@font-face {
    font-family: 'MyCustomFont';
    src: url('font.ttf') format('truetype');
}

:root {
    --font-family-sans: 'MyCustomFont', 'Roboto', sans-serif;
    --motion-easing: cubic-bezier(0.4, 0, 0.2, 1);
    --motion-duration: 0.5s;
    /* Light Theme */
    --md-sys-color-primary-light: #0B57D0; --md-sys-color-on-primary-light: #FFFFFF;
    --md-sys-color-primary-container-light: #D8E2FF; --md-sys-color-on-primary-container-light: #001A41;
    --md-sys-color-background-light: #F8F9FC; --md-sys-color-on-background-light: #1A1C1E;
    --md-sys-color-surface-variant-light: #E1E2EC; --md-sys-color-on-surface-variant-light: #44474F;
    --md-sys-color-outline-light: #74777F; --md-sys-color-surface-container-low-light: #F2F3F7;
    --state-layer-color: #0B57D0;

    /* Dark Theme */
    --md-sys-color-primary-dark: #A8C7FA; --md-sys-color-on-primary-dark: #203148;
    --md-sys-color-primary-container-dark: #374860; --md-sys-color-on-primary-container-dark: #D8E2FF;
    --md-sys-color-background-dark: #1A1C1E; --md-sys-color-on-background-dark: #E3E2E6;
    --md-sys-color-surface-variant-dark: #44474F; --md-sys-color-on-surface-variant-dark: #C4C6CF;
    --md-sys-color-outline-dark: #8E9099; --md-sys-color-surface-container-low-dark: #202225;
    --state-layer-color-dark: #A8C7FA;
}

@media (prefers-color-scheme: light) {
    :root {
        --app-bg: var(--md-sys-color-background-light); --text-primary: var(--md-sys-color-on-background-light);
        --text-secondary: var(--md-sys-color-on-surface-variant-light); --sidebar-bg: var(--md-sys-color-surface-container-low-light);
        --search-bg: var(--md-sys-color-surface-variant-light); --song-list-hover-bg: var(--md-sys-color-surface-variant-light);
        --fab-bg: var(--md-sys-color-primary-light); --fab-icon: var(--md-sys-color-on-primary-light);
        --icon-button-color: var(--md-sys-color-on-surface-variant-light); --icon-button-active-bg: var(--md-sys-color-primary-container-light);
        --icon-button-active-color: var(--md-sys-color-on-primary-container-light); --progress-track-bg: var(--md-sys-color-surface-variant-light);
        --progress-thumb-bg: var(--md-sys-color-primary-light); --cover-bg: var(--md-sys-color-primary-container-light);
        --mobile-nav-bg: #F8F9FC; --mobile-nav-border: var(--md-sys-color-outline-light);
        --state-layer: var(--state-layer-color);
    }
}

@media (prefers-color-scheme: dark) {
    :root {
        --app-bg: var(--md-sys-color-background-dark); --text-primary: var(--md-sys-color-on-background-dark);
        --text-secondary: var(--md-sys-color-on-surface-variant-dark); --sidebar-bg: var(--md-sys-color-surface-container-low-dark);
        --search-bg: var(--md-sys-color-surface-variant-dark); --song-list-hover-bg: var(--md-sys-color-surface-variant-dark);
        --fab-bg: var(--md-sys-color-primary-dark); --fab-icon: var(--md-sys-color-on-primary-dark);
        --icon-button-color: var(--md-sys-color-on-surface-variant-dark); --icon-button-active-bg: var(--md-sys-color-primary-container-dark);
        --icon-button-active-color: var(--md-sys-color-on-primary-container-dark); --progress-track-bg: var(--md-sys-color-surface-variant-dark);
        --progress-thumb-bg: var(--md-sys-color-primary-dark); --cover-bg: var(--md-sys-color-primary-container-dark);
        --mobile-nav-bg: #1A1C1E; --mobile-nav-border: var(--md-sys-color-outline-dark);
        --state-layer: var(--state-layer-color-dark);
    }
}

body { font-family: var(--font-family-sans); margin: 0; height: 100vh; width: 100vw;
    background-color: var(--app-bg); color: var(--text-primary); overflow: hidden;
}
.material-symbols-outlined { font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24; transition: font-variation-settings 0.3s ease; }
.app-container { height: 100%; width: 100%; display: flex; position: relative; overflow: hidden; }

/* --- Sidebar --- */
.sidebar {
    background-color: var(--sidebar-bg); display: flex; flex-direction: column;
    box-sizing: border-box; height: 100%; width: 320px; border-right: 1px solid var(--mobile-nav-border);
    flex-shrink: 0;
}
.sidebar-content { flex-grow: 1; display: flex; flex-direction: column; padding: 16px; overflow: hidden; }
.sidebar-footer { flex-shrink: 0; padding: 0 16px 16px; border-top: 1px solid var(--mobile-nav-border); }
.sidebar-header { display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 0 8px 16px; }
.close-sidebar-btn { display: none; }
.sidebar-title { font-size: 24px; font-weight: 500; margin: 0; }
.search-container { display: flex; align-items: center; background-color: var(--search-bg); border-radius: 28px; padding: 0 16px; margin-bottom: 16px; }
#search { flex-grow: 1; border: none; background: transparent; color: var(--text-primary); padding: 14px 8px; font-size: 16px; outline: none; }
.song-list { list-style: none; padding: 0; margin: 0; overflow-y: auto; flex-grow: 1; }
.song-list li { display: flex; align-items: center; padding: 12px 16px; margin-bottom: 4px; border-radius: 12px; cursor: pointer; transition: background-color 0.2s; }
#settings-list { padding-top: 16px; flex-grow: 0; }
.song-list li:hover { background-color: var(--song-list-hover-bg); }
.song-list li.active { background-color: var(--icon-button-active-bg); }
.home-list-item, .settings-list-item { font-weight: 500; }
.home-list-item .material-symbols-outlined, .settings-list-item .material-symbols-outlined { margin-right: 16px; color: var(--fab-bg); }
.settings-list-item .material-symbols-outlined { font-variation-settings: 'FILL' 0; }

/* --- Contenuto Principale e Viste --- */
.main-content { flex-grow: 1; height: 100%; display: grid; place-items: center; position: relative; }
.view {
    grid-area: 1 / 1; width: 100%; height: 100%; display: flex; flex-direction: column;
    align-items: center; justify-content: center; padding: 24px; box-sizing: border-box;
    transition: opacity var(--motion-duration) var(--motion-easing), transform var(--motion-duration) var(--motion-easing);
}
.view.hidden { opacity: 0; pointer-events: none; transform: scale(0.95); }
.home-icon-container { width: 120px; height: 120px; background: var(--cover-bg); border-radius: 50%; display: grid; place-items: center; margin-bottom: 24px; }
.home-icon-container .material-symbols-outlined { font-size: 64px; color: var(--text-primary); }
#home-view h1 { font-size: 2em; font-weight: 500; }
#username:focus { background-color: var(--search-bg); outline: none; border-radius: 8px; padding: 2px 6px; }
.player-content { display: flex; flex-direction: column; align-items: center; width: 100%; max-width: 400px; }
.song-image { width: clamp(200px, 40vh, 320px); aspect-ratio: 1 / 1; overflow: hidden; margin-bottom: 24px; background-color: var(--cover-bg); box-shadow: 0 8px 24px rgba(0,0,0,0.1); transition: transform 0.3s ease; border-radius: 24px; }
.song-image:active { transform: scale(0.98); }
.song-image img { width: 100%; height: 100%; object-fit: cover; }
.song-details { text-align: center; margin-bottom: 16px; }
.song-details h2 { font-size: 22px; margin: 0 0 4px; }
.song-details p { font-size: 16px; color: var(--text-secondary); margin: 0; }
.progress-container { width: 100%; margin-bottom: 16px; }
#progress-bar {
    -webkit-appearance: none; appearance: none;
    width: 100%; height: 4px; background: var(--progress-track-bg);
    border-radius: 2px; outline: none; cursor: pointer;
    background-image: linear-gradient(var(--progress-thumb-bg), var(--progress-thumb-bg));
    background-size: 0% 100%; background-repeat: no-repeat;
}
#progress-bar::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 4px; height: 16px; background: var(--progress-thumb-bg); border-radius: 2px; border: none; }
#progress-bar::-moz-range-thumb { width: 4px; height: 16px; background: var(--progress-thumb-bg); border-radius: 2px; border: none; }
.time-labels { display: flex; justify-content: space-between; font-size: 12px; color: var(--text-secondary); margin-top: 8px; padding: 0 2px; }
.controls { display: flex; align-items: center; justify-content: center; gap: 8px; width: 100%; }
.icon-button { position: relative; overflow: hidden; border: none; background: transparent; color: var(--icon-button-color); width: 48px; height: 48px; display: grid; place-items: center; cursor: pointer; transition: background-color 0.2s; border-radius: 50%; }
.icon-button::before, .fab::before { content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 100%; border-radius: inherit; background-color: var(--state-layer); opacity: 0; transform: scale(0); transition: transform 0.3s, opacity 0.3s; }
.icon-button:hover::before, .fab:hover::before { transform: scale(1); opacity: 0.08; }
.icon-button:active::before, .fab:active::before { transform: scale(1); opacity: 0.12; }
.icon-button.active { background-color: var(--icon-button-active-bg); color: var(--icon-button-active-color); }
.icon-button.active .material-symbols-outlined, .fab .material-symbols-outlined { font-variation-settings: 'FILL' 1; }
.fab { position: relative; overflow: hidden; border: none; background-color: var(--fab-bg); color: var(--fab-icon); width: 64px; height: 64px; display: grid; place-items: center; cursor: pointer; box-shadow: 0 4px 12px rgba(0,0,0,0.15); border-radius: 50%; transition: background-color 0.2s, border-radius 0.5s var(--motion-easing); }
.fab.is-playing { border-radius: 20px; }
.fab .material-symbols-outlined { font-size: 36px; }

/* --- Popup Informazioni --- */
.fullscreen-view { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(0,0,0,0.3); z-index: 1100; display: flex; justify-content: center; align-items: center; opacity: 0; pointer-events: none; transition: opacity var(--motion-duration) var(--motion-easing); }
.fullscreen-view.visible { opacity: 1; pointer-events: auto; }
.popup-content { background-color: var(--sidebar-bg); border-radius: 28px; width: 90%; max-width: 500px; display: flex; flex-direction: column; padding: 24px; box-shadow: 0 8px 24px rgba(0,0,0,0.15); transform: scale(0.95); transition: transform var(--motion-duration) var(--motion-easing); }
.fullscreen-view.visible .popup-content { transform: scale(1); }
.page-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; }
.page-header h2 { margin: 0; font-size: 22px; }
.page-content { flex-grow: 1; overflow-y: auto; }
.info-section { margin-bottom: 24px; }
.info-section h3 { margin: 0 0 8px; }
.info-section p { margin: 0; color: var(--text-secondary); line-height: 1.6; }
.popup-footer { display: flex; justify-content: center; align-items: center; gap: 24px; padding-top: 16px; border-top: 1px solid var(--mobile-nav-border); }
.social-icon { height: 28px; opacity: 0.7; transition: opacity 0.2s; }
.social-icon:hover { opacity: 1; }

/* --- Easter Egg & Overlay --- */
#easter-egg-container { position: fixed; top: 0; left: 0; width: 100%; height: 100%; pointer-events: none; overflow: hidden; z-index: 9999; }
.heart-emoji { position: absolute; font-size: 48px; animation: floatUp 4s ease-in-out forwards; }
@keyframes floatUp { 0% { transform: translateY(0) scale(1); opacity: 1; } 100% { transform: translateY(-200px) scale(0.5); opacity: 0; } }
.sidebar-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background-color: rgba(0,0,0,0.4); z-index: 1001; opacity: 0; transition: opacity 0.3s ease; }
.sidebar-open .sidebar-overlay { display: block; opacity: 1; }
.mobile-nav { display: none; }

/* --- Media Query per Mobile --- */
@media (max-width: 768px) {
    .app-container { flex-direction: column; padding-bottom: 80px; }
    .sidebar {
        position: fixed; top: 0; left: 0; height: 100%; z-index: 1002;
        transform: translateX(-100%); transition: transform var(--motion-duration) var(--motion-easing);
        border-right: none; width: 85%; max-width: 320px;
    }
    .sidebar-open .sidebar { transform: translateX(0); box-shadow: 0 8px 10px -5px rgba(0,0,0,0.2), 0 16px 24px 2px rgba(0,0,0,0.14), 0 6px 30px 5px rgba(0,0,0,0.12); }
    .close-sidebar-btn { display: grid; }
    .home-list-item { display: none; }
    .mobile-nav {
        display: flex; position: fixed; bottom: 0; left: 0; right: 0; height: 80px;
        background-color: var(--mobile-nav-bg); border-top: 1px solid var(--mobile-nav-border);
        justify-content: space-around; z-index: 1000; padding: 0 8px; box-sizing: border-box;
        padding-bottom: env(safe-area-inset-bottom);
    }
    .nav-item { display: flex; flex-direction: column; align-items: center; justify-content: center; background: none; border: none; color: var(--icon-button-color); flex-grow: 1; flex-basis: 0; height: 56px; border-radius: 28px; margin: auto 4px; transition: background-color 0.2s, color 0.2s; position: relative; overflow: hidden; }
    .nav-item::before { content: ''; position: absolute; top: 50%; left: 50%; width: 150%; padding-top: 150%; border-radius: 50%; background-color: var(--state-layer); opacity: 0; transform: translate(-50%, -50%) scale(0); transition: transform 0.4s, opacity 0.4s; }
    .nav-item:active::before { transform: translate(-50%, -50%) scale(1); opacity: 0.12; }
    .nav-item .material-symbols-outlined { font-size: 24px; margin-bottom: 4px; }
    .nav-label { font-size: 12px; transition: font-weight 0.2s; }
    .nav-item.active .material-symbols-outlined { font-variation-settings: 'FILL' 1; }
    .nav-item.active .nav-label { font-weight: 700; }
    .nav-item.active { color: var(--text-primary); background-color: var(--icon-button-active-bg); }
}