@import url('https://fonts.googleapis.com/css?family=Roboto:300,400,500,700&display=swap');

* {
    box-sizing: border-box;
}

body {
    font-family: 'Roboto', sans-serif;
    background: #f4f5f7;
    margin: 0;
    padding: 20px;
    color: #1f2933;
}

.container {
    max-width: 960px;
    margin: 0 auto;
}

.row {
    display: flex;
    flex-wrap: wrap;
}

.col-md-12 {
    width: 100%;
}

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

.mb-5 {
    margin-bottom: 3rem;
}

.mt-5 {
    margin-top: 3rem;
}

.captcha-wrapper {
    display: flex;
    justify-content: center;
    padding: 0 15px;
}

.slidercaptcha {
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 12px 24px rgba(15, 23, 42, 0.12);
    width: 100%;
    max-width: 360px;
    overflow: hidden;
    transition: transform 0.3s ease;
}

.slidercaptcha:hover {
    transform: translateY(-2px);
}

.card-header {
    background: #3b82f6;
    color: #ffffff;
    padding: 16px 20px;
    font-weight: 500;
    position: relative;
}

.refresh-btn {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.18);
    border: none;
    color: #ffffff;
    padding: 8px 10px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.refresh-btn:hover {
    background: rgba(255, 255, 255, 0.28);
}

.card-body {
    padding: 20px;
}

.captcha-container {
    position: relative;
    width: 100%;
    max-width: 300px;
    margin: 0 auto;
}

#captchaCanvas {
    width: 100%;
    height: 200px;
    border-radius: 10px;
    border: 2px solid #d7dee4;
    background: #f9fafc;
    display: block;
}

#puzzleCanvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 60px;
    height: 60px;
    z-index: 2;
    transition: left 0.2s ease;
}

.slider-track {
    position: relative;
    margin-top: 16px;
    height: 50px;
    border-radius: 25px;
    border: 2px solid #d7dee4;
    background: #f9fafc;
    overflow: hidden;
}

.slider-progress {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, #60a5fa 0%, #3b82f6 100%);
    transition: width 0.1s ease-out;
    border-radius: 23px;
}

.slider-button {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    background: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #4b5563;
    font-size: 16px;
    box-shadow: 0 4px 12px rgba(15, 23, 42, 0.12);
    cursor: grab;
    user-select: none;
    z-index: 3;
    transition: left 0.1s ease-out, transform 0.2s ease;
}

.slider-button:active {
    cursor: grabbing;
    transform: scale(1.05);
}

.slider-button.dragging {
    transition: none;
}

.slider-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #6b7280;
    font-size: 14px;
    pointer-events: none;
    transition: opacity 0.2s ease;
    z-index: 1;
}

.slider-button.dragging + .slider-text {
    opacity: 0;
}

.captcha-container.success .slider-track {
    border-color: #22c55e;
    background: #ecfdf3;
}

.captcha-container.success .slider-progress {
    background: linear-gradient(90deg, #22c55e 0%, #16a34a 100%);
}

.captcha-container.success .slider-button {
    background: #22c55e;
    color: #ffffff;
}

.captcha-container.error .slider-track {
    border-color: #ef4444;
    background: #fef2f2;
    animation: shake 0.4s ease-in-out;
}

.captcha-container.error .slider-progress {
    background: linear-gradient(90deg, #ef4444 0%, #dc2626 100%);
}

.captcha-container.error .slider-button {
    background: #ef4444;
    color: #ffffff;
}

.status-line {
    margin-top: 12px;
    font-size: 13px;
    color: #6b7280;
    text-align: center;
    min-height: 18px;
}

.loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(59, 130, 246, 0.25), transparent);
    animation: loading 1.4s infinite;
}

@keyframes loading {
    0% { left: -100%; }
    100% { left: 100%; }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-6px); }
    75% { transform: translateX(6px); }
}

@media (max-width: 480px) {
    .slidercaptcha {
        max-width: 320px;
    }

    #captchaCanvas {
        height: 170px;
    }

    .slider-track {
        height: 45px;
    }

    .slider-button {
        width: 40px;
        height: 40px;
    }
}