:root {
    --primary-color: #009efd;
    --secondary-color: #2af598;
    --gradient-1: linear-gradient(180deg, var(--secondary-color) 0%, var(--primary-color) 100%);
    --gradient-2: linear-gradient(45deg, var(--secondary-color), var(--primary-color));
    --text-color: #333;
    --light-text-color: #666;
    --card-bg: rgba(255, 255, 255, 0.9);
    --modal-bg: rgba(255, 255, 255, 0.97);
    --border-color: rgba(255, 255, 255, 0.2);
    --shadow-light: 0 5px 15px rgba(116, 235, 213, 0.4);
    --shadow-medium: 0 10px 30px rgba(0,0,0,0.1);
    --shadow-heavy: 0 15px 40px rgba(99, 102, 241, 0.15);
    --border-radius-sm: 12px;
    --border-radius-md: 24px;
    --border-radius-lg: 30px;
}

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

body {
    font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-image: var(--gradient-1);
    background-size: 200% 200%;
    animation: gradientBG 15s ease infinite;
    min-height: 100vh;
    color: var(--text-color);
    line-height: 1.6;
}

#main {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

.brand {
    text-align: center;
    padding: 40px 0;
    color: #fff;
    animation: fadeInDown 1s ease;
}

.brand-title {
    font-size: 3.5em;
    font-weight: 600;
    margin-bottom: 15px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.brand-flag {
    background: rgba(255,255,255,0.15);
    color: var(--primary-color);
    padding: 8px 25px;
    border-radius: var(--border-radius-lg);
    font-size: 1.1em;
    font-weight: 500;
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
}

.card {
    background: var(--card-bg);
    border-radius: var(--border-radius-md);
    padding: 30px;
    margin-bottom: 25px;
    box-shadow: var(--shadow-medium);
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
    animation: fadeInUp 0.8s ease;
    animation-fill-mode: both;
    border: 1px solid var(--border-color);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-heavy);
}

.button-group {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
    padding: 20px;
    max-width: 100%;
}

.enter-button {
    background: var(--gradient-2);
    color: white;
    padding: 16px 20px;
    border-radius: var(--border-radius-lg);
    text-decoration: none;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: 500;
    font-size: 1.1em;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-light);
    width: 100%;
    text-align: center;
}

.enter-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(159, 172, 230, 0.5);
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
}

.title {
    color: var(--primary-color);
    font-size: 1.4em;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
}

.title::before {
    content: "";
    width: 4px;
    height: 25px;
    background: linear-gradient(to bottom, var(--secondary-color), var(--primary-color));
    display: inline-block;
    border-radius: 4px;
}

.link-list {
    list-style: none;
}

.link-list li {
    margin: 12px 0;
    line-height: 1.8;
    transition: all 0.3s ease;
    padding: 12px 20px;
    border-radius: var(--border-radius-sm);
    background: rgba(255,255,255,0.5);
}

.link-list li:hover {
    background: rgba(102,126,234,0.1);
    transform: translateX(5px);
}

.link-list a {
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
}

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

.tip-item {
    background: rgba(255,255,255,0.5);
    padding: 20px;
    border-radius: 16px;
    margin: 15px 0;
    border: 1px solid var(--border-color);
}

.browser-tip {
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 12px 0;
    padding: 8px 0;
    color: var(--light-text-color);
}

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

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

.card:nth-child(2) { animation-delay: 0.2s; }
.card:nth-child(3) { animation-delay: 0.4s; }
.card:nth-child(4) { animation-delay: 0.6s; }
.card:nth-child(5) { animation-delay: 0.8s; }

@media (max-width: 768px) {
    #main { padding: 15px; }
    .brand-title { font-size: 2.5em; }
    .card { padding: 20px; }
    .button-group {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
        padding: 15px;
    }
    .enter-button {
        padding: 12px 15px;
        font-size: 1em;
    }
    .link-list li { padding: 10px 15px; }
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* Modal Styles (Notice & Music) */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    backdrop-filter: blur(10px);
    animation: modalFadeIn 0.4s ease;
}

.modal-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--modal-bg);
    padding: 40px;
    border-radius: var(--border-radius-md);
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    max-width: 90%;
    width: 420px;
    text-align: center;
    animation: modalPop 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.close-modal {
    position: absolute;
    right: 20px;
    top: 15px;
    font-size: 24px;
    cursor: pointer;
    color: var(--light-text-color);
    transition: all 0.3s ease;
}

.close-modal:hover {
    color: #b21f1f;
    transform: rotate(90deg);
}

.notice-title {
    font-size: 2em;
    color: var(--primary-color);
    margin-bottom: 25px;
    font-weight: 600;
    background: var(--gradient-2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.notice-text {
    line-height: 2;
    color: #34495e;
    font-size: 1.15em;
    margin-bottom: 30px;
}

.notice-text p {
    margin: 10px 0;
    opacity: 0;
    transform: translateY(10px);
    animation: textFadeIn 0.4s ease forwards;
}

.notice-text p:nth-child(1) { animation-delay: 0.1s; }
.notice-text p:nth-child(2) { animation-delay: 0.2s; }
.notice-text p:nth-child(3) { animation-delay: 0.3s; }
.notice-text p:nth-child(4) { animation-delay: 0.4s; }

.notice-btn {
    background: var(--gradient-2);
    color: white;
    border: none;
    padding: 15px 45px;
    border-radius: var(--border-radius-lg);
    font-size: 1.1em;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-light);
    transform: translateY(10px);
    animation: buttonPop 0.4s 0.5s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    opacity: 0;
}

.notice-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(159, 172, 230, 0.4);
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
}

@keyframes modalFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes modalPop {
    0% { transform: translate(-50%, -50%) scale(0.9); opacity: 0; }
    100% { transform: translate(-50%, -50%) scale(1); opacity: 1; }
}

@keyframes textFadeIn {
    to { opacity: 1; transform: translateY(0); }
}

@keyframes buttonPop {
    to { opacity: 1; transform: translateY(0); }
}

/* Removed: Music Prompt Styles (.music-prompt, .music-prompt.show, etc.) */
/* Removed: Fixed Music Control Button Styles (#musicControl, #musicControl.paused) */

/* General Utility Classes */
.text-center { text-align: center; }
.mt-10 { margin-top: 10px; }
.mt-20 { margin-top: 20px; }
.color-light { color: var(--light-text-color); }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-gap-10 { display: flex; gap: 10px; }
.p-15 { padding: 15px; }