/* ============================================================
   QuizHub — CSS
   ============================================================ */

/* ── Tokens ── */
:root {
    --bg:       #07080f;
    --bg2:      #0d0e1a;
    --surface:  #111224;
    --surface2: #181930;
    --border:   rgba(255,255,255,0.07);
    --border2:  rgba(255,255,255,0.13);
    --text:     #e8eaf6;
    --text2:    #6e7191;
    --text3:    #3d3f5a;
    --primary:  #7c3aed;
    --radius:   16px;
    --ease:     cubic-bezier(.4,0,.2,1);
    --t:        180ms;

    --c-word:      #22c55e;
    --c-math:      #f43f5e;
    --c-logic:     #a78bfa;
    --c-geography: #06b6d4;
    --c-gaming:    #38bdf8;
    --c-music:     #f472b6;
    --c-movie:     #fb923c;
    --c-sport:     #facc15;
    --c-history:   #f97316;
    --c-trivia:    #60a5fa;
    --c-other:     #94a3b8;
    --c-fav:       #f43f5e;
}

[data-theme="light"] {
    --bg:       #f0f2fa;
    --bg2:      #e4e7f5;
    --surface:  #ffffff;
    --surface2: #f4f5fd;
    --border:   rgba(0,0,0,0.07);
    --border2:  rgba(0,0,0,0.12);
    --text:     #0f1023;
    --text2:    #5a5d80;
    --text3:    #b0b3cc;
}

/* ── Accessibility / SEO ── */
.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;
}

/* ── Page tagline (H1 SEO visible) ── */
.page-tagline {
    text-align: center;
    font-size: .85rem;
    font-weight: 500;
    color: var(--text3);
    margin: .5rem 1rem 1rem;
    letter-spacing: .01em;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
    font-family: 'Inter', system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100dvh;
    display: flex;
    flex-direction: column;
    transition: background var(--t), color var(--t);
}
a { color: inherit; text-decoration: none; }
button { cursor: pointer; font-family: inherit; border: none; background: none; }

/* ============================================================
   HEADER
   ============================================================ */
#header {
    position: sticky;
    top: 0;
    z-index: 200;
    background: color-mix(in srgb, var(--bg) 82%, transparent);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border-bottom: 1px solid var(--border);
}

/* ── Top bar ── */
.topbar {
    display: flex;
    align-items: center;
    gap: 1rem;
    max-width: 1500px;
    margin: 0 auto;
    padding: 0.7rem 1.5rem;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-shrink: 0;
    text-decoration: none;
    color: var(--text);
    font-size: 1.25rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    line-height: 1;
}
.logo .fa-brain {
    font-size: 1.3rem;
    background: linear-gradient(135deg, #7c3aed, #2563eb);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.logo strong {
    background: linear-gradient(135deg, #7c3aed, #2563eb);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Search field */
.search-field {
    flex: 1;
    max-width: 560px;
    margin: 0 auto;
    position: relative;
    display: flex;
    align-items: center;
}
.search-field .fa-search {
    position: absolute;
    left: 14px;
    color: var(--text3);
    font-size: 0.8rem;
    pointer-events: none;
    z-index: 1;
}
#searchInput {
    width: 100%;
    padding: 0.58rem 2.6rem 0.58rem 2.4rem;
    background: var(--surface);
    border: 1.5px solid var(--border2);
    border-radius: 999px;
    color: var(--text);
    font-size: 0.875rem;
    font-family: inherit;
    outline: none;
    transition: border-color var(--t), box-shadow var(--t);
}
#searchInput::placeholder { color: var(--text3); }
#searchInput:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(124,58,237,0.15);
}
.clear-btn {
    position: absolute;
    right: 10px;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--border2);
    color: var(--text2);
    font-size: 0.7rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--t), color var(--t);
}
.clear-btn:hover { background: var(--text3); color: var(--text); }

/* Topbar actions */
.topbar-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-shrink: 0;
}

/* Language toggle */
.lang-toggle {
    display: flex;
    background: var(--surface);
    border: 1.5px solid var(--border2);
    border-radius: 999px;
    overflow: hidden;
    padding: 2px;
    gap: 2px;
}
.lang-btn {
    padding: 0.25rem 0.55rem;
    border-radius: 999px;
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--text2);
    letter-spacing: 0.5px;
    transition: all var(--t);
}
.lang-btn.active {
    background: var(--primary);
    color: #fff;
}
.lang-btn:not(.active):hover { color: var(--text); }

/* Icon button (theme) */
.icon-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--surface);
    border: 1.5px solid var(--border2);
    color: var(--text2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
    transition: all var(--t);
}
.icon-btn:hover { border-color: var(--primary); color: var(--primary); }

/* ── Filter bar ── */
.filterbar {
    max-width: 1500px;
    margin: 0 auto;
    padding: 0 1.5rem 0.55rem;
    border-top: 1px solid var(--border);
}

.cats-scroll {
    display: flex;
    gap: 0.3rem;
    overflow-x: auto;
    scrollbar-width: none;
    min-width: 0;
    padding: 0.5rem 0 0.25rem;
}
.cats-scroll::-webkit-scrollbar { display: none; }

.cat-pill {
    display: flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.3rem 0.75rem;
    border-radius: 999px;
    border: 1.5px solid var(--border2);
    color: var(--text2);
    font-size: 0.78rem;
    font-weight: 500;
    white-space: nowrap;
    transition: all var(--t);
    flex-shrink: 0;
}
.cat-pill em {
    font-style: normal;
    font-size: 0.68rem;
    font-weight: 700;
    background: var(--border2);
    border-radius: 999px;
    padding: 0 5px;
    min-width: 16px;
    text-align: center;
    line-height: 1.6;
}
.cat-pill:hover { border-color: var(--text2); color: var(--text); }
.cat-pill.active {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff;
    font-weight: 600;
}
.cat-pill.active em { background: rgba(255,255,255,0.22); color: #fff; }

/* Fav pill */
.cat-pill--fav .fa-heart { font-size: 0.7rem; }
.cat-pill--fav.has-items { border-color: var(--c-fav); color: var(--c-fav); }
.cat-pill--fav.has-items em { background: rgba(244,63,94,0.15); color: var(--c-fav); }
.cat-pill--fav.has-items.active { background: var(--c-fav); border-color: var(--c-fav); color: #fff; }
.cat-pill--fav.has-items.active em { background: rgba(255,255,255,0.22); color: #fff; }

/* Open selected button */
.open-selected-btn {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.38rem 0.9rem;
    background: var(--primary);
    color: #fff;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 600;
    flex-shrink: 0;
    transition: all var(--t);
}
.open-selected-btn strong {
    background: rgba(255,255,255,0.22);
    border-radius: 999px;
    padding: 0 6px;
    min-width: 18px;
    text-align: center;
    font-size: 0.72rem;
    line-height: 1.6;
    display: inline-block;
}
.open-selected-btn:disabled { opacity: 0.35; cursor: not-allowed; }
.open-selected-btn:not(:disabled):hover {
    background: #6d28d9;
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(124,58,237,0.35);
}
.open-selected-btn .fa-external-link-alt { font-size: 0.75rem; }

/* ============================================================
   MAIN
   ============================================================ */
main {
    max-width: 1500px;
    margin: 0 auto;
    padding: 1.5rem 1.5rem 4rem;
    flex: 1;
    width: 100%;
}

.section-hd {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}
.section-hd h2 {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--text2);
    text-transform: uppercase;
    letter-spacing: 0.9px;
}
.section-hd-right {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.sort-group {
    display: flex;
    gap: 2px;
    background: var(--surface);
    border: 1.5px solid var(--border2);
    border-radius: 999px;
    padding: 2px;
}
.sort-btn {
    padding: 0.2rem 0.55rem;
    border-radius: 999px;
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text2);
    white-space: nowrap;
    transition: all var(--t);
}
.sort-btn.active {
    background: var(--primary);
    color: #fff;
}
.sort-btn:not(.active):hover { color: var(--text); }
.featured-section .section-hd h2 {
    font-size: 1rem;
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: linear-gradient(90deg, #f97316, #f43f5e);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-transform: none;
    letter-spacing: normal;
}
.count-badge {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text2);
    background: var(--surface);
    border: 1px solid var(--border2);
    border-radius: 999px;
    padding: 0.18rem 0.6rem;
}
.collapse-btn {
    color: var(--text2);
    font-size: 0.85rem;
    transition: color var(--t), transform 0.3s;
    padding: 4px;
}
.collapse-btn:hover { color: var(--text); }
.featured-section.collapsed .collapse-btn { transform: rotate(180deg); }

/* ── Featured section ── */
.featured-section {
    margin-bottom: 2rem;
    background: color-mix(in srgb, #f97316 5%, var(--surface));
    border: 1px solid rgba(249,115,22,0.25);
    border-radius: 20px;
    padding: 1.1rem 1.25rem 1.25rem;
    position: relative;
    overflow: hidden;
    box-shadow: 0 0 0 1px rgba(249,115,22,0.08), 0 4px 20px rgba(249,115,22,0.06);
}
/* strip colorata a sinistra */
.featured-section::before {
    content: '';
    position: absolute;
    left: 0; top: 0; bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, #f97316, #f43f5e, #7c3aed);
    border-radius: 3px 0 0 3px;
}
[data-theme="light"] .featured-section {
    background: color-mix(in srgb, #f97316 4%, #fff);
    border-color: rgba(249,115,22,0.2);
}
.featured-section .section-hd {
    margin-bottom: 0.9rem;
    cursor: pointer;
}
.featured-section.collapsed { padding-bottom: 1.1rem; }
.featured-section.collapsed .featured-row-wrap { display: none; }

.featured-row-wrap {
    position: relative;
}
.featured-row-wrap::after {
    content: '';
    position: absolute;
    right: 0; top: 0; bottom: 10px;
    width: 48px;
    background: linear-gradient(to right, transparent, color-mix(in srgb, #f97316 5%, var(--surface)));
    pointer-events: none;
    border-radius: 0 4px 0 0;
}
[data-theme="light"] .featured-row-wrap::after {
    background: linear-gradient(to right, transparent, color-mix(in srgb, #f97316 4%, #fff));
}

.featured-row {
    display: flex;
    gap: 0.9rem;
    overflow-x: auto;
    scrollbar-width: thin;
    scrollbar-color: rgba(249,115,22,0.55) rgba(255,255,255,0.06);
    padding-bottom: 10px;
}
.featured-row::-webkit-scrollbar { height: 6px; }
.featured-row::-webkit-scrollbar-track { background: rgba(255,255,255,0.05); border-radius: 3px; }
.featured-row::-webkit-scrollbar-thumb { background: rgba(249,115,22,0.55); border-radius: 3px; }
.featured-row::-webkit-scrollbar-thumb:hover { background: rgba(249,115,22,0.85); }
[data-theme="light"] .featured-row::-webkit-scrollbar-track { background: rgba(0,0,0,0.06); }

/* ── Grid ── */
.quiz-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
    gap: 0.9rem;
}

/* ============================================================
   CARD
   ============================================================ */
.quiz-card {
    background: var(--surface);
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    cursor: pointer;
    position: relative;
    --accent: var(--primary);
    transition: transform var(--t) var(--ease),
                box-shadow var(--t) var(--ease),
                border-color var(--t) var(--ease);
}
.quiz-card:hover {
    transform: translateY(-3px);
    border-color: var(--accent);
    box-shadow: 0 6px 24px rgba(0,0,0,0.3), 0 0 0 1px var(--accent);
}
.quiz-card.selected {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent);
}

/* Accent per categoria */
.quiz-card[data-cat="word"]      { --accent: var(--c-word); }
.quiz-card[data-cat="math"]      { --accent: var(--c-math); }
.quiz-card[data-cat="logic"]     { --accent: var(--c-logic); }
.quiz-card[data-cat="geography"] { --accent: var(--c-geography); }
.quiz-card[data-cat="gaming"]    { --accent: var(--c-gaming); }
.quiz-card[data-cat="music"]     { --accent: var(--c-music); }
.quiz-card[data-cat="movie"]     { --accent: var(--c-movie); }
.quiz-card[data-cat="sport"]     { --accent: var(--c-sport); }
.quiz-card[data-cat="history"]   { --accent: var(--c-history); }
.quiz-card[data-cat="trivia"]    { --accent: var(--c-trivia); }
.quiz-card[data-cat="other"]     { --accent: var(--c-other); }

/* Check mark (selected) */
.select-check {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.65rem;
    z-index: 10;
    opacity: 0;
    transform: scale(0.5);
    transition: opacity var(--t), transform var(--t);
}
.quiz-card.selected .select-check { opacity: 1; transform: scale(1); }

/* Favorite button */
.fav-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: rgba(0,0,0,0.5);
    color: rgba(255,255,255,0.5);
    font-size: 0.7rem;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 11;
    transition: all var(--t);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}
.fav-btn:hover { background: rgba(0,0,0,0.7); color: var(--c-fav); transform: scale(1.1); }
.fav-btn.fav-active { color: var(--c-fav); background: rgba(244,63,94,0.2); }
[data-theme="light"] .fav-btn { background: rgba(255,255,255,0.7); color: rgba(0,0,0,0.35); }
[data-theme="light"] .fav-btn:hover { background: rgba(255,255,255,0.9); }

/* Thumb */
.card-thumb {
    position: relative;
    height: 148px;
    overflow: hidden;
    background: var(--surface2);
    flex-shrink: 0;
}
.thumb-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: transform 0.4s var(--ease);
}
.quiz-card:hover .thumb-img { transform: scale(1.06); }

.thumb-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.8rem;
    background: linear-gradient(135deg, var(--bg2), var(--surface2));
    position: relative;
}
.thumb-placeholder::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg,
        color-mix(in srgb, var(--accent) 20%, transparent),
        transparent 65%);
}

/* Category badge */
.cat-badge {
    position: absolute;
    bottom: 8px;
    left: 8px;
    padding: 2px 8px;
    border-radius: 999px;
    font-size: 0.65rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    background: var(--accent);
    color: #000;
    z-index: 2;
}

/* Favicon */
.card-icon {
    position: absolute;
    top: 8px;
    left: 8px;
    width: 28px;
    height: 28px;
    border-radius: 7px;
    overflow: hidden;
    background: var(--surface);
    border: 1px solid var(--border2);
    z-index: 3;
    display: flex;
    align-items: center;
    justify-content: center;
}
.card-icon img { width: 100%; height: 100%; object-fit: contain; padding: 3px; }

/* Body */
.card-body {
    padding: 0.75rem 0.9rem 0.5rem;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
}
.card-name {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--text);
    line-height: 1.3;
    margin-left: 2.2rem; /* space for icon */
    transition: color var(--t);
}
.quiz-card:hover .card-name { color: var(--accent); }
.card-desc {
    font-size: 0.76rem;
    color: var(--text2);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Footer */
.card-footer {
    padding: 0.6rem 0.9rem;
    border-top: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.open-btn {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.35rem 0.8rem;
    background: var(--accent);
    color: #000;
    border-radius: 8px;
    font-size: 0.76rem;
    font-weight: 700;
    transition: all var(--t);
}
.open-btn .fa-external-link-alt { font-size: 0.65rem; opacity: 0.7; }
.open-btn:hover { filter: brightness(1.12); transform: translateY(-1px); }
.tap-hint {
    font-size: 0.68rem;
    color: var(--text3);
    font-style: italic;
}

/* Featured cards */
.featured-card { min-width: 210px; max-width: 210px; flex-shrink: 0; }
.featured-card .card-thumb { height: 124px; }

/* ── Empty state ── */
.empty-state {
    text-align: center;
    padding: 5rem 2rem;
    color: var(--text2);
}
.empty-state .fa-search { font-size: 2.5rem; opacity: 0.2; display: block; margin-bottom: 1rem; }
.empty-state p { font-size: 0.95rem; font-weight: 500; }

/* ── Footer ── */
footer {
    border-top: 1px solid var(--border);
    padding: 1.1rem 2rem;
    font-size: 0.8rem;
    color: var(--text2);
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}
footer a { color: var(--primary); font-weight: 600; }
footer a:hover { text-decoration: underline; }
.sep { opacity: 0.35; }

/* ── Animation ── */
@keyframes cardIn {
    from { opacity: 0; transform: translateY(10px); }
    to   { opacity: 1; transform: translateY(0); }
}
.quiz-card { animation: cardIn 0.28s var(--ease) both; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 860px) {
    .topbar { padding: 0.6rem 1rem; gap: 0.65rem; }
    .filterbar { padding: 0 1rem 0.5rem; }
    main { padding: 1rem 1rem 3rem; }
    .quiz-grid { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
}

@media (max-width: 600px) {
    .logo span { display: none; }
    .open-selected-btn span { display: none; }
    .quiz-grid { grid-template-columns: 1fr 1fr; gap: 0.65rem; }
    .card-thumb { height: 110px; }
    .tap-hint { display: none; }
    .sort-group { display: none; }
}

@media (max-width: 380px) {
    .quiz-grid { grid-template-columns: 1fr; }
}