color: white;
    box-shadow: 0 8px 20px rgba(138, 43, 226, 0.3);
}

.btn-primary:hover {
    box-shadow: 0 12px 25px rgba(138, 43, 226, 0.5);
    transform: translateY(-2px);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--surface-glass-border);
    backdrop-filter: blur(8px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

[data-theme="light"] .btn-secondary:hover {
    background: rgba(0, 0, 0, 0.05);
    border-color: rgba(0, 0, 0, 0.2);
}

/* Animations & Interactions */
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card-hover {
    transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
}

.card-hover:hover {
    transform: translateY(-5px);
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.2);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    .hero-content {
        padding: 40px 20px;
    }
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    justify-content: center;
    align-items: center;
    padding: 20px;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    opacity: 0;
    transition: opacity var(--transition-snappy);
}

.modal.show {
    display: flex;
    opacity: 1;
}

.modal-content {
    width: 100%;
    max-width: 400px;
    padding: 40px 32px;
    border-radius: var(--radius-lg);
    position: relative;
    transform: scale(0.9);
    transition: transform var(--transition-snappy);
    box-shadow: 0 24px 48px rgba(0, 0, 0, 0.2);
}

.modal.show .modal-content {
    transform: scale(1);
}

.close-btn {
    position: absolute;
    top: 16px;
    right: 20px;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: color var(--transition-snappy);
}

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

/* Forms */
.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
}

.input-group input {
    width: 100%;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--surface-glass-border);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    outline: none;
    transition: all var(--transition-snappy);
}

[data-theme="light"] .input-group input {
    background: rgba(0, 0, 0, 0.02);
}

.input-group input:focus {
    border-color: var(--brand-primary);
    box-shadow: 0 0 0 2px rgba(138, 43, 226, 0.2);
    background: rgba(255, 255, 255, 0.1);
}

[data-theme="light"] .input-group input:focus {
    background: rgba(0, 0, 0, 0.05);
}

.forgot-password {
    text-align: right;
    margin-bottom: 24px;
}

.forgot-password a, .register-link a {
    color: var(--brand-primary);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 600;
    transition: color var(--transition-snappy);
}

.forgot-password a:hover, .register-link a:hover {
    color: var(--brand-secondary);
}

.register-link {
    margin-top: 24px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}