:root {
    --primary-color: #2c3e50;
    --accent-color: #3498db;
    --success-color: #2ecc71;
    --background-color: #f5f6fa;
    --card-color: #ffffff;
    --text-color: #2c3e50;
    --border-radius: 10px;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #f6f8fa 0%, #e9ecef 100%);
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    margin: 0;
    padding: 20px;
}

.login-container {
    width: 100%;
    max-width: 450px;
    margin: 2rem auto;
    position: relative;
}

.login-container::before {
    content: '';
    position: absolute;
    top: -10px;
    left: -10px;
    right: -10px;
    bottom: -10px;
    background: linear-gradient(135deg, rgba(255,255,255,0.2), rgba(255,255,255,0.1));
    border-radius: calc(var(--border-radius) + 10px);
    z-index: -1;
}

.login-form {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s ease;
}

.login-form:hover {
    transform: translateY(-5px);
}

.form-header {
    margin-bottom: 2rem;
}

.form-header i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

h1 {
    color: var(--primary-color);
    font-size: 1.8rem;
    margin: 0.5rem 0;
}

.form-group {
    margin-bottom: 1.5rem;
    text-align: left;
    position: relative;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
}

.form-group i {
    position: absolute;
    left: 1rem;
    top: 2.7rem;
    color: #666;
    transition: color 0.3s ease;
}

input[type="email"],
input[type="password"],
input[type="text"] {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #edf2f7;
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: all 0.2s;
    background: white;
}

input:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
    outline: none;
}

input:focus + i {
    color: var(--accent-color);
}

.form-group:focus-within label {
    color: var(--accent-color);
}

.btn {
    width: 100%;
    padding: 1rem;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-top: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255,255,255,0.2),
        transparent
    );
    transition: 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(44, 62, 80, 0.2);
}

.alert {
    background: #fff5f5;
    color: #e74c3c;
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-bottom: 1.5rem;
    text-align: left;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border: 1px solid rgba(211, 47, 47, 0.3);
}

.mb-3 {
    background: #f0fff4;
    color: var(--success-color);
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-bottom: 1.5rem;
    text-align: left;
    border: 1px solid rgba(46, 125, 50, 0.3);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.register-link {
    background: var(--accent-color);
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
    border: 2px solid var(--accent-color);
}

.register-link:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(44, 62, 80, 0.2);
}

.main-header {
    background: var(--primary-color);
    height: 30px;
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    z-index: 1000;
}

.nav-container {
    height: 90%;
    max-width: 1200px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    color: white;
    text-decoration: none;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.auth-links {
    display: flex;
    align-items: center;
}

.register-link {
    background: var(--accent-color);
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
}

.register-link:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(44, 62, 80, 0.2);
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

@media (max-width: 768px) {
    .login-container {
        margin: 1rem auto;
    }

    .login-form {
        padding: 1.5rem;
    }

    .auth-links {
        position: static;
        margin-bottom: 1rem;
        text-align: center;
    }

    .register-link {
        width: 100%;
        justify-content: center;
    }

    h1 {
        font-size: 1.5rem;
    }

    input[type="email"],
    input[type="password"] {
        font-size: 16px; /* Prevents zoom on mobile */
    }
}