:root {
    --primary-color: #A60C0F; /* Deep Red from the image */
    --primary-hover: #c41215;
    --dark-bg: #0a0a0a;
    --darker-bg: #050505;
    --text-light: #ffffff;
    --text-muted: #a0a0a0;
    --card-bg: rgba(255, 255, 255, 0.05);
    --border-color: rgba(255, 255, 255, 0.1);
    --success-color: #2e7d32;
    --error-color: #c62828;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--dark-bg);
    color: var(--text-light);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    /* Subtle background pattern/gradient */
    background: radial-gradient(circle at top, #1a1a1a 0%, var(--darker-bg) 100%);
}

/* Header Styles */
.header {
    padding: 2rem;
    display: flex;
    justify-content: center;
    border-bottom: 1px solid var(--border-color);
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(10px);
}

.logo {
    text-align: center;
}

.logo h1 {
    font-weight: 800;
    font-size: 2.5rem;
    letter-spacing: -1px;
}

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

.subtitle {
    font-weight: 300;
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-top: 0.5rem;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem;
}

.validation-section {
    width: 100%;
    max-width: 600px;
}

/* Glassmorphism Card */
.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 3rem;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
    text-align: center;
    transition: transform 0.3s ease;
}

.glass-card:hover {
    transform: translateY(-5px);
}

.glass-card h2 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.instruction {
    color: var(--text-muted);
    font-size: 1rem;
    margin-bottom: 2.5rem;
    line-height: 1.5;
}

/* Form Styles */
.input-group {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    position: relative;
}

input[type="text"] {
    flex: 1;
    padding: 1rem 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-light);
    font-size: 1.1rem;
    outline: none;
    transition: all 0.3s ease;
    font-family: 'Inter', sans-serif;
}

input[type="text"]::placeholder {
    color: rgba(255, 255, 255, 0.3);
}

input[type="text"]:focus {
    border-color: var(--primary-color);
    background: rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 15px rgba(166, 12, 15, 0.3);
}

button {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    justify-content: center;
    align-items: center;
    min-width: 120px;
}

button:hover {
    background: var(--primary-hover);
    box-shadow: 0 4px 15px rgba(166, 12, 15, 0.4);
}

button:active {
    transform: scale(0.98);
}

/* Loader */
.loader {
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.hidden {
    display: none !important;
}

/* Results Section */
.result-container {
    margin-top: 2rem;
    padding: 1.5rem;
    border-radius: 8px;
    text-align: left;
    animation: fadeIn 0.4s ease-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.result-valid {
    background: rgba(46, 125, 50, 0.1);
    border: 1px solid var(--success-color);
}

.result-invalid {
    background: rgba(198, 40, 40, 0.1);
    border: 1px solid var(--error-color);
}

.status-badge {
    display: inline-block;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.status-valid {
    background: var(--success-color);
    color: white;
}

.status-invalid {
    background: var(--error-color);
    color: white;
}

.result-details p {
    margin-bottom: 0.8rem;
    font-size: 1.05rem;
}

.result-details span.label {
    color: var(--text-muted);
    display: inline-block;
    width: 150px;
}

.result-details span.value {
    font-weight: 600;
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.9rem;
    border-top: 1px solid var(--border-color);
}

/* Responsive */
@media (max-width: 600px) {
    .input-group {
        flex-direction: column;
    }
    
    .glass-card {
        padding: 2rem 1.5rem;
    }
    
    .result-details span.label {
        width: auto;
        display: block;
        margin-bottom: 0.2rem;
    }
}