/* ==========================================
   LOBBY SCREEN, SELECTION GRID & CARDS
   ========================================== */

.lobby-header {
    text-align: center;
    margin-bottom: 35px;
}

.lobby-header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--text-bright) 30%, #a88beb 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -1px;
    margin-bottom: 8px;
}

.lobby-header p {
    color: var(--text-muted);
    font-size: 1rem;
}

.quiz-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 10px;
}

.quiz-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 24px;
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 16px;
    position: relative;
    overflow: hidden;
}

.quiz-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary), var(--accent));
    opacity: 0.8;
}

.quiz-card:hover {
    background: var(--card-hover-bg);
    border-color: rgba(255, 255, 255, 0.1);
    transform: translateY(-3px) scale(1.01);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

.quiz-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.quiz-card-badge {
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--accent);
    background: rgba(0, 242, 254, 0.1);
    padding: 4px 10px;
    border-radius: 50px;
    border: 1px solid rgba(0, 242, 254, 0.2);
    letter-spacing: 0.5px;
}

.quiz-card-status {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
}

.quiz-card-status.completed {
    color: var(--success);
    background: rgba(0, 230, 118, 0.1);
    padding: 3px 10px;
    border-radius: 50px;
    border: 1px solid rgba(0, 230, 118, 0.2);
    font-weight: 700;
    display: inline-flex;
}

.quiz-card-body h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-bright);
    line-height: 1.4;
}

@media (max-width: 600px) {
    .lobby-header h1 {
        font-size: 2rem;
    }
}

/* ========================================================
   SUBJECT TABS NAVIGATION
   ======================================================== */
.quiz-tabs-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
    margin: 20px 0 30px 0;
    padding: 6px;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 16px;
}

.tab-btn {
    background: transparent;
    border: 1px solid transparent;
    color: var(--text-muted);
    padding: 10px 18px;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-smooth);
    display: flex;
    align-items: center;
    gap: 6px;
}

.tab-btn:hover {
    color: var(--text-bright);
    background: var(--card-hover-bg);
}

.tab-btn.active {
    color: var(--text-bright);
    background: rgba(138, 43, 226, 0.15);
    border-color: rgba(138, 43, 226, 0.3);
    box-shadow: 0 0 15px rgba(138, 43, 226, 0.2);
}

.subject-section {
    animation: fadeInTab 0.4s cubic-bezier(0.25, 0.8, 0.25, 1) forwards;
}

@keyframes fadeInTab {
    from {
        opacity: 0;
        transform: translateY(8px);
    }

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

/* ========================================================
   LOBBY CONTROLS & SORT SEGMENTED SWITCH
   ======================================================== */
.lobby-controls {
    display: flex;
    justify-content: flex-end;
    margin: 0 0 20px 0;
}

.segmented-control {
    display: flex;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 3px;
    gap: 4px;
}

.segmented-control .sort-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    padding: 6px 14px;
    border-radius: 9px;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.segmented-control .sort-btn:hover {
    color: var(--text-bright);
    background: rgba(255, 255, 255, 0.03);
}

.segmented-control .sort-btn.active {
    color: var(--text-bright);
    background: rgba(0, 242, 254, 0.15);
    box-shadow: 0 0 10px rgba(0, 242, 254, 0.1);
}

/* Collapse/Expand rules */
.subject-section.collapsed .quiz-grid {
    display: none;
}

.subject-section.collapsed .collapse-chevron {
    transform: rotate(180deg);
}

/* ========================================================
   CUSTOM MULTIPLAYER COMBAT ARENA STYLES
   ======================================================== */
#combat-quiz-screen .option-btn {
    transition: all 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

#combat-quiz-screen .option-btn:hover:not(:disabled) {
    transform: translateY(-2px) scale(1.01);
    box-shadow: 0 8px 20px rgba(255, 255, 255, 0.08);
}

#combat-quiz-screen .option-btn:active:not(:disabled) {
    transform: translateY(0) scale(0.99);
}

#combat-quiz-screen .option-btn:disabled {
    cursor: not-allowed;
}