/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #0066cc;
    --primary-dark: #0052a3;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --error-color: #dc3545;
    --warning-color: #ffc107;
    --bg-color: #f5f7fa;
    --card-bg: #ffffff;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --border-color: #dee2e6;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: var(--text-primary);
    line-height: 1.6;
}

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

/* Header */
.header {
    text-align: center;
    color: white;
    margin-bottom: 30px;
    padding: 20px;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.1em;
    opacity: 0.95;
}

/* Card */
.card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 40px;
    box-shadow: var(--shadow-lg);
    margin-bottom: 20px;
    animation: slideIn 0.3s ease;
}

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

.card h2 {
    font-size: 1.8em;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.description {
    color: var(--text-secondary);
    margin-bottom: 30px;
    font-size: 1em;
}

/* Steps */
.step {
    display: none;
}

.step.active {
    display: block;
}

/* Form */
.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.95em;
}

.form-group input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1em;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.form-group input.otp-input {
    font-size: 1.5em;
    text-align: center;
    letter-spacing: 0.5em;
    font-weight: 600;
    padding: 15px;
}

.help-text {
    display: block;
    margin-top: 6px;
    font-size: 0.85em;
    color: var(--text-secondary);
}

.attempts-info {
    margin-top: 10px;
    padding: 8px 12px;
    background: #fff3cd;
    border-left: 3px solid var(--warning-color);
    border-radius: 4px;
    font-size: 0.9em;
    color: #856404;
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 102, 204, 0.3);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-secondary {
    background: var(--secondary-color);
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.1em;
}

.btn-link {
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    text-decoration: underline;
    padding: 0;
    font-size: 0.95em;
}

.btn-link:hover {
    color: var(--primary-dark);
}

.btn-icon {
    font-size: 1.2em;
}

.button-group {
    display: flex;
    gap: 12px;
    margin-top: 30px;
}

.button-group .btn {
    flex: 1;
}

/* Success Card */
.success-card {
    text-align: center;
}

.success-icon {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--success-color);
    color: white;
    font-size: 3em;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    animation: scaleIn 0.5s ease;
}

@keyframes scaleIn {
    from {
        transform: scale(0);
    }
    to {
        transform: scale(1);
    }
}

.file-info {
    background: var(--bg-color);
    padding: 20px;
    border-radius: var(--border-radius);
    margin: 20px 0;
    text-align: left;
}

.file-info-item {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px solid var(--border-color);
}

.file-info-item:last-child {
    border-bottom: none;
}

.file-info-label {
    font-weight: 600;
    color: var(--text-secondary);
}

.file-info-value {
    color: var(--text-primary);
}

.security-note {
    margin-top: 20px;
    padding: 15px;
    background: #e7f3ff;
    border-left: 3px solid var(--primary-color);
    border-radius: 4px;
    font-size: 0.9em;
    color: var(--text-secondary);
    text-align: left;
}

/* Resend Section */
.resend-section {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.resend-section p {
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-size: 0.9em;
}

/* Error Message */
.error-message {
    background: #f8d7da;
    color: #721c24;
    padding: 16px 20px;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--error-color);
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
    animation: slideIn 0.3s ease;
}

.error-icon {
    font-size: 1.5em;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    color: white;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

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

.loading-overlay p {
    font-size: 1.1em;
}

/* Footer */
.footer {
    text-align: center;
    color: white;
    margin-top: 40px;
    padding: 20px;
    opacity: 0.9;
}

.footer-note {
    font-size: 0.9em;
    margin-top: 5px;
    opacity: 0.8;
}

/* Responsive */
@media (max-width: 640px) {
    .header h1 {
        font-size: 2em;
    }

    .card {
        padding: 30px 20px;
    }

    .button-group {
        flex-direction: column;
    }

    .button-group .btn {
        width: 100%;
    }
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.mt-20 {
    margin-top: 20px;
}