/* ── Кнопки ──────────────────────────────────────────────────────────────── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 22px;
    border-radius: 999px;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all var(--duration-base) var(--ease-smooth);
    position: relative;
    overflow: hidden;
    font-size: 0.95rem;
    font-family: inherit;
    line-height: 1;
}
.btn-sm { padding: 6px 14px; font-size: 0.85rem; }

.btn-primary {
    background: linear-gradient(135deg, var(--color-bordo-700), var(--color-bordo-600));
    color: var(--color-vanilla-50);
    box-shadow: 0 4px 16px rgba(139, 30, 45, 0.35);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(139, 30, 45, 0.5);
    color: var(--color-vanilla-50);
    text-decoration: none;
}
.btn-primary:active { transform: translateY(0); }
.btn-primary::before {
    content: '';
    position: absolute;
    top: 0; left: -100%;
    width: 100%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.6s;
}
.btn-primary:hover::before { left: 100%; }
.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-secondary {
    background: var(--glass-bg-strong);
    color: var(--color-bordo-700);
    border: 1.5px solid var(--color-bordo-700);
}
.btn-secondary:hover {
    background: var(--color-bordo-700);
    color: var(--color-vanilla-50);
    text-decoration: none;
}

.btn-ghost {
    background: transparent;
    color: var(--color-text);
}
.btn-ghost:hover {
    background: rgba(139, 30, 45, 0.08);
    text-decoration: none;
}

.btn-danger {
    background: var(--color-danger);
    color: white;
    border: none;
}
.btn-danger:hover {
    background: #9b1523;
    color: white;
    text-decoration: none;
}

/* ── Форми ───────────────────────────────────────────────────────────────── */
.form-group { margin-bottom: 20px; }
.form-label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    color: var(--color-text);
    font-size: 0.95rem;
}
.form-control {
    width: 100%;
    padding: 12px 16px;
    background: var(--glass-bg-strong);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    color: var(--color-text);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: border-color var(--duration-fast),
                box-shadow var(--duration-fast),
                background var(--duration-fast);
}
.form-control:focus {
    outline: none;
    border-color: var(--color-bordo-700);
    box-shadow: 0 0 0 4px rgba(139, 30, 45, 0.15);
    background: var(--color-vanilla-50);
}
select.form-control { cursor: pointer; }
textarea.form-control { resize: vertical; min-height: 80px; }
.form-error {
    color: var(--color-danger);
    font-size: 0.85rem;
    margin-top: 4px;
}

/* ── Тости ───────────────────────────────────────────────────────────────── */
.messages-stack {
    position: fixed;
    top: 100px; right: 24px;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 10px;
    pointer-events: none;
}
.toast {
    padding: 14px 22px;
    background: var(--glass-bg-strong);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-medium);
    border-left: 4px solid var(--color-bordo-700);
    min-width: 280px;
    max-width: 400px;
    animation: slideInRight 0.4s var(--ease-bounce);
    pointer-events: auto;
    font-size: 0.9rem;
}
.toast--success { border-left-color: var(--color-success); }
.toast--error { border-left-color: var(--color-danger); }
.toast--warning { border-left-color: var(--color-warning); }

/* ── Картки книг ─────────────────────────────────────────────────────────── */
.book-card {
    display: flex;
    flex-direction: column;
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: transform var(--duration-base) var(--ease-smooth),
                box-shadow var(--duration-base) var(--ease-smooth);
    transform-style: preserve-3d;
    will-change: transform;
}
.book-card:hover { box-shadow: var(--glass-shadow-hover); }

.book-card__cover {
    position: relative;
    aspect-ratio: 2 / 3;
    overflow: hidden;
}
.book-card__cover img {
    width: 100%; height: 100%;
    object-fit: cover;
    transition: transform var(--duration-slow) var(--ease-smooth);
    display: block;
}
.book-card:hover .book-card__cover img { transform: scale(1.06); }
.book-card__cover::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, transparent 60%, rgba(42, 26, 31, 0.3) 100%);
    pointer-events: none;
}
.book-card__cover .cover-placeholder {
    position: absolute;
    inset: 0;
    font-size: 4rem;
}
.book-card__badge {
    position: absolute;
    top: 12px; right: 12px;
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
    backdrop-filter: blur(8px);
    z-index: 1;
}
.book-card__badge--available { background: rgba(46, 125, 91, 0.85); color: white; }
.book-card__badge--unavailable { background: rgba(107, 88, 96, 0.85); color: white; }

.book-card__body {
    padding: 16px 18px 18px;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.book-card__title {
    font-family: var(--font-display);
    font-size: 1.05rem;
    line-height: 1.25;
    color: var(--color-text);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin: 0;
}
.book-card__author { color: var(--color-text-muted); font-size: 0.88rem; }
.book-card__category {
    font-size: 0.72rem;
    color: var(--color-bordo-700);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
}