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

:root {
    --primary: #667eea;
    --primary-dark: #5568d3;
    --secondary: #764ba2;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border: #334155;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, #1a1f35 100%);
    color: var(--text-primary);
    min-height: 100vh;
    padding: 2rem 1rem;
    line-height: 1.6;
}

.container {
    max-width: 600px;
    margin: 0 auto;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 3rem;
}

.logo {
    display: inline-block;
    margin-bottom: 1rem;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    background: var(--bg-card);
    padding: 0.5rem;
    border-radius: 12px;
    border: 1px solid var(--border);
}

.tab-btn {
    flex: 1;
    padding: 1rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 500;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.tab-btn:hover {
    background: rgba(102, 126, 234, 0.1);
    color: var(--primary);
}

.tab-btn.active {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.tab-btn svg {
    width: 20px;
    height: 20px;
}

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

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

/* Form */
.check-form {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.form-group {
    margin-bottom: 1.5rem;
}

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

input {
    width: 100%;
    padding: 1rem;
    background: var(--bg-secondary);
    border: 2px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s ease;
    font-family: 'Inter', monospace;
}

input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

input::placeholder {
    color: var(--text-secondary);
    font-family: 'Inter', monospace;
}

.hint {
    display: block;
    margin-top: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Button */
.btn-primary {
    width: 100%;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border: none;
    border-radius: 8px;
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.4);
}

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

.btn-primary.loading .btn-text {
    opacity: 0;
}

.btn-primary.loading .btn-loader {
    opacity: 1;
}

.btn-loader {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    opacity: 0;
}

@keyframes spin {
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

/* Results */
.results {
    margin-top: 2rem;
}

.result-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border);
    animation: slideUp 0.4s ease;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.result-card.success {
    border-left: 4px solid var(--success);
}

.result-card.error {
    border-left: 4px solid var(--error);
}

.result-card.warning {
    border-left: 4px solid var(--warning);
}

.result-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.result-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.result-icon.success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
}

.result-icon.error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error);
}

.result-icon.warning {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
}

.result-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.result-details {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.detail-row {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem;
    background: var(--bg-secondary);
    border-radius: 8px;
}

.detail-label {
    color: var(--text-secondary);
    font-weight: 500;
}

.detail-value {
    font-weight: 600;
    color: var(--text-primary);
}

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

/* Footer */
.footer {
    text-align: center;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 0.875rem;
}

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

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

/* Responsive */
@media (max-width: 640px) {
    h1 {
        font-size: 2rem;
    }
    
    .tab-btn {
        font-size: 0.75rem;
        padding: 0.75rem;
    }
    
    .tab-btn svg {
        display: none;
    }
    
    .check-form {
        padding: 1.5rem;
    }
}