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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: #FFFFFF;
    color: #000000;
    line-height: 1.6;
    min-height: 100vh;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 3rem;
    background: #FFFFFF;
    border-bottom: 1px solid #F0F0F0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    font-size: 1.75rem;
    font-weight: 600;
    color: #4CAF50;
    text-decoration: none;
    letter-spacing: -0.5px;
}

.nav-menu {
    display: flex;
    gap: 2.5rem;
    list-style: none;
}

.nav-menu a {
    color: #333333;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}

.nav-menu a:hover {
    color: #4CAF50;
}

.auth-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s ease;
    cursor: pointer;
    font-size: 0.9rem;
    border: 1px solid;
}

.btn-login {
    background: #FFFFFF;
    color: #333333;
    border-color: #CCCCCC;
}

.btn-login:hover {
    border-color: #4CAF50;
    color: #4CAF50;
}

.btn-signup {
    background: #4CAF50;
    color: #FFFFFF;
    border-color: #4CAF50;
}

.btn-signup:hover {
    background: #6EC071;
    border-color: #6EC071;
}

/* Modal Overlay */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* Modal Content */
.modal {
    background: #FFFFFF;
    border-radius: 12px;
    padding: 2.5rem;
    width: 90%;
    max-width: 420px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
    transform: translateY(30px) scale(0.95);
    transition: all 0.3s ease;
    position: relative;
}

.modal-overlay.active .modal {
    transform: translateY(0) scale(1);
}

.modal-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: #999;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: all 0.2s ease;
}

.modal-close:hover {
    background: #F5F5F5;
    color: #333;
}

.modal-header {
    text-align: center;
    margin-bottom: 2rem;
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: #000000;
    margin-bottom: 0.5rem;
}

.modal-subtitle {
    color: #666666;
    font-size: 0.9rem;
}