/* buttons.css */
.back-btn, .refresh-btn {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-full);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.back-btn:hover, .refresh-btn:hover {
    background: rgba(255, 255, 255, 0.35);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn {
    font-family: var(--font-display);
    font-weight: 700;
    padding: var(--space-md) var(--space-xl);
    border-radius: var(--radius-full);
    border: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

.btn::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 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn:active {
    transform: translateY(-1px);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
}

.btn-secondary {
    background: linear-gradient(135deg, var(--secondary), var(--secondary-dark));
    color: white;
}

.btn-success {
    background: linear-gradient(135deg, var(--success), #059669);
    color: white;
}

.btn-warning {
    background: linear-gradient(135deg, var(--warning), #D97706);
    color: white;
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger), #DC2626);
    color: white;
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: white;
}

.btn:not([class*="btn-"]) {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
}

.action-btn {
    width: 44px;
    height: 44px;
    min-width: 44px;
    min-height: 44px;
    border-radius: var(--radius-full);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.1rem;
    color: white;
    border: none;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-sm);
    padding: 0;
    line-height: 1;
}

.action-btn i {
    font-size: 1.1rem;
    color: white;
    display: block;
}

.action-btn:hover {
    transform: scale(1.15);
    box-shadow: var(--shadow-md);
    opacity: 0.9;
}

.action-btn:active {
    transform: scale(1.05);
}

.mode-btn {
    font-family: var(--font-display);
    font-weight: 600;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-full);
    border: none;
    cursor: pointer;
    font-size: 0.9rem;
    background: transparent;
    color: var(--text-muted);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.mode-btn:hover {
    color: var(--primary);
    background: rgba(255, 107, 53, 0.1);
}

.mode-btn.active {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    box-shadow: var(--shadow-sm);
}

.pill-btn {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 9999px;
    padding: 6px 12px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    box-shadow: none;
    transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.pill-btn:hover {
    background: var(--bg-primary);
}

.word-card-pill {
    border: none;
    background: linear-gradient(135deg, var(--primary), var(--accent-pink));
    color: white;
    border-radius: 999px;
    padding: 8px 16px;
    font-weight: 700;
    font-size: 0.9rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.word-card-pill:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.word-card-pill:active {
    transform: translateY(0);
}

.btn-logout {
    padding: var(--space-xs) var(--space-md);
    background: rgba(239, 68, 68, 0.9);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-logout:hover {
    background: rgba(220, 38, 38, 0.9);
    transform: translateY(-1px);
}

.sync-btn {
    padding: var(--space-xs) var(--space-md);
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.35);
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    transition: all 0.3s ease;
}

.sync-btn:hover {
    background: rgba(255, 255, 255, 0.35);
    transform: translateY(-1px);
}

.sync-btn:disabled {
    opacity: 0.65;
    cursor: not-allowed;
    transform: none;
}

.guide-btn {
    padding: var(--space-xs) var(--space-md);
    background: rgba(255, 230, 109, 0.25);
    color: white;
    border: 1px solid rgba(255, 230, 109, 0.5);
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    transition: all 0.3s ease;
}

.guide-btn:hover {
    background: rgba(255, 230, 109, 0.4);
    transform: translateY(-1px);
}

.btn-small {
    padding: var(--space-xs) var(--space-sm);
    font-size: 0.85rem;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.3s ease;
    margin-right: var(--space-xs);
    font-weight: 600;
}

.btn-small:last-child {
    margin-right: 0;
}

.btn-small.btn-info {
    background: var(--info);
    color: white;
}

.btn-small.btn-info:hover {
    background: #2563EB;
    transform: translateY(-1px);
}

.btn-small.btn-success {
    background: var(--success);
    color: white;
}

.btn-small.btn-success:hover {
    background: #059669;
    transform: translateY(-1px);
}

.btn-small.btn-warning {
    background: var(--warning);
    color: white;
}

.btn-small.btn-warning:hover {
    background: #D97706;
    transform: translateY(-1px);
}

.btn-small.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-small.btn-danger:hover {
    background: #DC2626;
    transform: translateY(-1px);
}

.btn-small i {
    margin-right: var(--space-xs);
}

.btn:focus-visible,
.back-btn:focus-visible,
.refresh-btn:focus-visible,
.pill-btn:focus-visible,
.action-btn:focus-visible,
.mode-btn:focus-visible,
.login-btn:focus-visible,
.pronunciation-btn:focus-visible {
    outline: 3px solid rgba(255, 107, 53, 0.35);
    outline-offset: 2px;
}

@media (max-width: 768px) {
    .btn,
    .back-btn,
    .refresh-btn,
    .pill-btn,
    .action-btn,
    .mode-btn,
    .login-btn,
    .pronunciation-btn {
        min-height: 44px;
    }
}

@media (hover: none) {
    .btn:hover,
    .back-btn:hover,
    .refresh-btn:hover,
    .word-card-pill:hover,
    .action-btn:hover {
        transform: none;
        box-shadow: var(--shadow-sm);
    }
}