.card-flip {
    perspective: 1000px;
    height: 300px;
}

.card-flip-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.6s;
    transform-style: preserve-3d;
}

.card-flip.flipped .card-flip-inner {
    transform: rotateY(180deg);
}

.card-front,
.card-back {
    position: absolute;
    inset: 0;
    backface-visibility: hidden;
    border-radius: 16px;
    overflow: hidden;
}

.card-back {
    transform: rotateY(180deg);
}

.cards-page .cards-hero {
    background:
        radial-gradient(120% 140% at 90% 0%, rgba(34, 211, 238, 0.22), transparent 58%),
        radial-gradient(110% 120% at 5% 100%, rgba(59, 130, 246, 0.2), transparent 62%),
        linear-gradient(160deg, #0f172a 0%, #020617 100%);
    box-shadow: 0 26px 70px rgba(2, 6, 23, 0.45);
}

.cards-page .cards-kicker {
    margin: 0;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: #67e8f9;
}

.cards-page .cards-stat-box {
    border: 1px solid rgba(148, 163, 184, 0.26);
    border-radius: 0.85rem;
    background: rgba(15, 23, 42, 0.78);
    padding: 0.72rem 0.82rem;
}

.cards-page .cards-stat-label {
    margin: 0;
    font-size: 0.72rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: #94a3b8;
}

.cards-page .cards-stat-value {
    margin: 0.18rem 0 0;
    font-size: 1.62rem;
    line-height: 1;
    font-weight: 800;
    color: #f8fafc;
}

.cards-page .cards-surface,
.cards-page .cards-empty-state {
    background: linear-gradient(165deg, rgba(15, 23, 42, 0.92), rgba(2, 6, 23, 0.97));
    box-shadow: 0 20px 48px rgba(2, 6, 23, 0.34);
}

.cards-page .cards-input {
    border: 1px solid #334155;
    background: #020617;
    color: #f1f5f9;
    transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.cards-page .cards-input::placeholder {
    color: #64748b;
}

.cards-page .cards-input:focus {
    outline: none;
    border-color: rgba(34, 211, 238, 0.78);
    box-shadow: 0 0 0 3px rgba(34, 211, 238, 0.16);
}

.cards-page .deck-tile {
    border: 1px solid rgba(71, 85, 105, 0.72);
    border-radius: 1rem;
    background: linear-gradient(168deg, rgba(30, 41, 59, 0.84), rgba(2, 6, 23, 0.92));
    padding: 1rem;
    transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.cards-page .deck-tile:hover {
    transform: translateY(-2px);
    border-color: rgba(34, 211, 238, 0.6);
    box-shadow: 0 18px 36px rgba(2, 6, 23, 0.46);
}

.cards-page .deck-tile-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 0.75rem;
}

.cards-page .deck-chip {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    border: 1px solid rgba(34, 211, 238, 0.28);
    background: rgba(34, 211, 238, 0.1);
    color: #cffafe;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 0.2rem 0.58rem;
    white-space: nowrap;
}

.cards-page .deck-sample {
    margin-top: 0.7rem;
    color: #94a3b8;
    font-size: 0.94rem;
    line-height: 1.45;
    display: -webkit-box;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 3;
    overflow: hidden;
}

.cards-page .deck-open {
    margin-top: 0.88rem;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    color: #67e8f9;
    font-size: 0.88rem;
    font-weight: 600;
}

.cards-page .cards-stats-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    border: 1px solid rgba(71, 85, 105, 0.76);
    border-radius: 999px;
    background: rgba(15, 23, 42, 0.88);
    color: #cbd5e1;
    font-size: 0.9rem;
    padding: 0.5rem 0.9rem;
}

.cards-page .cards-stats-pill strong {
    color: #f8fafc;
}

.cards-page .cards-toolbar {
    border: 1px solid rgba(51, 65, 85, 0.76);
    border-radius: 0.9rem;
    background: rgba(2, 6, 23, 0.62);
    padding: 0.72rem;
}

.cards-page .cards-action-btn {
    border: 1px solid rgba(71, 85, 105, 0.84);
    border-radius: 0.72rem;
    background: rgba(15, 23, 42, 0.86);
    color: #e2e8f0;
    font-size: 0.86rem;
    font-weight: 600;
    padding: 0.5rem 0.78rem;
    transition: border-color 0.18s ease, background 0.18s ease, color 0.18s ease;
}

.cards-page .cards-action-btn:hover {
    border-color: rgba(34, 211, 238, 0.62);
    background: rgba(8, 47, 73, 0.54);
    color: #e0f2fe;
}

.cards-page .cards-action-btn[aria-pressed='true'] {
    border-color: rgba(34, 211, 238, 0.7);
    background: rgba(14, 116, 144, 0.35);
    color: #ecfeff;
}

.cards-page .cards-grid .study-card {
    transition: transform 0.18s ease;
}

.cards-page .cards-grid .study-card:hover {
    transform: translateY(-2px);
}

.cards-page .cards-grid .card-flip {
    height: 330px;
    cursor: pointer;
}

.cards-page .cards-grid .card-flip-inner {
    border: 1px solid rgba(71, 85, 105, 0.7);
    border-radius: 1rem;
    background: linear-gradient(170deg, rgba(15, 23, 42, 0.96), rgba(2, 6, 23, 1));
    box-shadow: 0 18px 40px rgba(2, 6, 23, 0.45);
}

.cards-page .cards-grid .card-front,
.cards-page .cards-grid .card-back {
    border-radius: 1rem;
    background: transparent;
    border: 0;
    color: #e2e8f0;
}

.cards-page .cards-grid .card-body {
    display: flex;
    flex-direction: column;
    height: 100%;
    padding: 1rem;
    overflow: hidden;
}

.cards-page .cards-grid .card-topline {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.65rem;
}

.cards-page .cards-grid .card-meta {
    font-size: 0.71rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: #67e8f9;
    font-weight: 700;
}

.cards-page .cards-grid .card-index {
    border: 1px solid rgba(71, 85, 105, 0.9);
    border-radius: 999px;
    padding: 0.14rem 0.48rem;
    font-size: 0.71rem;
    color: #94a3b8;
}

.cards-page .cards-grid .card-text {
    flex: 1 1 auto;
    min-height: 0;
    overflow: auto;
    line-height: 1.57;
    color: #f8fafc;
}

.cards-page .cards-grid .card-text p {
    margin: 0 0 0.65rem 0;
}

.cards-page .cards-grid .card-text img,
.cards-page .cards-grid .card-text .card-inline-image {
    display: block;
    max-width: 100%;
    height: auto;
    border-radius: 0.6rem;
    border: 1px solid rgba(71, 85, 105, 0.72);
    margin: 0.45rem 0;
}

.cards-page .cards-grid .card-text table {
    width: 100%;
    border-collapse: collapse;
    margin: 0.5rem 0;
}

.cards-page .cards-grid .card-text th,
.cards-page .cards-grid .card-text td {
    border: 1px solid rgba(71, 85, 105, 0.72);
    padding: 0.32rem 0.44rem;
    vertical-align: top;
}

.cards-page .cards-grid .card-text code {
    background: rgba(15, 23, 42, 0.8);
    border: 1px solid rgba(71, 85, 105, 0.65);
    border-radius: 0.4rem;
    padding: 0.1rem 0.28rem;
    font-size: 0.86em;
}

.cards-page .cards-grid .card-text pre {
    overflow: auto;
    border: 1px solid rgba(71, 85, 105, 0.65);
    border-radius: 0.65rem;
    background: rgba(2, 6, 23, 0.7);
    padding: 0.55rem 0.65rem;
}

.cards-page .cards-grid .card-hint {
    margin-top: 0.55rem;
    font-size: 0.72rem;
    color: #64748b;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.cards-page .cards-grid .answer-chip {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    border: 1px solid rgba(56, 189, 248, 0.34);
    background: rgba(14, 116, 144, 0.17);
    color: #bae6fd;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.2rem 0.52rem;
    margin-bottom: 0.45rem;
}

.cards-page .cards-no-results {
    margin-top: 0.82rem;
    color: #94a3b8;
    font-size: 0.9rem;
}

.cards-focus-mode #cardsGrid {
    grid-template-columns: minmax(0, 1fr) !important;
    max-width: 860px;
    margin-inline: auto;
}

.cards-focus-mode .cards-grid .card-flip {
    height: 390px;
}

@media (max-width: 767.98px) {
    .cards-page .cards-grid .card-flip {
        height: 300px;
    }

    .cards-focus-mode .cards-grid .card-flip {
        height: 320px;
    }
}