:root {
    --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e1b4b 100%);
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: rgba(255, 255, 255, 0.1);
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --accent: #6366f1;
    --accent-hover: #818cf8;
    --success: #10b981;
    --error: #ef4444;
}

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

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background: var(--bg-gradient);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    position: relative;
    overflow-x: hidden;
}

.background-decor {
    position: absolute;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(99,102,241,0.2) 0%, rgba(0,0,0,0) 70%);
    top: -100px;
    left: -100px;
    z-index: 0;
    border-radius: 50%;
}

.container {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: 24px;
    padding: 3rem;
    max-width: 700px;
    width: 100%;
    z-index: 10;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #818cf8, #c084fc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 1.1rem;
}

.sample-section h2 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.sample-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 1rem;
}

.sample-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 1rem 0;
    border-radius: 12px;
    text-align: center;
    font-weight: 600;
    font-size: 1.2rem;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: transform 0.2s, background 0.2s;
}

.sample-item:hover {
    transform: translateY(-2px);
    background: rgba(255, 255, 255, 0.15);
}

.input-section {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    align-items: flex-end;
}

.input-group {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.input-group label {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.input-group input {
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 1rem;
    border-radius: 12px;
    color: white;
    font-size: 1.1rem;
    font-family: inherit;
    transition: border-color 0.2s;
    outline: none;
}

.input-group input:focus {
    border-color: var(--accent);
}

.btn-validate, .btn-secondary {
    background: var(--accent);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.btn-validate:hover, .btn-secondary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(99, 102, 241, 0.4);
}

.result-message {
    padding: 1.5rem;
    border-radius: 12px;
    font-weight: 600;
    text-align: center;
    font-size: 1.1rem;
    animation: fadeIn 0.4s ease-out;
}

.result-message.success {
    background: rgba(16, 185, 129, 0.15);
    border: 1px solid var(--success);
    color: #34d399;
}

.result-message.error {
    background: rgba(239, 68, 68, 0.15);
    border: 1px solid var(--error);
    color: #fca5a5;
}

.hidden {
    display: none !important;
}

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

@media (max-width: 600px) {
    .input-section {
        flex-direction: column;
        align-items: stretch;
    }
    .btn-validate {
        width: 100%;
        margin-top: 1rem;
    }
    header h1 {
        font-size: 2rem;
    }
}