/* Google Fonts loaded via <link> in HTML head for better performance */

/* Visually hidden but accessible to screen readers and crawlers */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

:root {
    --bg-gradient-start: #f0f2f5;
    --bg-gradient-end: #d9e2f1;
    --font-color: #333;
    --container-bg: rgba(255, 255, 255, 0.6);
    --container-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --heading-color: #2c3e50;
    --result-color: #3498db;
    --category-color: #95a5a6;
    --category-border: #bdc3c7;
    --button-bg: #3498db;
    --button-hover-bg: #2980b9;
    --button-shadow: rgba(52, 152, 219, 0.4);
    --control-bg: rgba(255, 255, 255, 0.7);
    --control-btn-color: #7f8c8d;
    --control-btn-active-bg: #3498db;
    --control-btn-active-color: white;
}

body[data-theme='dark'] {
    --bg-gradient-start: #232526;
    --bg-gradient-end: #414345;
    --font-color: #ecf0f1;
    --container-bg: rgba(44, 62, 80, 0.7);
    --container-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    --heading-color: #ecf0f1;
    --result-color: #5dade2;
    --category-color: #95a5a6;
    --category-border: #7f8c8d;
    --button-bg: #5dade2;
    --button-hover-bg: #85c1e9;
    --button-shadow: rgba(93, 173, 226, 0.4);
    --control-bg: rgba(52, 73, 94, 0.7);
    --control-btn-color: #bdc3c7;
    --control-btn-active-bg: #5dade2;
    --control-btn-active-color: #2c3e50;
}

body {
    font-family: 'Poppins', 'Noto Sans KR', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background: linear-gradient(120deg, var(--bg-gradient-start), var(--bg-gradient-end));
    color: var(--font-color);
    transition: background-color 0.3s, color 0.3s;
}

.container {
    text-align: center;
    background: var(--container-bg);
    padding: 40px 50px;
    border-radius: 20px;
    box-shadow: var(--container-shadow);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    width: 90%;
    max-width: 600px;
}

h1 {
    font-weight: 700;
    font-size: 2.5em;
    color: var(--heading-color);
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.1em;
    color: var(--category-color);
    margin-bottom: 30px;
    font-weight: 400;
}

.roulette-container {
    margin: 30px 0;
    padding: 20px;
    border: 2px dashed var(--category-border);
    border-radius: 10px;
    min-height: 100px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.result {
    font-size: 1.8em;
    font-weight: 700;
    color: var(--result-color);
    animation: fadeIn 0.5s ease-in-out;
}

#result-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

#result-category {
    font-size: 1.1em;
    font-weight: 600;
    color: var(--category-color);
    margin: 0;
    margin-bottom: 15px;
    border: 1px solid var(--category-border);
    border-radius: 20px;
    padding: 5px 15px;
    display: none;
}

#spinButton {
    background: var(--button-bg);
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 1.2em;
    font-weight: 700;
    border-radius: 50px;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    box-shadow: 0 4px 15px var(--button-shadow);
}

#spinButton:hover {
    background-color: var(--button-hover-bg);
}

#spinButton:active {
    transform: scale(0.95);
}

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

/* Header Controls */
.controls-header {
    position: absolute;
    top: 20px;
    right: 30px;
    display: flex;
    align-items: center;
    gap: 20px;
    background: var(--control-bg);
    padding: 10px 20px;
    border-radius: 50px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: var(--container-shadow);
}

.lang-controls {
    display: flex;
    background-color: rgba(127, 140, 141, 0.2);
    border-radius: 20px;
    overflow: hidden;
}

.lang-btn {
    background: transparent;
    border: none;
    color: var(--control-btn-color);
    padding: 8px 12px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9em;
    transition: background-color 0.3s, color 0.3s;
}

.lang-btn.active {
    background-color: var(--control-btn-active-bg);
    color: var(--control-btn-active-color);
    border-radius: 20px;
}

/* Theme-toggle */
.theme-switch-wrapper {
    display: flex;
    align-items: center;
}

.theme-switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 28px;
}

.theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 20px;
    width: 20px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: .4s;
}

input:checked + .slider {
    background-color: #2196F3;
}

input:checked + .slider:before {
    transform: translateX(22px);
}

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}

/* Noscript SEO Content */
.seo-content {
    max-width: 600px;
    margin: 20px auto;
    padding: 20px;
    text-align: left;
    color: var(--font-color);
}

.seo-content h2 {
    font-size: 1.5em;
    color: var(--heading-color);
    margin: 20px 0 10px;
}

.seo-content h3 {
    font-size: 1.2em;
    color: var(--heading-color);
    margin: 15px 0 8px;
}

.seo-content ul {
    padding-left: 20px;
}

.seo-content li {
    margin: 5px 0;
}

/* Footer */
footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    text-align: center;
    padding: 15px;
    font-size: 0.85em;
    color: var(--category-color);
}

footer p {
    margin: 0;
}

/* Responsive Design - Media Queries */
@media screen and (max-width: 768px) {
    h1 {
        font-size: 1.8em;
    }

    .subtitle {
        font-size: 0.95em;
    }

    .container {
        padding: 30px 25px;
        width: 92%;
    }

    .result {
        font-size: 1.4em;
    }

    .roulette-container {
        margin: 20px 0;
        padding: 15px;
        min-height: 80px;
    }

    #spinButton {
        padding: 12px 25px;
        font-size: 1.1em;
    }

    .controls-header {
        top: 10px;
        right: 10px;
        padding: 8px 15px;
        gap: 12px;
    }

    .lang-btn {
        padding: 6px 10px;
        font-size: 0.8em;
    }

    .theme-switch {
        width: 44px;
        height: 24px;
    }

    .slider:before {
        height: 18px;
        width: 18px;
        left: 3px;
        bottom: 3px;
    }

    input:checked + .slider:before {
        transform: translateX(20px);
    }

    footer {
        padding: 10px;
        font-size: 0.75em;
    }
}

@media screen and (max-width: 480px) {
    h1 {
        font-size: 1.5em;
    }

    .subtitle {
        font-size: 0.85em;
    }

    .container {
        padding: 25px 18px;
        width: 95%;
        border-radius: 15px;
    }

    .result {
        font-size: 1.2em;
    }

    #result-category {
        font-size: 0.95em;
        padding: 4px 12px;
    }

    #spinButton {
        padding: 10px 22px;
        font-size: 1em;
    }

    .controls-header {
        top: 8px;
        right: 8px;
        padding: 6px 12px;
        gap: 8px;
        border-radius: 30px;
    }
}

@media screen and (min-width: 1200px) {
    .container {
        max-width: 700px;
        padding: 50px 60px;
    }

    h1 {
        font-size: 2.8em;
    }

    .result {
        font-size: 2em;
    }
}

/* Print styles */
@media print {
    .controls-header,
    #spinButton,
    .theme-switch-wrapper {
        display: none;
    }

    body {
        background: white;
        color: black;
    }

    .container {
        box-shadow: none;
        border: none;
        backdrop-filter: none;
    }
}