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

:root {
    --primary: #1a3a52;
    --secondary: #4dd4ff;
    --accent: #00b8ff;
    --success: #4ade80;
    --danger: #f87171;
    --dark: #0d1b2a;
    --darker: #000814;
    --light: #ffffff;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-600: #475569;
    --gray-700: #334155;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #1a3a52 0%, #0d1b2a 100%);
    background-attachment: fixed;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--dark);
    position: relative;
}

/* Animated background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(circle at 20% 50%, rgba(77, 212, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(0, 184, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(26, 58, 82, 0.2) 0%, transparent 50%);
    animation: backgroundMove 20s ease infinite;
    z-index: -1;
}

@keyframes backgroundMove {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

/* Logo */
.site-logo {
    position: fixed;
    top: 20px;
    left: 24px;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-img {
    height: 50px;
    width: auto;
    filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.3));
    border-radius: 50%;
}

.logo-text {
    font-size: 24px;
    font-weight: 800;
    color: var(--light);
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    letter-spacing: 1px;
}

/* Auth Container */
.auth-container {
    width: 100%;
    max-width: 480px;
    padding: 24px;
}

.auth-card {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    border-radius: 24px;
    box-shadow: var(--shadow-xl);
    padding: 40px;
    border: 1px solid rgba(77, 212, 255, 0.2);
}

.auth-header {
    text-align: center;
    margin-bottom: 32px;
}

.auth-header h1 {
    font-size: 32px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.auth-header p {
    color: var(--gray-600);
    font-size: 16px;
}

/* Auth Tabs */
.auth-tabs {
    display: flex;
    gap: 8px;
    background: var(--gray-100);
    border-radius: 12px;
    padding: 4px;
    margin-bottom: 32px;
}

.auth-tab {
    flex: 1;
    padding: 12px 24px;
    border: none;
    background: transparent;
    color: var(--gray-600);
    font-size: 15px;
    font-weight: 600;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.auth-tab.active {
    background: var(--light);
    color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.auth-tab:hover:not(.active) {
    color: var(--primary);
}

/* Forms */
.auth-form {
    display: none;
}

.auth-form.active {
    display: block;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 8px;
    font-size: 14px;
}

.form-group input {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid var(--gray-200);
    border-radius: 12px;
    font-size: 15px;
    transition: all 0.3s ease;
    background: var(--light);
}

.form-group input:focus {
    outline: none;
    border-color: var(--secondary);
    box-shadow: 0 0 0 3px rgba(77, 212, 255, 0.1);
}

.form-group input::placeholder {
    color: var(--gray-300);
}

/* Error Message */
.error-message {
    display: none;
    background: linear-gradient(135deg, rgba(248, 113, 113, 0.1) 0%, rgba(239, 68, 68, 0.1) 100%);
    color: var(--danger);
    padding: 12px 16px;
    border-radius: 10px;
    margin-bottom: 20px;
    font-size: 14px;
    border: 1px solid rgba(248, 113, 113, 0.2);
}

/* Submit Button */
.submit-btn {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: var(--light);
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    box-shadow: 0 4px 12px rgba(26, 58, 82, 0.3);
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(26, 58, 82, 0.4);
}

.submit-btn:active {
    transform: translateY(0);
}

.btn-icon {
    transition: transform 0.3s ease;
}

.submit-btn:hover .btn-icon {
    transform: translateX(4px);
}

/* Auth Footer */
.auth-footer {
    margin-top: 24px;
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid var(--gray-200);
}

.auth-footer p {
    color: var(--gray-600);
    font-size: 14px;
}

.auth-footer a {
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
    transition: color 0.3s ease;
}

.auth-footer a:hover {
    color: var(--secondary);
}

/* Responsive */
@media (max-width: 640px) {
    .auth-card {
        padding: 28px 24px;
    }

    .auth-header h1 {
        font-size: 28px;
    }

    .site-logo {
        left: 16px;
        top: 16px;
    }

    .logo-img {
        height: 40px;
    }

    .logo-text {
        font-size: 20px;
    }
}