:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --success-color: #10b981;
    --error-color: #ef4444;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-gradient-start: #f3f4f6;
    --bg-gradient-end: #e5e7eb;
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.5);
    --shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

body {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, #e0c3fc 0%, #8ec5fc 100%);
    overflow: hidden;
    position: relative;
}

/* Background Shapes */
.background-shape {
    position: absolute;
    filter: blur(80px);
    z-index: -1;
    animation: drift 20s infinite alternate;
}

.shape-1 {
    width: 400px;
    height: 400px;
    background: #a78bfa;
    top: -100px;
    left: -100px;
    border-radius: 50%;
    opacity: 0.6;
}

.shape-2 {
    width: 350px;
    height: 350px;
    background: #60a5fa;
    bottom: -50px;
    right: -50px;
    border-radius: 50%;
    opacity: 0.6;
    animation-delay: -10s;
}

@keyframes drift {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(30px, 30px) scale(1.1); }
}

.container {
    width: 100%;
    max-width: 420px;
    padding: 20px;
}

.card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: 20px;
    border: 1px solid var(--glass-border);
    padding: 40px 30px;
    box-shadow: var(--shadow);
    text-align: center;
    transform: translateY(0);
    transition: transform 0.3s ease;
}

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

header h1 {
    color: var(--text-color);
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 5px;
    background: linear-gradient(to right, #4f46e5, #9333ea);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 30px;
}

/* Form Styles */
.input-group {
    position: relative;
    margin-bottom: 25px;
    text-align: left;
}

.input-group label {
    display: block;
    color: var(--text-color);
    font-weight: 600;
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.input-group input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.8);
    color: var(--text-color);
    outline: none;
}

.input-group input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.2);
}

button {
    width: 100%;
    padding: 14px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    box-shadow: 0 4px 6px rgba(79, 70, 229, 0.25);
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(79, 70, 229, 0.3);
}

button:active {
    transform: translateY(0);
}

/* Spinner */
.spinner {
    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;
}

.hidden {
    display: none !important;
}

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

/* Result Section */
.result {
    margin-top: 30px;
    padding: 20px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.5);
    animation: fadeIn 0.5s ease;
}

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

.icon-container {
    margin-bottom: 10px;
}

.icon {
    width: 48px;
    height: 48px;
}

.success-icon {
    color: var(--success-color);
    display: none;
}

.error-icon {
    color: var(--error-color);
    display: none;
}

/* Specific state styles */
.result.valid .success-icon { display: inline-block; }
.result.invalid .error-icon { display: inline-block; }

.result.valid {
    border-left: 5px solid var(--success-color);
    background: rgba(16, 185, 129, 0.1);
}

.result.invalid {
    border-left: 5px solid var(--error-color);
    background: rgba(239, 68, 68, 0.1);
}

#resultTitle {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 5px;
    color: var(--text-color);
}

#resultMessage {
    color: var(--text-light);
    font-size: 0.9rem;
}

footer {
    margin-top: 20px;
    text-align: center;
}

footer p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.8rem;
    font-weight: 500;
    text-shadow: 0 1px 2px rgba(0,0,0,0.1);
}