/* =========================================
   4. МОДУЛЬ КАРТОЧЕК (CARDS)
   ========================================= */

#cards-screen {
    position: absolute;
    background: #cfd8dc;
    z-index: 45;
}

.cards-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, #b0bec5 0%, #cfd8dc 100%);
    z-index: 0;
}

.cards-header {
    position: relative;
    z-index: 10;
    width: 100%;
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-stack {
    position: relative;
    z-index: 5;
    flex: 1;
    width: 90%;
    max-width: 320px;
    margin: 10px auto 30px auto;
    display: flex;
    align-items: center;
    justify-content: center;
}

.discussion-card {
    width: 100%;
    height: 420px;
    background: white;
    border-radius: 24px;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.2);
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 30px;
    text-align: center;
    font-size: 1.4rem;
    color: #37474f;
    line-height: 1.5;
    position: relative;
    overflow: hidden;
}

.discussion-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 12px;
}

.discussion-card.easy::before {
    background: #66bb6a;
}

.discussion-card.medium::before {
    background: #42a5f5;
}

.discussion-card.hard::before {
    background: #ef5350;
}

.card-controls {
    position: relative;
    z-index: 10;
    width: 100%;
    display: flex;
    justify-content: center;
    gap: 50px;
    padding-bottom: 40px;
}

.control-btn {
    width: 75px;
    height: 75px;
    border-radius: 50%;
    border: none;
    font-size: 2rem;
    background: white;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.1s;
}

.control-btn:active {
    transform: scale(0.9);
}

.like {
    color: #66bb6a;
}

.dislike {
    color: #ef5350;
}

/* --- CARDS TABS --- */
.cards-filter-tabs {
    position: relative;
    z-index: 10;
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 20px;
}

.filter-tab {
    background: rgba(255, 255, 255, 0.4);
    border: none;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    color: #455a64;
    cursor: pointer;
    transition: all 0.2s;
    backdrop-filter: blur(4px);
}

.filter-tab.active {
    background: #fff;
    color: #d81b60;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}